Molecular Basis and Diagnostic Approach to Isolated and Syndromic Lateralized Overgrowth in Childhood.

OBJECTIVE: To demonstrate a high-yield molecular diagnostic workflow for lateralized overgrowth (LO), a congenital condition with abnormal enlargement of body parts, and to classify it by molecular genetics. STUDY DESIGN: We categorized 186 retrospective cases of LO diagnosed between 2003 and 2023 into suspected Beckwith-Wiedemann spectrum, PIK3CA-related overgrowth spectrum (PROS), vascular overgrowth, or isolated LO, based on initial clinical assessments, to determine the appropriate first-tier molecular tests and tissue for analysis. Patients underwent testing for 11p15 epigenetic abnormalities or somatic variants in genes related to PI3K/AKT/mTOR, vascular proliferation, and RAS-MAPK cascades using blood or skin DNA. For cases with negative initial tests, a sequential cascade molecular approach was employed to improve diagnostic yield. RESULTS: This approach led to a molecular diagnosis in 54% of cases, 89% of cases consistent with initial clinical suspicions, and 11% reclassified. Beckwith-Wiedemann spectrum was the most common cause, with 43% of cases exhibiting 11p15 abnormalities. PIK3CA-related overgrowth spectrum had the highest confirmation rate, with 74% of clinically diagnosed patients showing a PIK3CA variant. Vascular overgrowth demonstrated significant clinical overlap with other syndromes. A molecular diagnosis of isolated LO proved challenging, with only 21% of cases classifiable into a specific condition. CONCLUSIONS: LO is underdiagnosed from a molecular viewpoint and to date has had no diagnostic guidelines, which is crucial for addressing potential cancer predisposition, enabling precision medicine treatments, and guiding management. This study sheds light on the molecular etiology of LO, highlighting the importance of a tailored diagnostic approach and of selecting appropriate testing to achieve the highest diagnostic yield.

Prevalencia y análisis clinicopatológico de pacientes con mutación en el gen PIK3CA con cáncer de mama avanzado Rh+/Her2- en el Instituto Oncológico Nacional De Panamá

Antecedentes: La vía de señalización de la fosfoisitol 3-quinasa (PI3K), que promueve el crecimiento y el metabolismo de las células cancerosas, es la vía mutada con mayor frecuencia en el cáncer de mama y es asociada con quimio resistencia y mal pronóstico. En este estudio presentamos el primer análisis en población panameña y de la región, con ataciones precisas de la mutación PIK3CA, las características clinicopatológicas y pronóstico. Métodos: Estudio exploratorio, donde se recolectaron prospectivamente tumores de 74 pacientes con cáncer de mama metastásico RH+/Her2- del Instituto Oncológico Nacional entre 2022 y 2023. Se realizó un ensayo de PCR en tiempo real para análisis de mutación en ADN extraído del material tumoral fijado en formalina e incluido en parafina para detectar mutaciones en los exones 1, 4, 7, 9 y 20 del gen PIK3CA. Resultados: La mediana de edad de las pacientes estudiadas fue 59 años. La mutación en PIK3CA se encontró en 33.8% (25/74) de pacientes con cáncer de mama, entre ellas 44% fueron mutaciones en el exón 20, 38% en el exón 9, 13% en el exón 4 y 5% en el exón 1. Se observó una correlación significativa entre la mutación y el  tener historia de cáncer en la familia (p= 0.005), y en pacientes postmepáusicas (P = 0.045).  encontramos asociación entre la mutación y el tipo histológico, grado, tamaño tumoral ni estatus axilar al momento del diagnóstico. La mediana de supervivencia libre de progresión  se alcanzó en ambos grupos y tampoco demostró una diferencia significativa. Conclusión: La prevalencia de la mutación es relativamente alta comparada con escenarios internacionales, puede ofrecer una ventaja para elegir las mejores opciones de tratamiento por lo que debe evaluarse de forma rutinaria durante las intervenciones clínicas. (provisto por Infomedic International)

