Canine mixed tumors as one of the mammary neoplasia varieties

The most significant interest in veterinary oncology is occupied by tumors of a mixed nature, which are represented by the direct interaction of epithelial and mesenchymal components. According to some data, the formation of cell lineage of mesenchymal cells occurs due to the transformation of epidermal basket cells surrounding the glandular epithelium. In this case, the formation of a cartilage anlage with its further transformation into differentiated bone tissue occurs. The article contains information about the structure and features of the location and interaction of mixed tumors' glandular and stromal components in female dogs (n=29). It was revealed that in addition to simple mixed neoplasms, tumors with proplasia of the mesenchymal component into highly differentiated cartilage or bone tissue were also often registered. To confirm subcellular changes in the expression of certain types of proteins, such as a-SMA and vimentin, an IHC study was used. The expression of the studied biomarkers was established in mesenchymal fibroblastic differon cells and myoepithelial cells. The intensity of immunoreactive material expression ranged from moderate (2+) to strong (3+), indicating changes in myoepithelial cells' genotype during the formation of mixed mammary neoplasms.(AU)

Clinical presentation, histological findings, and prognosis in female dogs with mixed mammary neoplasms / Apresentação clínica, achados histológicos e prognóstico em cadelas com neoplasias mamárias mistas

The aim of this study was to describe the clinical and morphological characteristics of mixed mammary neoplasms and verify what characteristics affect the prognosis of female dogs with carcinomas in mixed tumors and carcinosarcomas. This was a retrospective study of 67 female dogs that underwent mastectomies and were diagnosed with benign mixed tumors (n=13), carcinomas in mixed tumors (n=44) and carcinosarcomas (n=10). Data regarding the clinical and histological aspects of the neoplasms were collected and the relation with specific survival times, and hazard ratios (HR) in 24 months was calculated. In univariate analysis, the diagnosis of carcinosarcoma (HR 8.26, p=0.006), carcinomatous areas with micropapillary or solid patterns (HR 17.49; p=0. 001) and lymph node metastasis (HR 7.07;p=0.020) were associated with specific survival. In multivariable analysis, only micropapillary or solid pattern (HR=16.34; p=0.007) remained independent factor associated with lower specific survival. Micropapillary or solid carcinomatous patterns were associated with shorter specific survival time (p=0.002) among animals with carcinomas in mixed tumors. Among the carcinosarcomas, lymph node metastasis (p=0.010) was associated with a shorter specific survival time. In conclusion, carcinomas in mixed tumors and carcinosarcomas vary in prognosis depending on the carcinomatous proliferation patterns and spread of the disease.

O objetivo deste estudo foi descrever as características clínicas e morfológicas das neoplasias mamárias mistas e verificar quais características interferem no prognóstico de cadelas com carcinomas em tumores mistos e carcinossarcomas. Este foi um estudo retrospectivo de 67 cadelas, que foram submetidas a mastectomias e diagnosticadas com tumores mistos benignos (n = 13), carcinomas em tumores mistos (n = 44) e carcinossarcomas (n = 10). Foram coletados dados sobre os aspectos clínicos e histológicos das neoplasias e a relação com o tempo de sobrevida específica e a razão de risco (OR) em 24 meses foram calculadas. Na análise univariada, o diagnóstico de carcinossarcoma (HR 8,26; p=0,006), as áreas carcinomatosas com padrão micropapilar e sólido (HR 17,49; p= 0,001) e metástase linfonodal (HR 7,07; p=0,020) foram associadas à menor sobrevida específica. Na análise multivariável, apenas o padrão micropapilar ou sólido (HR=16,34; p=0,007) permaneceu como fator independente associado à sobrevida. Proliferações carcinomatosas micropapilares ou sólidas (p = 0,002) foram associadas a tempos de sobrevida específica mais curtos entre os animais com carcinomas em tumor misto. Entre os pacientes com carcinossarcoma, metástases em linfonodos (p = 0,010) foram associadas a um menor tempo de sobrevida específica. Em conclusão, os resultados mostraram que os carcinomas em tumores mistos e os carcinossarcomas podem ter prognóstico variável, dependendo do padrão de proliferação carcinomatosa e da disseminação linfática da doença.

Quality of breast reconstruction service at a university hospital as assessed by the patients

Purpose: To evaluate the quality of breast reconstruction service at a university hospital, as assessed by the patients. Methods: This cross-sectional study enrolled adult women who underwent immediate or delayed breast reconstruction by any technique performed at a university hospital between 1 and 24 months before the assessment. The Brazilian version of the Health Service Quality Scale (HSQS) was self-applied to the participants. The HSQS produces percentage scores, which are expressed in values ranging from 0 to 10 for each domain of the scale, and into an overall percentage quality score. The management team was asked to establish a minimum satisfactory score for the breast reconstruction service. Results: Ninety patients were included. The management team considered 8.00 the minimum satisfactory score for the service. The overall percentage score was 93.3%. Only one domain, 'Support,' had an average score lower than that considered satisfactory (7.22 ± 3.0); while the others had higher scores. The domain that scored highest was 'Qualification' (9.94 ± 0.3), followed by 'Result' (9.86 ± 0.4). There was a positive correlation between 'type of oncologic surgery' and 'intentions of loyalty to the service' (ρ = 0.272; p = 0.009) and a negative correlation between 'education' and 'quality of the environment' (ρ = ­0.218; p = 0.039). The higher the patient's level of education, the higher the score attributed to 'relationship' (ρ = 0.261; p = 0.013) and the lower the score of 'aesthetics and functionality' (ρ = ­0.237; p = 0.024). Conclusion: The quality of the breast reconstruction service was considered satisfactory, but there is a demand for structural improvements, better interpersonal relationships, and a stronger support network for patients.

