Physicians' attitudes and perceived barriers to adherence to the national breast cancer clinical practice guidelines in Mexico: a survey study.

BACKGROUND: Adherence to clinical practice guidelines improves outcomes for patients with breast cancer. However, their implementation may not be feasible in low- and middle-income countries. This study aimed to evaluate physicians' adherence, attitudes, and barriers towards the Colima Consensus, which is the Mexican national breast cancer clinical practice guideline. METHODS: A cross-sectional, 31-item survey was e-mailed to Consensus attendees and members of the Mexican Society of Oncology and Mexican Mastology Association. Descriptive statistics, univariate, and multivariate analysis were used to analyze the associations between participants' characteristics, adherence, attitudes, and barriers. RESULTS: Of 439 respondents, 78% percent adhered to Consensus recommendations and 94% believed it was applicable to their clinical practice. Forty percent reported using the Consensus as their sole breast cancer guideline. This was associated with being a surgical oncologist (OR 3.3, 95% CI 2.0-5.3) and practicing at a public hospital (OR 2.1, 95% CI 1.2-3.7). The most common barriers to adherence were lack of resources and logistical problems. Regarding attitudes towards the Consensus, 90% considered it a good educational tool, 89% considered it a reliable source of information, and 90% thought it improved quality of care. CONCLUSIONS: We showed high levels of adherence and positive attitudes towards the Colima Consensus, with a significant proportion of physicians using it as their only guideline. Lack of resources and logistical issues were the main barriers to adherence. Our results highlight the relevance of local breast cancer guidelines and suggest a need for the creation of resource-stratified guidelines.

Effectiveness of ultrasound in the detection of axillary metastasis in patients with breast cancer without clinical evidence of axillary disease: Clinical impact / Efectividad de la ecografía en la detección de metástasis axilares en pacientes con cáncer de mama sin evidencia clínica de enfermedad axilar: impacto clínico

Introduction Preoperative ultrasound in patients with breast cancer without evidence of clinical axillary disease represents an attempt to reliably identify axillary lymph node metastasis. However, the usefulness of ultrasound for the detection of axillary disease should be evaluated. Materials and methods The study included a retrospective cohort of 826 patients with diagnosed invasive breast cancer, treated at the National Cancer Institute of Mexico, from 2014 to 2018. All patients underwent ipsilateral axillary ultrasound for staging purposes. Besides the descriptive analysis of the preoperative ultrasound, findings of the cohort were compared with their corresponding cytology and histopathology reports. Results Diagnostic index for axillary ultrasound was calculated as follows: 32.8% sensitivity, 82.5% specificity, 37.1% positive predictive value (PPV), 79.6% negative predictive value (NPV), 70.6% diagnostic accuracy, 1.86 positive likelihood ratio (LR+), and 0.81 negative likelihood ratio (LR−). Loss of fatty hilum was associated with a higher risk of axillary metastasis on the multivariate analysis (OR 3.645; 95% CI, 1.664–7.985, p<0.001). Conclusions The utility of axillary ultrasound as a method of determining the nodal status prior to surgery in patients with breast cancer without clinical evidence of axillary disease was not demonstrated in this study. (AU)

Introducción La ecografía preoperatoria en pacientes con cáncer de mama sin evidencia de enfermedad clínica axilar representa un intento de identificar de manera confiable metástasis a ganglios linfáticos axilares. Sin embargo, se debe evaluar la utilidad de la ecografía para la detección de la enfermedad axilar. Material y métodos El estudio incluyó una cohorte retrospectiva de 826 pacientes con cáncer de mama invasivo diagnosticado en el Instituto Nacional de Cancerología de México, de 2014 a 2018. Todos los pacientes se sometieron a una ecografía axilar ipsilateral con fines de estadificación. Además del análisis descriptivo de la ecografía preoperatoria, los resultados de la cohorte se compararon con sus correspondientes informes de citología e histopatología. Resultados Los índices diagnósticos para la ecografía axilar fueron: 32,8% de sensibilidad, 82,5% de especificidad, 37,1% de valor predictivo positivo (VPP), 79,6% de valor predictivo negativo (VPN), 70,6% de precisión diagnóstica, 1,86 de razón de verosimilitud positiva (LR+) y 0,81 de razón de verosimilitud negativa (LR−). La pérdida de hilio graso se asoció con un mayor riesgo de metástasis axilares en el análisis multivariado (RM: 3.645; IC al 95%: 1.664-7.985; p<0,001). Conclusiones La utilidad de la ecografía axilar como método para determinar el estado ganglionar antes de la cirugía en pacientes con cáncer de mama sin evidencia clínica de enfermedad axilar no se demostró en este estudio. (AU)

The Role of Postmastectomy Radiotherapy in Locally Advanced Breast Cancer After Pathological Complete Response to Neoadjuvant Chemotherapy.