Background: The phosphoisitol 3-kinase (PI3K) signaling pathway, which promotes cancer cell growth and metabolism, is the most frequently mutated pathway in breast cancer and is associated with chemoresistance and poor progsis. In this study we present the first analysis in Panamanian and regional population, with precise antations of the PIK3CA mutation, clinicopathological characteristics and progsis. Methods: Exploratory study, where tumors were prospectively collected from 74 patients with RH+/Her2- metastatic breast cancer from the Instituto Oncológico Nacional between 2022 and 2023. A real-time PCR assay for mutation analysis was performed on DNA extracted from formalin-fixed, paraffin-embedded tumor material to detect mutations in exons 1, 4, 7, 9 and 20 of the PIK3CA gene. Results: The median age of the patients studied was 59 years. The mutation in PIK3CA was found in 33.8% (25/74) of patients with breast cancer, among them 44% were mutations in exon 20, 38% in exon 9, 13% in exon 4 and 5% in exon 1. A significant correlation was observed between the mutation and having  history of cancer in the family (P = 0.005), and in postmepausal patients (P = 0.045). We found  association between the mutation and histologic type, grade, tumor size or axillary status at diagsis. Median progression-free survival was t reached in both groups and did t show a significant difference. Conclusion: The prevalence of the mutation is relatively high compared to international settings, it may offer an advantage in choosing the best treatment options and should be routinely evaluated during clinical interventions. (provided by Infomedic International)

Clínica, auxología y calidad de vida en cincuenta niños, niñas y adolescentes con síndromes de sobrecrecimiento corporal segmentario de un único centro / Clinical and auxological characteristics and quality of life of 50 children and adolescents with segmental overgrowth syndromes at a single center

Introducción. Los síndromes de sobrecrecimiento corporal segmentario son un grupo de enfermedades poco frecuentes caracterizadas por exceso de crecimiento en una o más partes del cuerpo relacionadas, en su mayoría, con mutaciones en mosaico en la vía de señalización AKT/PI3K/mTOR y RAS-MAPK. Nuestro objetivo fue analizar las características clínicas y auxológicas, y la calidad de vida relacionada a salud (CVRS) en este grupo de pacientes en un hospital de tercer nivel de atención. Población y métodos. Estudio transversal de una cohorte en seguimiento. Se analizaron edad, sexo, datos sociodemográficos, mediciones antropométricas del segmento afectado y del contralateral, complicaciones, tratamiento, calidad de vida (PedsQL4.0) y dolor. Se calcularon medidas centrales y de dispersión. Se realizó análisis univariado entre calidad de vida y variables incluidas. Resultados. Se incluyeron 50 pacientes, 29 varones. Mediana de edad 9,95 (r 1,44-17,81) años. El diagnóstico más frecuente fue síndrome de sobrecrecimiento relacionado a PIK3CA (PROS) (37/50). Mediana de número de segmentos afectados 2 (r: 1-7) por niño. Cuarenta casos presentaron malformación vascular; 20, capilar. El dolor (24/50) fue la complicación más frecuente. Treinta y un pacientes mostraron asimetría de longitud de miembros inferiores, < 5 cm. La estatura se ubicó entre los centilos 50 y 97 en la mayoría de los niños. Menor CVRS se observó en mujeres, en pacientes con malformación vascular compleja y necesidades básicas insatisfechas (NBI). Conclusiones. PROS fue el diagnóstico más frecuente. El dolor fue una complicación frecuente. La CVRS fue menor en mujeres, pacientes con malformación vascular combinada y NBI.

Introduction. Segmental overgrowth syndromes are a group of rare diseases characterized by overgrowth in one or more parts of the body, mostly related to mosaic mutations in the AKT/PI3K/mTOR and RASMAPK signaling pathway. Our objective was to analyze the clinical and auxological characteristics and health-related quality of life (HRQoL) in this group of patients at a tertiary care hospital. Population and methods. Cross-sectional study of a follow-up cohort. Age, sex, sociodemographic data, anthropometric measurements of the affected and contralateral segments, complications, treatment, quality of life (PedsQL 4.0), and pain were analyzed. Central and dispersion measures were estimated. A univariate analysis between the quality of life and study variables was done. Results. A total of 50 patients were included; 29 were males. Median age: 9.95 (r: 1.44­17.81) years. The most common diagnosis was PIK3CA-related overgrowth spectrum (PROS) (37/50). The median number of affected segments was 2 (r: 1­7) per patient. Vascular malformations were observed in 40, and capillary malformations, in 20 patients. Pain was the most common complication (24/50). An asymmetry of the lower extremities of < 5 cm was observed in 31 patients. In most children, height was between the 50th and 97th percentiles. A lower HRQoL was observed among girls, patients with complex vascular malformations, and those with unmet basic needs (UBNs). Conclusions. PROS was the most common diagnosis. Pain was the most common complication. HRQoL was lower among girls, patients with combined vascular malformations, and those with UBNs.