Diagnostic applicability of infrared thermography in the evaluation of canine mammary tumors / Aplicabilidade diagnóstica da termografia infravermelha na avaliação dos tumores mamários caninos

Mammary tumors have a high prevalence in bitches and women, and are related to high rates of morbidity and mortality. For the human species, thermography has stood out as a diagnostic tool for breast cancer. However, its clinical benefit in bitches remains unknown. Thus, the goal of the present study was to evaluate the diagnostic applicability of infrared thermography for canine mammary tumors, as well as to correlate tumor temperature with mitotic index and tumor volume. Thermographic and digital images of eight bitches with mammary neoplasms were captured. Thermograms were entered into the FLIR tools software and the temperature of 15 tumor and 15 healthy glands from the contralateral mammary chain was analyzed. There was no significant difference (p = 0.786) between the mean temperature of neoplastic (33.71°C ± 1.86) and healthy (33.54°C ± 1.59) glands. There was a negative and moderate correlation between tumor temperature and mitotic index (ρ = -0.52 p = 0.049). However, no correlation was detected between mammary temperature and tumor volume (p = 0.10). Although thermography allowed no distinction between neoplastic and healthy mammary glands in bitches, it may be promising to assess the proliferative rate of tumors. In addition, malignant neoplasms may be more often hypothermic than healthy tissue.(AU)

Os tumores mamários apresentam alta prevalência em cadelas e mulheres, sendo relacionados a elevadas taxas de morbidade e mortalidade. Para a espécie humana, a termografia tem se destacado como ferramenta diagnóstica do câncer de mama. Entretanto, o seu benefício clínico em cadelas permanece desconhecido. Assim, o objetivo do presente estudo foi ava-liar a aplicabilidade diagnóstica da termografia infravermelha para os tumores mamários caninos, bem como correlacionar a temperatura tumoral com o índice mitótico e volume tumoral. Foram capturadas imagens termográficas e digitais de oito cadelas com neoplasias mamárias. Os termogramas foram inseridos no software FLIR tools e analisou-se a temperatura de 15 mamas tumorais e 15 hígidas da cadeia mamária contralateral. Não houve diferença significativa (p = 0,786) entre a tempera-tura média das glândulas neoplásicas (33,71°C ± 1,86) e saudáveis (33,54°C ± 1,59). Houve correlação negativa e moderada entre a temperatura tumoral e índice mitótico (ρ = -0,52 p = 0,049). Entretanto, não foi observada correlação entre tempe-ratura e volume tumoral (p = 0,10). Apesar da termografia não ter permitido a diferenciação das mamas neoplásicas e saudá-veis de cadelas, ela pode ser uma forma promissora para avaliação da taxa proliferativa dos tumores. Além disso, as neoplasias malignas podem apresentar-se mais frequentemente hipotérmicas em relação ao tecido saudável.(AU)

Efficacy of fine needle aspiration in the diagnosis of spontaneous mammary tumors / Eficácia da citologia aspirativa no diagnóstico de tumores mamários espôntaneos / La eficacia de la aspiración con aguja fina en el diagnóstico de tumores mamarios espontáneos

The cytopathology exam has been utilized to diagnose mammary disorders in female dogs. The success of cytopathology results depends on, among other factors, the diagnostic accuracy of the exam. The present study aimed to compare the cytopathological and histopathological findings from mammary disorder cases in female dogs and evaluate the lesion cytopathology exam accuracy. The concordance degree was evaluated between the cytopathology and histopathology exams of 67 female dogs, carriers of palpable breast lumps, cared for at the university hospital from which the following indicators were calculated: sensitivity, specificity, positive predictive value, negative predictive value, false positives, false negatives, and exam accuracy. The sensitivity was 95.23%, the specificity 75%, positive predictive value 98.36%, negative predictive value 60%, and accuracy 94.02%. There were 2 false negatives and 1 false positive. In conclusion the cytopathology exam can be amply utilized as a means of diagnosis with high accuracy and sensitivity in the first examination of female dogs with mammary tumors.(AU)

O exame citológico tem sido utilizado no diagnóstico das afecções mamárias das cadelas. O êxito no resultado da citologia dependerá, além de outros fatores, da acurácia diagnóstica deste exame. O objetivo deste estudo foi comparar os achados citológicos e histológicos das afecções mamárias de cadelas e avaliar a acurácia do exame citológico nestas lesões. Avaliou-se o grau de concordância entre os exames citológico e histológico de 67 cadelas, portadoras de nódulo mamário palpável, atendidas em um hospital universitário e foram calculados os indicadores: sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, falso positivo, falso negativo e acurácia do exame. A sensibilidade foi de 95,23%, a especificidade de 75%, o valor preditivo positivo de 98,36%, o valor preditivo negativo de 60% e a acurácia de 94,02%. Ocorreu 1 resultado falso positivo e 2 falso negativos. Conclui-se que o exame citológico pode ser amplamente utilizado como meio de diagnóstico com elevada acurácia e sensibilidade no atendimento primário das cadelas com tumor de mama.(AU)

El examen citológico se ha usado en el diagnóstico de cáncer de mama en perras. El éxito de la citología depende, entre otros factores, la precisión diagnóstica de este examen. El objetivo de este estudio fue comparar los resultados de citología y examen histológico de las enfermedades de mama en las perras y evaluar la exactitud de la citología de estas lesiones. Se evaluó el grado de acuerdo entre los exámenes citológicos e histológicos de 67 perros, que sufren de bulto palpable en la mama atendidos en un hospital universitario y se calcularon los indicadores: sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo, falsos positivos, falsos negativo y exactitud de la prueba. La sensibilidad fue del 95,23%, especificidad 75%, valor predictivo positivo del 98,36%, valor predictivo negativo del 60% y el 94,02% de precisión. Hubo un resultado positivo falso y dos falsos negativos. Se concluye que el examen citológico puede ser ampliamente utilizado como una herramienta de diagnóstico de alta precisión y sensibilidad en la atención primaria de perros con cáncer de mama. (AU)

CA 15-3, CRP, and LDH correlates with prognostic parameters in canine mammary neoplasms

The identification of putative prognostic factors in canine mammary neoplasms (CMNs) has been focused on tissue-specific biomarkers, but the serum biomarkers, including cancer antigen 15-3 (CA 15-3), c-reactive protein (CRP), and lactate dehydrogenase (LDH) have been demonstrated to display clinical application in cases of CMNs. The aim of the study was to evaluate the levels of these serum biomarkers and their association with well-established prognostic factors in CMNs. Samples from 15 female canines with CMNs and 15 clinically healthy ones were collected. The results were evaluated using the Tukey's, Pearson, or Spearman tests. The cut-off point, sensitivity, specificity, and area under curve (AUC) were evaluated using the receiver operating characteristic (ROC) curve analysis in a logistic regression model (P<0.05). The levels of CA 15-3, CRP and LDH were significantly higher in the serum of female dogs with CMNs compared to the healthy ones. Moreover, these factors were positively correlated with ulceration, tumor size, histopathological grade, metastatic lymph node, and clinical staging. Female dogs with CMNs were found to exhibit highest serum levels of CA 15-3, CRP, and LDH. Therefore, they can be applied to improve the efficacy of the diagnosis and prognostic evaluation in casas of CMNs.(AU)