The Case A previously healthy woman, aged 32 years, presented to the oncology clinic with a 6-month history of left-breast tumor, mastalgia, and swollen axillary nodes. Physical examination was relevant for a 6-cm palpable mass in the upper outer quadrant of the left breast and an ipsilateral 2-cm, nonfixed axillary lymph node. Mammography showed a 1-cm mass in the upper outer quadrant, a 5.2-cm mass in the lower outer quadrant, and enlarged pathologic lymph nodes (BI-RADS category 5 disease). Breast ultrasound revealed 3 axillary lymph nodes with cortical thickening and loss of normal morphology (the largest with a 2.6-cm length in the long axis) (Figure 1A-B). The breast´s core biopsy revealed a grade 3 apocrine invasive carcinoma with lymphovascular invasion; immunohistochemistry testing showed HER2-negative, hormone receptor-negative disease (estrogen receptor, 0%; progesterone receptor, 0%; HER2-negative, Ki67, 50%) (Figure 2A-B). A fine-needle aspiration biopsy of the axillary lymph nodes showed invasive breast carcinoma as well. Bone scintigraphy and a chest/abdomen CT scan ruled out metastatic disease. Upon initial diagnosis, clinical stage was deemed as cT3N1M0 (American Joint Committee on Cancer 8th edition: anatomic stage IIIA, clinical prognostic stage IIIC). After a multidisciplinary tumor board discussion, the patient underwent neoadjuvant chemotherapy with weekly paclitaxel, followed by 4 cycles of dose-dense doxorubicin plus cyclophosphamide. After completing neoadjuvant treatment, clinical examination was relevant for a residual 1-cm palpable left breast mass and no palpable axillary nodes. Mammography and breast ultrasound showed a 77% partial response in the primary tumors, and axillary nodes with normal morphology and size (Figure 1C-D). Due to multicentric tumor disease, breast-conserving surgery would not confer satisfactory cosmetic results on her, and a modified radical mastectomy with intraoperative sentinel lymph node biopsy (and second-stage breast reconstruction) was planned. However, during surgery, the surgeons failed to identify the mapped lymph node, and level I-III axillary lymph node dissection was performed. The pathology report described complete pathological response: Miller and Payne criteria grade 5 response with the absence of malignant cells within the mastectomy specimen and in 24 lymph nodes (Figure 2C-E). Pathological staging after neoadjuvant treatment concluded ypT0N0M0 disease. Subsequent treatment for this patient was discussed in another tumor board.

Radiotherapy in women with epithelial ovarian cancer: historical role, current advances, and indications.

Epithelial ovarian cancer (OC) is known to be a neoplasm responsive to radiotherapy (RT). Nevertheless, the role of RT in the management of this disease represent a topic of controversy, and the indications for its use are not fully established. Initial studies suggested that the addition of RT in the form of intraperitoneal (IP) radioisotopes was useful. Indications for this treatment were peritoneal cytology with tumor cells, peritoneal implants, and capsule rupture. The instillation of radioisotopes was contraindicated when macroscopic residual disease was present. Pelvic RT was used after surgery in patients with an absence of gross residual disease. Early studies established the inadequacy of this technique and the need for treating the whole abdomen. Whole abdominal irradiation (WAI) was a therapeutic tool used in the prechemotherapy era to eradicate large amounts of microscopic peritoneal disease. Ideal candidates for WAI were stage I patients with grade 2 or 3 tumors; stage II patients with grade 1 or 2 tumors and residual disease, and stage III, grade 1 patients with <2 cm residual disease. The disadvantages of WAI were the dose-limiting toxicities, which were predominantly acute hematologic and late gastrointestinal. The era of aggressive debulking and platinum agents made WAI fall out of favor as a treatment of OC. Selective approaches with highly conformal radiotherapy (CRT) have been used in case of limited recurrent or unresectable disease with the potential for long-term disease control. Currently, the role of RT in OC applies for patients with recurrent oligometastatic or oligoprogressive disease and in the palliative setting for symptom control. We performed a nonsystematic review and included data from both retrospective and prospective studies focusing on the use of RT for OC and its biological rationale. Furthermore, ongoing trials on this issue are reported.