Clinical and auxological characteristics and quality of life of 50 children and adolescents with segmental overgrowth syndromes at a single center. / Clínica, auxología y calidad de vida en cincuenta niños, niñas y adolescentes con síndromes de sobrecrecimiento corporal segmentario de un único centro.

Introduction. Segmental overgrowth syndromes are a group of rare diseases characterized by overgrowth in one or more parts of the body, mostly related to mosaic mutations in the AKT/PI3K/mTOR and RAS- MAPK signaling pathway. Our objective was to analyze the clinical and auxological characteristics and health-related quality of life (HRQoL) in this group of patients at a tertiary care hospital. Population and methods. Cross-sectional study of a follow-up cohort. Age, sex, sociodemographic data, anthropometric measurements of the affected and contralateral segments, complications, treatment, quality of life (PedsQL 4.0), and pain were analyzed. Central and dispersion measures were estimated. A univariate analysis between the quality of life and study variables was done. Results. A total of 50 patients were included; 29 were males. Median age: 9.95 (r: 1.44-17.81) years. The most common diagnosis was PIK3CA-related overgrowth spectrum (PROS) (37/50). The median number of affected segments was 2 (r: 1-7) per patient. Vascular malformations were observed in 40, and capillary malformations, in 20 patients. Pain was the most common complication (24/50). An asymmetry of the lower extremities of < 5 cm was observed in 31 patients. In most children, height was between the 50th and 97th percentiles. A lower HRQoL was observed among girls, patients with complex vascular malformations, and those with unmet basic needs (UBNs). Conclusions. PROS was the most common diagnosis. Pain was the most common complication. HRQoL was lower among girls, patients with combined vascular malformations, and those with UBNs.

Introducción. Los síndromes de sobrecrecimiento corporal segmentario son un grupo de enfermedades poco frecuentes caracterizadas por exceso de crecimiento en una o más partes del cuerpo relacionadas, en su mayoría, con mutaciones en mosaico en la vía de señalización AKT/PI3K/mTOR y RAS-MAPK. Nuestro objetivo fue analizar las características clínicas y auxológicas, y la calidad de vida relacionada a salud (CVRS) en este grupo de pacientes en un hospital de tercer nivel de atención. Población y métodos. Estudio transversal de una cohorte en seguimiento. Se analizaron edad, sexo, datos sociodemográficos, mediciones antropométricas del segmento afectado y del contralateral, complicaciones, tratamiento, calidad de vida (PedsQL4.0) y dolor. Se calcularon medidas centrales y de dispersión. Se realizó análisis univariado entre calidad de vida y variables incluidas. Resultados. Se incluyeron 50 pacientes, 29 varones. Mediana de edad 9,95 (r 1,44-17,81) años. El diagnóstico más frecuente fue síndrome de sobrecrecimiento relacionado a PIK3CA (PROS) (37/50). Mediana de número de segmentos afectados 2 (r: 1-7) por niño. Cuarenta casos presentaron malformación vascular; 20, capilar. El dolor (24/50) fue la complicación más frecuente. Treinta y un pacientes mostraron asimetría de longitud de miembros inferiores, < 5 cm. La estatura se ubicó entre los centilos 50 y 97 en la mayoría de los niños. Menor CVRS se observó en mujeres, en pacientes con malformación vascular compleja y necesidades básicas insatisfechas (NBI). Conclusiones. PROS fue el diagnóstico más frecuente. El dolor fue una complicación frecuente. La CVRS fue menor en mujeres, pacientes con malformación vascular combinada y NBI.

Molecular Profile of Canine Hemangiosarcoma and Potential Novel Therapeutic Targets.