A comparative analysis of anatomopathological features and COX-2 expression of mammary neoplasms with malignant mesenchymal components in female dogs / Análise comparativa das características anatomopatológicas e expressão de COX2 em neoplasias mamárias com componentes mesenquimais malignos em cadelas

ABSTRACT: Canine mammary neoplasms with malignant mesenchymal components, such as carcinosarcomas and sarcomas, belong to an uncommon and histologically heterogeneous group. Little is known about the biological behavior of these histogenic variants. This study aimed to compare the clinicopathological characteristics and the COX-2 immunohistochemical expression of different histologic subtypes of carcinosarcomas and sarcomas. Samples of 23 carcinosarcomas and 15 sarcomas from the mammary glands of female dogs were studied. Medical records were reviewed to obtain clinical data. Subsequently, histology microscope slides were analyzed to assess for mesenchymal subtypes, necrosis, vascular invasion, histologic grades, and lymph node metastasis. Immunohistochemistry was used to assess the COX-2 expression. The malignant mesenchymal proliferation was categorized into osteosarcomas (23/40), fibrosarcomas (5/40), liposarcomas (6/40) and chondrosarcomas (4/40). The osteosarcomatous differentiation was the most predominant type among the sarcomas and carcinosarcomas and was associated with vascular invasion (P=0.010) and lymph node metastases (P=0.014). High COX-2 expression was detected in 14.3% of the carcinosarcomas (carcinoma and/or sarcoma cells) and 27.3% of the sarcomas. The carcinosarcomas and sarcomas had similar clinical and pathological characteristics and developed as large tumors, with intratumoral necrosis and a predominance of high histologic grades, although the frequency of vascular invasion and lymph node metastasis was low. Osteosarcoma subtypes presented more aggressive characteristics than non-osteosarcoma subtypes.

RESUMO: Neoplasias mamárias caninas com componentes mesenquimais malignos, como carcinossarcomas e sarcomas, são um grupo de neoplasias pouco frequentes e histologicamente heterogêneas e pouco se sabe sobre o comportamento biológico das variantes histogênicas. O objetivo desse estudo é comparar as características anatomopatológicas e a expressão imunoistoquímica de COX-2 de diferentes subtipos histológicos de carcinossarcomas e sarcomas. Foram estudados 23 carcinosarcomas e 17 sarcomas da glândula mamária de cadelas. Os prontuários médicos foram revisados para obtenção de dados clínicos. Posteriormente, as lâminas histológicas foram avaliadas para acessar os subtipos mesenquimais, necrose, invasão vascular, grau histológico, metástase linfonodal. A imunoistoquímica foi realizada para avaliar a expressão de COX-2. Os tipos encontrados de proliferação mesenquimal maligna foram osteossarcoma (23/40), fibrossarcoma (7/40), lipossarcoma (6/40) e condrossarcoma (4/40). A diferenciação osteossarcomatosa foi predominante entre os sarcomas e carcinossarcomas e foi associado com invasão vascular (P=0,006) e metástase linfonodal (P=0,014). Uma expressão alta de COX-2 foi detectada em 14,3% dos carcinossarcomas (células carcinomatosas e/ou sarcomatosas) e 27,3% dos sarcomas. Os carcinossarcomas e sarcomas apresentaram características clínicas e patológicas semelhantes e se desenvolveram como tumores grandes, com necrose intratumoral e predomínio de alto grau histológico, mas com baixa frequência de invasão vascular e metástase distante. Os subtipos osteossarcomatosos apresentaram características mais agressivas quando comparados com subtipos não osteossarcomatosos.

Diagnosis of transmissible venereal tumors in bitches - platelet indices are a remarkable marker?

Background: Hematological analyses are seen as more preferred laboratory analyses in canine transmissible venereal tumor studies. There is no information about the availability of platelets and their indices in routine practice in canine transmissible venereal tumor cases. Taking this as a starting point, this study analyzed the usefulness of platelet indices in dogs with transmissible venereal tumor in clinical laboratory diagnosis as well as examined the relationship between white blood cells, red blood cells, platelets (PLT), main platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT), and the ratio of main platelet volume to platelets (MPV/PLT). Materials, Methods & Results: In the study, a total of 42 bitches of various breeds were used. Nineteen healthy bitches were used as a control group, and the others 23 with cTVT as a study group. Metastasis was not observed in any of the bitches involved in the study. History, clinical findings, and cytological examinations were evaluated for the diagnosis of cTVT. In animals with hemorrhagic discharge and neoplastic lesions, a vaginal cytological examination was performed. Typical TVT cells with large nuclei and intracytoplasmic vacuoles were observed in the vaginal cytological examinations, and the diagnosis of TVT was made. Healthy bitches (19) and those with TVT (23) were 39.16 5.37 months and 47.61 5.14 months old, respectively. From all animals, 2 mL blood samples were collected from V. cephalica to evaluate PIs in the complete blood count (CBC). Collected blood samples were analyzed using an automated hematology analyzer. As a result of the analysis, WBC, RBC, HGB, HCT, MCV, MCHC, RDW, PLT, MPV, PDW, PCT, and MPV/PLT data were obtained. Mild leukocytosis, an increase in PLT, and a decrease in MCV and MPV/PLT were determined in the study group compared to the control group. Cut-off values in CBC of bitches with TVT were determined as WBC: 13.35 (sensitivity: 78%; specificity: 90%); MCV: 67 (sensitivity: 57%; specificity: 95%); PLT: 315.50 (sensitivity: 65%; specificity: 74%); and MPV/PLT: 0.028 (sensitivity: 78%; specificity: 58%). In CBC analyses, a strong negative correlation between PLT and MPV/PLT was detected in both groups. Discussion: Canine transmissible venereal tumors are common in both stray and pet dogs. It is naturally transferred from animal to animal during mating by live tumor cells. This tumor can commonly affect the external genitalia and internal organs in some cases. It generally has the look of cauliflower, and its surface is ulcerated, inflammatory, hemorrhagic, and infectious. More preferred laboratory analyses are complete blood count and blood chemistry analysis in cTVT for to evaluate the success of treatments. Platelet indices have been investigated in many diseases such as endotoxemia, chronic enteropathy, mammary tumor, parvoviral enteritis, septic peritonitis, lymphoma, pyometra, visceral leishmaniasis, and babesiosis in dogs. There is no information available for either diagnostic or prognostic use of the PIs in canine TVT cases. Ultimately, in light of the presented study's results, platelet indices, especially PLT and the MPV/PLT ratio, seem to be notable laboratory markers in terms of easy accessibility and low-cost assessment techniques in canine transmissible venereal tumor cases. New data, however, should be established by a thorough follow-up study using a larger sample size and addressing its usefulness as a diagnostic or prognostic marker in canine transmissible venereal tumors.