Radiotherapy for the treatment of pituitary adenomas: A dosimetric comparison of three planning techniques.

AIM: Our goal was to compare conformal 3D (C3D) radiotherapy (RT), modulated intensity RT (IMRT), and volumetric modulated arc therapy (VMAT) planning techniques in treating pituitary adenomas. BACKGROUND: RT is important for managing pituitary adenomas. Treatment planning advances allow for higher radiation dosing with less risk of affecting organs at risk (OAR). MATERIALS AND METHODS: We conducted a 5-year retrospective review of patients with pituitary adenoma treated with external beam radiation therapy (C3D with flattening filter, flattening filter-free [FFF], IMRT, and VMAT). We compared dose-volume histogram data. For OARs, we recorded D2%, maximum, and mean doses. For planning target volume (PTV), we registered V95%, V107%, D95%, D98%, D50%, D2%, minimum dose, conformity index (CI), and homogeneity index (HI). RESULTS: Fifty-eight patients with pituitary adenoma were included. Target-volume coverage was acceptable for all techniques. The HI values were 0.06, IMRT; 0.07, VMAT; 0.08, C3D; and 0.09, C3D FFF (p < 0.0001). VMAT and IMRT provided the best target volume conformity (CI, 0.64 and 0.74, respectively; p < 0.0001). VMAT yielded the lowest doses to the optic pathway, lens, and cochlea. The position of the neck in extreme flexion showed that it helps in planning mainly with VMAT by allowing only one arc to be used and achieving the desired conformity, decreasing the treatment time, while allowing greater protection to the organs of risk using C3D, C3DFFF. CONCLUSIONS: Our results confirmed that EBRT in pituitary adenomas using IMRT, VMAT, C3D, C3FFF provide adequate coverage to the target. VMAT with a single arc or incomplete arc had a better compliance with desired dosimetric goals, such as target coverage and normal structures dose constraints, as well as shorter treatment time. Neck extreme flexion may have benefits in treatment planning for better preservation of organs at risk. C3D with extreme neck flexion is an appropriate treatment option when other treatment techniques are not available.

The impact of the use of intraoperative radiotherapy on costs, travel time and distance for women with breast cancer in the Mexico City Metropolitan Area.

BACKGROUND AND OBJECTIVES: The low availability and poor access to external beam radiotherapy (EBRT) in developing countries makes it hard for women with breast cancer to receive breast conservation. We studied the effect of providing intraoperative radiotherapy (IORT) on the travel time, distance, and costs of in the Mexico City Metropolitan Area (MCMA). METHODS: Sixty-nine patients treated between January 2013 and September 2014 were analyzed. Travel distance and transit time was calculated using Google Maps. The time and distance patients living in the MCMA treated with IORT would have spent if they had received EBRT was calculated. Cost analysis for each modality was performed. RESULTS: 71% (n = 49) lived in the MCMA. Sixteen (33%) received additional EBRT and 33 (66%) received IORT only. Mean driving distance and transit time of those 33 women was 132.6 km (SD 25.7) and 66 min (SD 32.9). Patients from the MCMA receiving IORT alone avoided 990 visits, 43 700 km and 65 400 min in transit. IORT led to a 12% reduction in costs per patient. CONCLUSIONS: By reducing costs and time needed for patients to receive radiotherapy, IORT could potentially enhance access to breast conservation in resource-limited developing countries.

Implementation of intensity modulated radiotherapy for prostate cancer in a private radiotherapy service in Mexico.

Intensity modulated radiation therapy (IMRT) allows physicians to deliver higher conformal doses to the tumour, while avoiding adjacent structures. As a result the probability of tumour control is higher and toxicity may be reduced. However, implementation of IMRT is highly complex and requires a rigorous quality assurance (QA) program both before and during treatment. The present article describes the process of implementing IMRT for localized prostate cancer in a radiation therapy department. In our experience, IMRT implementation requires careful planning due to the need to simultaneously implement specialized software, multifaceted QA programs, and training of the multidisciplinary team. Establishing standardized protocols and ensuring close collaboration between a multidisciplinary team is challenging but essential.