Canine hemangiosarcoma (HSA) is a relatively common neoplasia, occurring mainly in the skin, spleen, liver and right atrium. Despite the numerous studies investigating the treatment of canine HSA, no significant improvement in survival has been achieved in the last 20 years. Advancements in genetic and molecular profiling presented molecular similarities between canine HSA and human angiosarcoma. It could therefore serve as a valuable model for investigating new and more effective treatments in people and dogs. The most common genetic abnormalities in canine HSA have been found in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and neuroblastoma RAS viral oncogene homolog (NRAS) pathways. Mutations are also found in tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN) and cyclin dependent kinase inhibitor 2A (CDKN2A). Known abnormal protein expression could be exploited to trial new target treatments that could be beneficial for both canine and human patients. Despite the high expression of vascular endothelial growth factor (VEGF) and its receptor (VEGFR), no correlation with overall survival time has ever been found. In this review, we explore the most recent developments in molecular profiling in canine HSA and discuss their possible applications in the prognosis and treatment of this fatal disease.

Vascular Anomalies Care in the United States: A Cross-Sectional National Survey.

OBJECTIVE: To characterize the current distribution, composition, and practice patterns of multidisciplinary vascular anomalies (VAs) teams in the US. STUDY DESIGN: This is a cross-sectional survey of children's hospitals in the US offering VAs care. We approached 142 children's hospitals that provided care for VAs via email. The survey evaluated VA clinic location, medical staffing, research participation, and treatments offered. The survey was administered between October 2021 and July 2022. RESULTS: Participants from 95 eligible hospitals responded to the survey (response rate = 67%). Large areas of the Midwest and Northwest US had no available multidisciplinary VA teams or clinics. Most respondents worked at academic centers (89%), with 66% at a freestanding children's hospital, and 56% reported having a multidisciplinary clinic. Most common physician participants in clinic included hematology-oncology (91%), interventional radiology (87%), dermatology (85%), plastic surgery (81%), and otolaryngology (74%). Only 38% of programs included medical geneticists. Smaller hospitals had fewer medical and ancillary staff and offered fewer therapeutic options. Research was available at most larger institutions (69%) but less commonly at smaller hospitals (34%). CONCLUSIONS: Major portions of the US lack multidisciplinary VA care. Furthermore, VA programs vary in composition and geneticists are absent from the majority of programs. These findings should inform efforts to address disparate access and develop standards of care for multidisciplinary VA care in the US.

Genetic and epigenetic characteristics of patients with colorectal cancer from Uruguay.

Colorectal cancer (CRC), the 3rd most frequent cancer worldwide, affects both men and women. This pathology arises from the progressive accumulation of genetic and epigenetic alterations. In this study, KRAS, NRAS, PIK3CA, and BRAF gene mutations, mismatch repair (MMR) genes methylation profile, microsatellite instability (MSI) and CpG Island Methylator Phenotype (CIMP) status were assessed. The associations of these molecular features with clinicopathological data were also investigated. A hundred and eight unselected CRC samples and their histological and clinical data, were gathered between 2017 and 2020. The prevalence of KRAS, NRAS and BRAF gene mutations was similar to that described in other populations. 28.7% of tumors were KRAS-mutated, mostly in men, distal location, with a CIMP-negative status. BRAFV600E frequency was 6.5% and associated with MSI (p = 0.048), MLH1-methylated (p < 0.001) and CIMP-High (p < 0.001) status. We also confirmed that BRAFV600E tumors were more prevalent in older women and proximal location. A striking different result was the lack of most common variants in the PIK3CA gene. A complete absence of PIK3CA-mutated tumors in a population has not been previously reported. Among MMR genes, the only with an aberrant methylation pattern was MLH1 gene. Its frequency was 9.25%, lower than previously reported. Methylated tumors were most frequent in patients older than 70 years old and proximal tumor location. Finally, CIMP-High status was mainly observed in moderately differentiated tumors with a rate of 15.7%. Our findings were consistent with previous reports in other populations, but also showed some features unique to our cohort. This study is the first to report the analysis of a large number molecular biomarkers of CRC in Uruguay and one of the few performed in Latin-America.

Chip-based digital Polymerase Chain Reaction as quantitative technique for the detection of PIK3CA mutations in breast cancer patients.