Extraskeletal osteosarcoma in the duodenum of a dog

Background: Osteosarcoma is the most observed primary bone tumor in dogs, and may affect the appendicular and axial skeletons. In addition, it may be present in extraskeletal form, accounting for only 1% of cases. As shown by few reports in the literature, the involvement of the intestinal region by is rare. The objective of this study was to report the case of a 13-year-old Yorkshire dog, submitted to an exploratory laparotomy for suspected partial intestinal obstruction, diagnosed with extraskeletal osteosarcoma. Case: A 13-year-old dog, Yorkshire Terrier, male, presented clinical signs of gastrointestinal abnormalities. An ultrasound examination was performed and was found a mass in small intestine region with wall and lumen invasion. Then, was realized exploratory laparotomy and detected intestinal obstruction due to a mass with approximately 5.0 x 6.0 x 4.4 cm localized in duodenum. Surgical removal was performed and the sample sent to the veterinary diagnostic laboratory for histopathological examination. The sample had an irregular surface and firm consistency. In addition, when cut, the mass enveloped the intestinal layers and sometimes obstructed the lumen. Then, the sample were processed routinely for histopathology. After that, in microscopy evaluation was detected cell proliferation, affecting all layers of intestine. In detail, cells were elongated with pleomorphism marked and atypical mitosis. In addition, there was production of cartilage and bone matrix. So, due the absence of others sites, the neoplasm was considered primary of intestine. After that, to evaluate the expression of KI-67 and COX-2 was performed, and the cell proliferation index was 54.0% and the COX-2 expression was moderate in less than 10% of neoplastic cells. After the surgery, the patient was hospitalized for a week and continue the treatment in home. Afterwards, the tutor received the diagnosis, but even though he was instructed on the severity of the case, he chose not to undergo chemotherapy. After three months, the patient presented abdominal fluid and nodules in your liver, suggesting metastasis, but without diagnosis confirmation. The patient died five months after the diagnosis of extraskeletal osteosarcoma. However, no necropsy was realized, impossibility the diagnosis confirm. Discussion: The frequency of extraskeletal osteosarcoma in dogs remains unknown, with the mammary glands being the most affected site. In the present study, osteosarcoma affects the duodenal region and no reports of this neoplasm in the duodenum of dogs have been found in the literature. The clinical sign of dyschezia was important for the tutor to refer the animal to the veterinarian and perform the ultrasound in an attempt to elucidate the case, as the tumor mass is not always palpable. Histopathological examination and immunohistochemistry were necessary for the differential diagnosis and to establish the prognosis, although after the surgery the tutor chose not to perform chemotherapy. Extraskeletal osteosarcoma are usually highly metastatic, mainly affecting the lymph nodes and liver. In this case, the patient presented a liver nodule three months after the tumor removal surgery, but unfortunately, there was no diagnostic confirmation. Such neoplastic type is rarer and more aggressive than appendicular and axial osteosarcoma, with an average survival of 1 to 3 months. In this case, as a necropsy was not obtained, we cannot attribute the survival time to the disease. The survival rates of osteosarcomas in dogs are few months, but in the present case, although the patient died five months after surgery, the failure to perform a necropsy compromises the attribution of survival time to extraskeletal osteosarcoma.

Canine mammary neoplasms - evaluation of tumor microenvironment

Background: The tumor microenvironment is an important target of studies in different types of neoplasms. Understanding the role of general components such as immune, vascular and fibroblastic cells has the objective of contributing to prognosis and treatment. The aim of this study was to evaluate the relationship between mast cells and angiogenesis in benign and malignant mammary neoplasms by investigating the role of degranulation and microlocation of mast cells and neoformed vessels in canine mammary neoplasms. Materials, Methods & Results: Mammary glands (n = 122) from 50 female dogs submitted to mastectomy without chemotherapy were evaluated and categorized into 3 groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. To evaluate the MCD (mast cell density) and angiogenesis, Toluidine Blue (0.1%) and Gomori’s Trichrome techniques were performed and adapted from previous studies. Photomicrographs of 10 hotspot areas on a 40x objective lens of the mammary glands and lymph nodes were captured to assess MCD and angiogenesis. In the absence of these areas, random fields were captured. For the mammary glands of the malignant and benign groups, 20 fields were analyzed, as the analysis considered the microlocation (peritumoral and intratumoral). Counting was performed manually using ImageJ software version 1.42q by 2 observers. The statistical analysis were performed using SPSS software version 19.0. The most frequent histological type in the malignant group was carcinoma in mixed tumor (68.42%; 39/57) and in the benign group was benign mixed tumor (57.89%; 11/19). Female dogs without breed pattern were more frequently affected represented 70% of the animals and the mean age was 9 years and 8 months ± 3 years and 1 month...