[The bacillus Calmette-Guérin as immunomodulator in bladder cancer]. / Il bacilo de Calmette-Guérin como inmunomodulador en el cáncer de vejiga.

The bacillus Calmette-Guérin (BCG) is regarded as the most successful immunotherapy against superficial bladder carcinoma recurrences to date. BCG intravesical therapy for superficial bladder cancer has shown its efficacy and advantage over classical therapeutic strategies. This efficacy is based on complex and long lasting immune activation. The initial step is the binding of mycobacteria to the urothelial lining, which depends on the interaction of a fibronectin attachment protein on the bacteria surface with fibronectin in the bladder wall. Granulocytes and other immunocompetent mononuclear cells became attracted to the bladder wall and a cascade of proinflammatory cytokines sustains the immune response. In the bladder wall a largely TH1 based cytokine milieu and granuloma-like cellular foci are established. Within this scenario, the most important effector mechanisms might be the direct antitumor activity of interferons and the cytotoxic activity of NK cells. Current treatment consists of an induction phase of 6 weeks and a maintenance dose schedule of 3 weeks every three months up to 36. The majority of patients present adverse events related to dose administration due to bladder inflammatory response and on only a few occasions, there are mayor complications like granulomatous prostatitis. Among all the neoplasms only in superficial bladder cancer the BCG is proved to be effective.

El bacilo de Calmette-Guérin como inmunomodulador en el cáncer de vejiga / The bacillus Calmette-Guérin as immunomodulator in bladder cancer

The bacillus Calmette-Guérin (BCG) is regarded as the most successful immunotherapy against superficial bladder carcinoma recurrences to date. BCG intravesical therapy for superficial bladder cancer has shown its efficacy and advantage over classical therapeutic strategies. This efficacy is based on complex and long lasting immune activation. The initial step is the binding of mycobacteria to the urothelial lining, which depends on the interaction of a fibronectin attachment protein on the bacteria surface with fibronectin in the bladder wall. Granulocytes and other immunocompetent mononuclear cells became attracted to the bladder wall and a cascade of proinflammatory cytokines sustains the immune response. In the bladder wall a largely TH1 based cytokine milieu and granuloma-like cellular foci are established. Within this scenario, the most important effector mechanisms might be the direct antitumor activity of interferons and the cytotoxic activity of NK cells. Current treatment consists of an induction phase of 6 weeks and a maintenance dose schedule of 3 weeks every three months up to 36. The majority of patients present adverse events related to dose administration due to bladder inflammatory response and on only a few ocassions, there are mayor complications like granulomatous prostatitis. Among all the neoplasms only in superficial bladder cancer the BCG is proved to be effective.

El bacilo de Calmette-Guérin (BCG) es considerado como la inmunoterapia más exitosa en contra del carcinoma de vejiga superficial recidivante hasta la fecha. La terapia intravesical con el BCG para el cáncer superficial de vejiga ha mostrado su eficacia y ventaja sobre otras estrategias terapéuticas; esta eficacia está basada en una compleja y larga duración de la activación inmunológica. El paso inicial es la unión de la micobacteria al urotelio, la cual depende de la interacción con la fibronectina de la bacteria con la fibronectina del urotelio. Los granulocitos y otras células mononucleares inmunocompetentes son atraídos hacia la pared vesical, así activando una cascada inmunológica a través de secreción de diversas citocinas, quienes estimulan a las células asesinas naturales (NK) activadas por el BCG, las cuales son capaces de diferenciar células neoplásicas y del epitelio urinario normal. En la pared vesical se encuentra un medio ambiente de citocinas principalmente del tipo TH1 y se forman focos celulares similares a granulomas. Dentro de este escenario los mecanismos efectores más importantes parecen ser la actividad antitumoral directa de los interferones y la actividad citotóxicas de las células NK. El tratamiento actual consiste en la administración intravesical del bacilo en una primera fase de inducción de seis semanas y posteriormente dosis de mantenimiento cada tres meses hasta los 36 meses. La mayoría de los pacientes presentan efectos adversos locales secundarios a la reacción inflamatoria y en un porcentaje muy pequeño se presentan complicaciones mayores como prostatitis y orquiepididimitis granulomatosa. De entre todas estas neoplasias sólo en el cáncer superficial de vejiga se han demostrado resultados satisfactorios con el empleo del BCG.