Background: PIK3CA is a gene frequently mutated in breast cancer. With the FDA approval of alpelisib, the evaluation of PIK3CA for activating mutations is becoming routinely. Novel platforms for gene analysis as digital PCR (dPCR) are emerging as a potential replacement for the traditional Sanger sequencing. However, there are still few studies on chip-based dPCR to detect mutations in tumor samples. Thus, this cross-sectional study aimed to assess the sensibility of a chip-based dPCR to detect and quantify PIK3CA mutations and compare its performance with Sanger sequencing. Materials and Methods: Tumor samples from 57 breast cancer patients (22 pre-treatment samples, 32 tumors after neoadjuvant chemotherapy, and three lymph nodes) were collected and analyzed by Sanger sequencing and dPCR for the three PIK3CA most relevant mutations (p.E545K, p. H1047R, and p. H1047L). Digital PCR sensitivity, specificity, and overall performance were estimated by contingency tables, receptor operator characteristic (ROC), and area under the curve (AUC). Association of PIK3CA mutations with clinicopathological variables was conducted. Results: Sanger sequencing identified PIK3CA mutations in six patients (10.5%), two with p. H1047R, and four with p. E545K. Digital PCR confirmed those mutations and identified 19 additional patients with at least one mutation. Comparison between dPCR and Sanger sequencing showed a sensitivity of 100% (95% CI 53-100%), and a specificity of 84.2% (95% CI 83-84.2%). Besides, p. H1047R mutation detected by dPCR showed a significant association with breast cancer phenotype (p = 0.019) and lymphatic nodes infiltration (p = 0.046). Conclusions: Digital PCR showed a high sensitivity to detect mutations in tumor samples and it might be capable to detect low-rate mutations and tumor subpopulations not detected by Sanger sequencing.

Association between PIK3CA Mutations in Blood and Tumor-Infiltrating Lymphocytes in Peruvian Breast Cancer Patients.

OBJECTIVE: To evaluate the relationship between circulating tumor DNA (ctDNA) presence and tumor features including tumor-infiltrating lymphocyte (TIL) levels in Peruvian breast cancer patients. MATERIALS AND METHODS: This was a prospective study conducted at the Instituto Nacional de Enfemedades Neoplasicas, Peru. We evaluated level of TIL and PIK3CA mutations in ctDNA. Clinical characteristics, including outcome data, were collected from the patient file. Survival was calculated from the date of blood sample drawn to the event time. Data collected were analyzed using SPSS software version 25. RESULTS: We analyzed plasma samples from 183 breast cancer patients. most cases were of Luminal-B (44.8%) phenotype and stage II (41.5%), and median stromal TIL was 30%. PIK3CA mutation in ctDNA was detected in 35% cases (most with E545K) and was associated with lower TIL level (p=0.04). PIK3CA in ctDNA tended to be associated with advanced stages (p=0.09) in the whole series and with higher recurrence rates (p=0.053) in the non-metastatic setting. Patients with presence of PIK3CA in ctDNA tended to have shorter survival (p=0.083). CONCLUSION: Presence of PIK3CA mutation in ctDNA was frequently found in our Peruvian breast cancer series, was associated with lower TIL levels and tended to predict poor outcomes.

A biomarker study in Peruvian males with breast cancer.

BACKGROUND: Breast cancer (BC) frequency in males is extremely low and tumor features vary from its female counterpart. Breast cancer clinical and pathological features differ by race in women. Tumor infiltrating lymphocyte (TIL) levels, mismatch repair (MMR) protein loss, androgen receptor (AR) expression, and PIK3CA gene mutations are predictive biomarkers of response to biological therapy in female BC. There is limited information about clinical and pathological features as well as predictive biomarkers in males of non-Caucasian races with BC. AIM: To investigate clinicopathological features and biomarkers of BC tumors in males and their prognostic value in Peruvian population. METHODS: This study looked at a single-institution series of 54 Peruvian males with invasive BC who were diagnosed from Jan 2004 to June 2018. Standard pathological features, TIL levels, MMR proteins, AR immunohistochemistry staining, and PIK3CA gene mutations were prospectively evaluated in cases with available paraffin material. Percentage of AR and estrogen receptor (ER) positive cells was additionally calculated by software after slide scanning. Statistical analyses included association tests, intraclass correlation test and Kaplan Meier overall survival curves. RESULTS: The median age was 63 years and most cases were ER-positive (85.7%), HER2 negative (87.2%), Luminal-A phenotype (60%) and clinical stage II (41.5%) among our male breast tumors. Median TIL was 10% and higher levels tended to be associated with Luminal-B phenotype and higher grade. AR-positive was found in 85.3% and was correlated with ER (intraclass index of 0.835, P < 0.001). Loss of MMR proteins was found in 15.4% and PIK3CA mutation (H1047R) in 14.3% (belonged to the Luminal-A phenotype). Loss of MMR proteins was associated with AR-negative (P = 0.018) but not with ER (P = 0.43) or TIL (P = 0.84). Early stages (P < 0.001) and lower grade (P = 0.006) were associated with longer overall survival. ER status, phenotype, AR status, TIL level, MMR protein loss nor PIK3CA mutation was not associated with survival (P > 0.05). CONCLUSION: Male BC is usually ER and AR positive, and Luminal-A. MMR loss and PIK3CA mutations are infrequent. Stage and grade predicted overall survival in our South American country population.