Canine mammary neoplasms - evaluation of tumor microenvironment

Background: The tumor microenvironment is an important target of studies in different types of neoplasms. Understanding the role of general components such as immune, vascular and fibroblastic cells has the objective of contributing to prognosis and treatment. The aim of this study was to evaluate the relationship between mast cells and angiogenesis in benign and malignant mammary neoplasms by investigating the role of degranulation and microlocation of mast cells and neoformed vessels in canine mammary neoplasms. Materials, Methods & Results: Mammary glands (n = 122) from 50 female dogs submitted to mastectomy without chemotherapy were evaluated and categorized into 3 groups: control group (n = 46); malignant group (n = 57) and benign group (n = 19). Lymph nodes without changes (n = 59) and with metastases (n = 6) were also evaluated. To evaluate the MCD (mast cell density) and angiogenesis, Toluidine Blue (0.1%) and Gomoris Trichrome techniques were performed and adapted from previous studies. Photomicrographs of 10 hotspot areas on a 40x objective lens of the mammary glands and lymph nodes were captured to assess MCD and angiogenesis. In the absence of these areas, random fields were captured. For the mammary glands of the malignant and benign groups, 20 fields were analyzed, as the analysis considered the microlocation (peritumoral and intratumoral). Counting was performed manually using ImageJ software version 1.42q by 2 observers. The statistical analysis were performed using SPSS software version 19.0. The most frequent histological type in the malignant group was carcinoma in mixed tumor (68.42%; 39/57) and in the benign group was benign mixed tumor (57.89%; 11/19). Female dogs without breed pattern were more frequently affected represented 70% of the animals and the mean age was 9 years and 8 months ± 3 years and 1 month...(AU)

The prognostic value of serum neoplastic biomarkers CA 15-3 and CEA in canine mammary neoplasms: a review / O valor prognóstico dos biomarcadores neoplásicos séricos CA 15-3 e CEA em neoplasias mamárias caninas: uma revisão

As neoplasias mamárias caninas (NMCs) são as mais frequentes em cadelas, com isso, uma grande variedade de técnicas tem sido utilizada para identificar os seus fatores prognósticos. Dentre as possibilidades, os biomarcadores neoplásicos séricos antígeno do câncer (CA 15-3) e o antígeno carcinoembrionário (CEA) são os mais promissores. Biomarcadores neoplásicos são substâncias presentes na neoplasia, sangue ou demais produtos biológicos, produzidos pela neoplasia, ou secundariamente pelo paciente, em resposta à sua presença. Na medicina veterinária, esses marcadores são pouco estudados. Em termos gerais, eles não podem ser usados para o diagnóstico primário de neoplasias mamárias, mas estão relacionados com os fatores prognóstico já bem estabelecidos na literatura e tem como vantagem se tratar de uma análise menos invasiva e que é possível de ser feita de forma seriada. O objetivo desta revisão é descrever o CA 15-3 e o CEA como biomarcadores utilizados nas NMCs, o progresso recente feito na literatura e providenciar um sumário dos principais resultados já obtidos. O CA 15-3 e o CEA apresentam potencial prognóstico nas NMCs. Apesar de existir uma grande variação de resultados para esses biomarcadores na literatura, o seu uso deve ser considerado, visto os resultados obtidos na caracterização e prognóstico das NMC.(AU)

Female canine mammary neoplasms (CMNs) are the most frequent neoplasm in bitches, and a variety of techniques have been used to identify they prognostic factors. Among the possibilities, the serum biomarkers cancer antigen (CA 15-3) and carcinoembryonic antigen (CEA) are the most reliable. Neoplastic biomarkers are substances present in the neoplasia, blood, or other biological products, produced mainly by the neoplasia, or secondarily by the patient, in response to their presence. In veterinary medicine, these biomarkers are poorly studied. In general terms they cannot be used for primary diagnosis of mammary neoplasms but are related to the prognostic factors and have the advantage of being a less invasive analysis and that it is possible to be done in a serial way. The objective of this review is to describe CA 15-3 and CEA use as biomarkers in CMNs, the recent progress made in literature and the main overall results that had been already obtained. CA 15-3 and CEA have prognostic potential for CMNs. There is a wide variation of results for these biomarkers in literature, but despite this, its use must be considered as they provide relevant results in terms of characterization and prognostic in CMNs.(AU)

Association between vitamin D and malignant mammary tumors in obese female dogs

Overweight and obesity are known risk factors that are involved in the development and aggressiveness of breast tumors in women. In situations of obesity, local and systemic inflammation may worsen the prognosis of oncological patients. Moreover, hypovitaminosis D increases the risk of breast tumors in women. In female dogs, low vitamin D levels have been found in cases of lymphoma, osteosarcoma and mast cell tumor. The present study aimed to make correlations between body fat composition and serum 25(OH)D concentration in female dogs with mammary tumors. Two experimental groups were formed: healthy female dogs (n = 12; control group) and female dogs with mammary tumors (n = 11). An analysis on body composition was performed using dual-energy X-ray absorptiometry (DXA) equipment. In the tumor group, multicentric nodules were most prevalent (63,6%), with diameters of up to 8.2 cm. The most frequent histopathological diagnosis was tubular carcinoma (45.5%), and 9.1% presented metastases in axillary lymph nodes. The mean 25(OH)D concentration in the female dogs with mammary tumors (37.6 ng mL-1) was lower than the level in the control group (65.4 ng mL-1). Multivariate statistical analysis showed that elderly female dogs with malignant mammary tumors and high body fat levels presented lower 25(OH)D concentrations than those of the control group. It was concluded that female dogs with higher body adiposity presented mammary tumors of higher aggressivity, and that the higher the fat percentage was in the female dogs with malignant mammary tumors, the lower their vitamin D concentration was.(AU)

Hematological and biochemical alterations in female dogs with mammary cancer and inflammatory carcinoma / Alterações hematológicas e bioquímicas em cadelas com neoplasias mamárias e carcinoma inflamatório

Hematological and biochemical alterations in animals with neoplasms may result from the direct effects of tumor growth or paraneoplastic syndromes. The objective of this study was to evaluate these hematological and biochemical alterations in female dogs with mammary tumors and with inflammatory carcinoma (IC). Blood samples were collected from 43 female dogs divided into three groups according to clinical staging: Group 1 (G1) - animals in initial stage (T1,2,3N0M0, N=17), Group 2 (G2) - animals in advanced stage (T1,2,3N1M0,1, N=15) and Group 3 (G3) - animals presenting IC (N=11). Hematological and biochemical parameters obtained were related to patients' clinical staging. Among alterations, the most common were anemia, neutrophilic leukocytosis, monocytosis, increased ALT, AST, and hypoalbuminemia, mainly in dogs in advanced clinical staging and with inflammatory carcinoma.

Aterações hematológicas e bioquímicas em animais portadores de neoplasias podem resultar dos efeitos diretos do crescimento tumoral ou de síndromes paraneoplásicas. O objetivo deste estudo foi avaliar as alterações hematológicas e bioquímicas em cadelas com neoplasias mamárias e carcinoma inflamatório (IC). Foram coletadas amostras de sangue de 43 cadelas divididas em três grupos de acordo com o estadiamento clínico: grupo 1 (G1) - cadelas em estádio inicial (T1,2,3N0M0, N=17), grupo 2 (G2) - cadelas em estádio avançado (T1,2,3N1M0,1, N=15) e grupo 3 (G3) - cadelas que apresentaram IC (N=11). Os parâmetros hematológicos e bioquímicos obtidos foram relacionados com o estadiamento clínico das pacientes. Entre as alterações, as mais comuns foram anemia, leucocitose neutrofílica, monocitose, aumento de ALT, AST e hipoalbuminemia, principalmente em cadelas em estadiamento clínico avançado e com carcinoma inflamatório.

The effect of size and clinical staging of mammary tumors on blood parameters in bitches

Background: Mammary tumors are the most common type of tumor in female dogs and account for 50% of all tumors in dogs. The clinical prognosis of canine mammary tumors is strongly affected by the size, stages, histological type, and grade of tumor; mitotic index; and nearby and distant metastasis. In canine mammary tumors, it is recommended that prognostic evaluation should also include complete blood count, serum biochemistry, and blood gases in addition to tumor size and stage. This study aimed to investigate the effect of tumor size, volume, and clinical stage on complete blood count, blood gas analysis, and serum biochemical parameters in bitches with mammary tumors and the correlation between them. Materials, Methods & Results: The study included a total of 18 bitches of different breeds, aged 6-15 years, of which 12 had mammary tumors and 6 were healthy. Thoracic X-rays were performed on bitches with mammary tumors in ventrodorsal and laterolateral positions to evaluate lung metastasis. Blood samples were collected from the cephalic vein from bitches in both groups in 2 different tubes (with plastic gel and ethylenediaminetetraacetic acid), 5 mL each, to perform complete blood count and evaluate blood gases and serum biochemical parameters. Blood samples were collected from the animals at the time of initial examination without any intervention. Analysis of the blood showed that bitches with mammary tumors had decreased levels of RBC, HCT, HGB, potassium, TCO2 , base excess, THbc, and ALT enzyme activity and increased levels of lactate, total protein, cholesterol, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities compared with those in the control group. Furthermore, the dogs with a primary tumor of > 5 cm were found to have significantly higher levels of WBC, lactate, total protein, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities and significantly lower levels of RBC and THbc compared with those in the control group. Bitches with tumors in multiple mammary lobes were found to have significantly higher levels of WBC, total protein, triglyceride, LDL, and ALP and LDH enzyme activities and significantly lower levels of RBC, HCT, HGB, TCO2 , THbc, and ALT enzyme activity compared with those in the control group. Based on the laboratory findings and approval of the owners of the dogs, mammary tissues containing the tumor and lymph nodes were surgically removed. After the operation, the removed mammary tissues were evaluated for size and volume. Clinical staging of the tumors was performed based on the size of the primary tumor (T), nearby lymph nodes (N), and metastasis (M) in accordance with the criteria set by WHO. Clinical staging of the tumors was, thus, based on the tumor, nodes, and metastases (TNM) score obtained according to the following system: Stage I: T1 N0 M0 , Stage II: T2 N0 M0 , Stage III: T3 N0 M0 , Stage IV: TanyN1 M0 , Stage V: made as TanyNanyM1 . Discussion: Mammary tumors are the most common type of neoplasm in bitches and, thus, cause serious problems in veterinary medicine. Tumors are significantly correlated with better prognosis compared with larger tumors. Based on this finding, this study investigated the effect of size, volume, and stage of mammary tumors in bitches on some blood parameters and the correlation between them. Therefore, it was concluded that clinical staging and evaluation of blood parameters could be useful in the diagnosis, treatment, and prediction of prognosis in canine mammary tumors. This study found that bitches with mammary tumors exhibited significant changes in their blood parameters (complete blood count, blood gas analysis, and serum biochemistry). The results obtained from this study may contribute to the development of approaches to the diagnosis, prediction of prognosis, and treatment of canine mammary tumors.

Epidemiological, clinical, and histopathological aspects of mammary neoplasms in dogs from Rio Branco, Acre, Brazil / Aspectos epidemiológicos, clínicos e histopatológicos das neoplasias mamárias em cães do município Rio Branco, Acre, Brasil

Mammary neoplasms are very common in the clinical routine of small animals and have an enormous histological diversity and complexity. Most of these neoplasms are classified as malignant and originate from metastases, considered the main cause of death. This study aimed to present and correlate epidemiological data with the malignancy of histological types of mammary neoplasms in dogs in the municipality of Rio Branco, Acre, Brazil. The analyzed samples were collected in collaborating hospitals and veterinary clinics, the data acquired through a questionnaire filled in by them, the clinical staging carried out through the TNM system, and the histological classification according to the Consensus regarding the Diagnosis, Prognosis, and Treatment of Canine and Feline Mammary Tumors. The fixed material was evaluated macroscopically and then subjected to classical histological processing. Histological preparations were observed under optical microscopy. The data were organized statistically using Pearson's chi-square test (p<0.05). Of the 71 samples obtained from dogs, 50 consisted of mammary neoplasms, 18 skin neoplasms, and three non-tumor lesions. Eleven breeds of dogs were identified. Among them, 48 were females and two males with an average age of 10 years and most patients intact (90%) and the minority used progestogens (16%). Of the mammary neoplasms, 94% had a malignant profile, with carcinoma in a mixed tumor being the most frequent (60%). Statistically, no correlation was observed between breed, sex, age, reproductive status, use of progestogens, mammary location, or tumor size with malignancy. In general, dogs can be affected by malignant mammary neoplasms, regardless of the mentioned variables, reinforcing the importance of clinical staging and early diagnosis for the best prognosis within the small animal clinic.

As neoplasias mamárias são muito frequentes na rotina clínica de pequenos animais e possuem uma enorme diversidade e complexidade histológica. A maior parte dessas neoplasias é classificada como malignas e originam às metástases, sendo consideradas a principal causa mortis. Este estudo objetivou apresentar e correlacionar os dados epidemiológicos com a malignidade dos tipos histológicos das neoplasias mamárias em cães dentro do município de Rio Branco, Acre. As amostras analisadas foram coletadas em hospitais e clínicas veterinárias colaboradoras, os dados adquiridos através de questionário preenchido pelos mesmos, o estadiamento clínico realizado através do sistema TNM e a classificação histológica segundo o Consenso de Diagnóstico, Prognóstico e Tratamento de Neoplasias Mamárias Caninas. O material fixado foi avaliado macroscopicamente e, em seguida, submetido ao processamento histológico clássico. As preparações histológicas foram observadas sob microscopia óptica. Os dados obtidos foram organizados na forma estatística utilizando o Teste de Qui-quadrado de Pearson (p<0,05). Das 71 amostras obtidas em cães, 50 foram neoplasias mamárias, 18 foram tumores de pele e três eram lesões não tumorais. Foram identificadas 11 raças caninas, 48 eram fêmeas e dois machos, com idade média de 10 anos, onde a maioria dos pacientes eram inteiros (90%) e a minoria fazia uso de progestágenos (16%). Das neoplasias mamárias, 94% apresentaram o perfil maligno, sendo o carcinoma em tumor misto o mais frequente (60%). Estatisticamente não houve correlação entre raça, sexo, idade, estado reprodutivo, uso de progestágenos, localização das mamas ou tamanho tumoral com a malignidade. A espécie canina de modo geral pode ser acometida de neoplasia mamária maligna, independente das variáveis citadas, reforçando a importância do estadiamento clínico e diagnóstico precoce para o melhor prognóstico dentro da clínica de pequenos animais.

EpCAM expression in canine malignant mammary tumors - immunohistochemical study

Background: Epithelial cell adhesion molecule (EpCAM) is a glycoprotein responsible for multiple cellular functions that includes cell-to-cell adhesion and signal transduction. Studies in human breast cancer demonstrated that its overexpression has been linked to a more aggressive histological phenotype. However, in canine mammary tumors, its use is still scarce and its function, remains unknown. The main goal of the present study was to characterize the expression of EpCAM in canine mammary malignant tumors and associate its expression with clinicopathological features. Materials, Methods & Results: Forty-eight canine mammary samples were analyzed in the present study and went through the Hematoxylin-Eosin (HE) routine technique for histopathological and immunohistochemical analysis. EpCAM expression was evaluated considering the total immunolabelling (TI) which consists of the addition of 2 parameters: proportion score (PS) and intensity score (IS). Thirteen (27.1%) cases showed weak expression, 9 (18.7%) were characterized by a moderate expression and 27 (54.2%) were classified as intense. EpCAM overexpression was described in 36 (72.9%) primary tumors and in 5 lymph node metastases (71.4%). Immunoreactivity was, mainly, characterized by a staining in the lateral cell membrane of luminal epithelial cells, both in primary tumors and lymph node metastases. The statistical analysis was performed using the SPSS Statistics, version 24. Clinicopathological features, such as histological grade (P = 0.027), intravascular emboli (P = 0.004) and lymph node metastases (P = 0.016) demonstrated to be associated with a more aggressive histological type. Intravascular emboli and lymph node metastases were also linked to a higher histological grade. Discussion: EpCAM overexpression has been described in the literature both in canine mammary tumors and breast cancer. While the results in breast cancer could be ambiguous, depending on the tumor subtype, in the present study our findings demonstrated that overexpression was present in more than 50% of the total cases evaluated. In addition, immunoreactivity was also in accordance with the literature that describes membranous staining as the most prevalent pattern type. It was not possible to correlate overexpression with histological type and histological grade. However, those clinicopathological features are essential to evaluate tumor prognosis. For instance, our results demonstrated that histological type was statistically significant with histological grade (P = 0.027), intravascular emboli (P = 0.004) and lymph node metastases (P = 0.016). Additionally, the Nottingham system was statistically significant with intravascular emboli (P = 0.033) and lymph node metastases (P = 0.006). These findings have also been described in similar studies using canine mammary tissues in bitches. When it comes to pattern of expression in primary tumors and lymph nodes metastases, our findings described that neoplastic cell presented the same phenotype in these 2 different locations. In addition, loss of expression was also described in cluster cells within the subcapsular area which reflects the idea that the expression of EpCAM molecule changes according to time, which could be translated into the multistep process of metastases. Finally, it demonstrates that the development of neoplasia is not something static, but rather dynamic.

Phytochemical and biological attributes of Bauhinia variegata L. (Caesalpiniaceae) / Atributos fitoquímicos e biológicos de Bauhinia variegata L. (Caesalpiniaceae)

Bauhinia variegata plant is a very popular and traditionally potent ethnomedicine. Therefore, it is need of hour to study ameliorative characteristics of B. variegata for novel secondary metabolites. The current study was designed to explore antiproliferative potential of B. variegata due to scant reports on this aspect. Extracts of various parts (flowers, leaves, bark, stem, and roots) were prepared by successive maceration using organic solvents in increasing order of polarity (n-hexane, ethyl acetate, methanol, and water). The determination of polyphenolic contents was done by using colorimetric methods while antioxidant potential was measured using reducing power assay. Brine shrimp lethality assay was performed for determining preliminary cytotoxicity and antiproliferative activity against breast cancer MCF-7 cell line using MTT protocols. Moreover, antimicrobial activities were detected by using disc diffusion assay. The alpha-amylase assay was performed to monitor the antidiabetic potential of the plant. In case of phytochemical analysis methanolic extract of leaves and bark showed highest phenolic and flavonoids contents. n-Hexane and ethyl acetate extracts of stem and roots exhibited more than 90% mortality with LD50 ranges between 1-25 µg/mL when studied by brine shrimp lethality assay. n-Hexane and ethyl acetate extracts of roots and stem also showed antiproliferative activity against human breast cancer MCF-7 cell line with IC50 values ranges between 12.10-14.20 µg/mL. Most of the extracts displayed moderately high antibacterial and antifungal activities. The n-hexane extract of roots showed antidiabetic activity with 60.80 ± 0.20% inhibition of alpha-amylase. In sum, these preliminary results will be useful for further compound isolation from selected plant parts for the discovery of antibacterial, antidiabetic, and anticancer lead candidates.

A planta Bauhinia variegata é uma etnomedicina muito popular e tradicionalmente potente. Portanto, as características de melhoria de B. variegata foram estudadas. Foi avaliada a determinação dos teores antioxidantes e polifenólicos. O ensaio de letalidade do camarão de salmoura foi realizado para determinar a citotoxicidade preliminar e a atividade antiproliferativa contra linhas de células de câncer de mama MCF-7 usando protocolos de MTT. Além disso, foram detectadas atividades antimicrobianas. O ensaio da alfa-amilase foi realizado para monitorar o potencial antidiabético da planta. Dentre vinte amostras diferentes, o extrato metanólico (EM) da casca apresentou os maiores teores fenólicos totais. A EM das folhas apresentou excelente conteúdo de flavonoides, atividade antioxidante significativa foi exibida pelo extrato hexânico do caule. O extrato do caule de hexano exibe 77,40% como citotóxico em DL50 10,50 µg/mL quando avaliado através do ensaio de letalidade de artêmia. Extratos de hexano e acetato de etila de raiz e caule mostraram atividade antiproliferativa contra a linhagem celular MCF7 de câncer de mama humano (IC50 12,10-14,20 µg/mL). Para potencial antimicrobiano importante, vários extratos exibiram excelentes atividades antibacteriana e antifúngica, enquanto o extrato de n-hexano da raiz mostrou atividade antidiabética (60,80 ± 0,20% na concentração de 200 µg/mL). Em suma, estes resultados preliminares serão úteis para isolamento adicional de compostos a partir de partes de plantas selecionadas para a descoberta de candidatos a antibacterianos, antidiabéticos e anticâncer.

Bone and pulmonary metastasis from a mammary adenosquamous carcinoma in a bitch / Metástase óssea e pulmonar de adenocarcinoma escamoso mamário em cadela

Mammary tumors are the most common in bitches, and bone and pulmonary metastases are not well described. Adenosquamous mammary carcinoma is a rare tumor that can be classified as a type of metaplastic tumor. This report describes the clinical and histopathological findings of this atypical presentation of mammary carcinoma in an 11-year-old, spayed, Poodle. Surgery was performed to remove malignant mammary nodules with a provisional diagnosis of carcinoma on cytologic examination. Thirteen months later, the dog returned showing left pelvic limb lameness that had persisted for 6 months prior to the consultation. The patient showed right pelvic limb lameness and a mass in the same limb. Radiographs of the affected limb revealed a pathological fracture in the femoral diaphysis and proliferation of the periosteum. After clinical staging, a left pelvic limb amputation was performed. A diagnosis of grade II adenosquamous mammary carcinoma was made through histopathology and immunohistochemistry. Although uncommon, bone and pulmonary metastases from mammary tumors, such as adenosquamous carcinoma, can be considered differential diagnoses for bony tumors. This report highlights the aggressive nature and significant metastatic potential of the adenosquamous carcinoma.

Os tumores mamários são os mais comuns em cadelas e as metástases ósseas e pulmonares não são bem descritas. O carcinoma mamário adenoescamoso é um tumor raro que pode ser classificado como um tipo de tumor metaplásico. Este relato descreve os achados clínicos e histopatológicos dessa apresentação atípica de carcinoma mamário em um Poodle de 11 anos de idade, castrado. A cirurgia foi realizada para remover nódulos mamários malignos com diagnóstico provisório de carcinoma no exame citológico. Treze meses depois, a cadela retornou apresentando claudicação do membro pélvico esquerdo que persistia por seis meses antes da consulta. O paciente apresentava claudicação do membro pélvico direito e uma massa no mesmo membro. A radiografia do membro afetado revelou fratura patológica na diáfise femoral, proliferação do periósteo e áreas de osteopenia. Após estadiamento clínico, foi realizada amputação do membro pélvico esquerdo. O diagnóstico de carcinoma adenoescamoso mamário grau II foi feito através da histopatologia e imunohistoquímica. Embora incomuns, as metástases ósseas e pulmonares de tumores mamários, como o carcinoma adenoescamoso, podem ser consideradas diagnósticos diferenciais para tumores ósseos. Este relatório destaca a natureza agressiva e significativo potencial metastático do carcinoma adenoescamoso.

Expression of LIN28A/B and Let-7 miRNAs in canine mammary carcinomas / Expressão de LIN28A/B e Let-7 miRNAs em carcinomas mamários caninos

LIN28 is a RNA-binding protein including two highly conserved homologous, LIN28A and LIN28B. Proto-oncogenes such as LIN28A and LIN28B are generally targeted by the let-7 miRNAs in different types of human cancers. Here, we determined the expression of LIN28A in canine mammary tumor samples and the LIN28/let-7 pathway in canine mammary cell lines. In those cell lines, we identified a functional LIN28/let-7 pathway which exhibited high expression of let-7 members and low expression of its targets, including LIN28A and LIN28B. However, the mammary carcinoma tissue samples showed a frequent expression of LIN28A being expressed mainly in the epithelial cells. No association was observed between LIN28A expression and histopathological classification and grade, TNM and survival time. Our results suggested a possible role of the LIN28A protein in the development of canine mammary carcinomas due to the high frequency observed in the tumor samples (28 of 32). The in vitro experiments suggested that the LIN28/let-7 pathway is active in the tumor cells evaluated. However, more studies are necessary to elucidate the exact role of LIN28/let-7 pathway in canine mammary carcinomas.

LIN28 é uma proteína de ligação ao RNA, com duas formas homólogas altamente conservadas, LIN28A e LIN28B. Os proto-oncogenes LIN28A e LIN28B são regulados pela família de miRNAs let-7 em diferentes tipos de cânceres em humanos. No presente trabalho, o objetivo foi determinar a expressão de LIN28A em amostras de tumor mamário de cadelas e a via LIN28/let-7 em linhagens celulares mamárias caninas. Nestas linhagens, através das técnicas de qPCR e RNAseq, foi identificado que a via LIN28/let-7 apresenta-se funcional, com alta expressão dos membros da família let-7 e baixa expressão de seus alvos, entre eles LIN28A e LIN28B. No entanto, as amostras de tecidos de carcinomas mamários caninos demonstraram expressão frequente de LIN28A, sendo observada principalmente em células epiteliais. Não foram observadas associações entre expressão de LIN28A com classificação e gradação histopatológicas, TNM e tempo de sobrevida. Nossos resultados sugerem uma possível relação da proteína LIN28A no desenvolvimento de carcinomas mamários caninos devido à alta frequência observada nas amostras tumorais (28 de 32). Os experimentos in vitro sugerem que a via LIN28/let-7 é ativa nas linhagens celulares caninas avaliadas. Entretanto, estudos funcionais ainda são necessários para elucidar a função exata da via LIN28/let-7 nos carcinomas mamários caninos.