PIK3CA mutation in non-metastatic triple-negative breast cancer as a potential biomarker of early relapse: A case report.

BACKGROUND: Currently, the detection of PIK3CA mutations is of special interest in personalized medicine because it is frequently found in triple-negative breast cancer (TNBC). The PI3KCA mutation is an independent negative prognostic factor for survival in metastatic breast cancer, and its prognostic value in liquid biopsy as a biomarker of treatment and early relapse is under investigation, both for metastatic disease and neoadjuvant scenario with curative intent. CASE SUMMARY: A 54-year-old female patient with TNBC clinical stage IIIA, who, after receiving neoadjuvant chemotherapy (based on anthracyclines and taxanes), surgery, radiotherapy, and adjuvant capecitabine, was detected with a PI3KCA mutation in tissue and peripheral blood (ctDNA in liquid biopsy). After 10 mo, the patient had disease relapse of left cervical node disease. CONCLUSION: The detection of PIK3CA mutation in TNBC after neoadjuvant treatment might be associated with early relapse or rapid disease progression.

Prognostic value of molecular biomarkers in patients with metastatic colorectal cancer: a real-world study.

PURPOSE: Outcomes for patients with metastatic colorectal cancer (mCRC) have been improved by the identification of biomarkers predictive and prognostic of clinical outcome. The present retrospective analysis was undertaken to assess the utility of key biomarkers and clinical parameters in predicting outcomes in Spanish patients with mCRC. METHODS: We retrospectively analyzed tumor samples from a series of patients aged > 18 years with mCRC who were treated at the Hospital General Universitario Gregorio Marañón Spain. Real-time polymerase chain reaction was used to detect KRAS, NRAS, BRAF, and PIK3CA mutations. The key outcome of interest was overall survival (OS). Survival curves were estimated using the Kaplan-Meier method and stratified by the variables of greatest clinical interest. Differences were tested using the log-rank test. RESULTS: Median OS in the overall population was 24.4 months. Triple WT patients (WT KRAS, NRAS, and BRAF) and quadruple WT patients (WT KRAS, NRAS, BRAF, and PIK3CA) had significantly better OS than those who did not have triple or quadruple WT tumors. OS was significantly better in patients with left- vs. right-sided tumors, patients with resected primary tumors and metastases vs. those without resection, and patients with isolated hepatic and isolated pulmonary metastases. CONCLUSIONS: This retrospective, observational study has confirmed the prognostic value of the location and resection status of the primary tumor and metastases in Spanish patients with mCRC. Triple WT status, in particular, was prognostic in this patient population, with PIK3CA adding to the prognostic value in the quadruple WT population.

Germline and Somatic mutations in postmenopausal breast cancer patients

OBJECTIVES: In breast cancer (BC) patients, the frequency of germline BRCA mutations (gBRCA) may vary according to the ethnic background, age, and family history of cancer. Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is the second most common somatic mutated gene in BC; however, the association of mutations in both genes with cancer has not been thoroughly investigated. Thus, our aims were to investigate gBRCA mutation frequency in a cohort of postmenopausal Brazilian BC patients and the association of gBRCA1/BRCA2 and PIK3CA somatic mutations. METHODS: Forty-nine postmenopausal (>55 years) and forty-one young (≤35 years) BC patients were included in this study. The postmenopausal group included patients who reported a positive family history of cancer. For these patients, gBRCA1/BRCA2 were sequenced using next-generation sequencing (NGS) or Sanger sequencing. Data for gBRCA in young patients were already available from a previous study. DNA from formalin-fixed, paraffin-embedded (FFPE) tumors was obtained from 27 postmenopausal and 41 young patients for analyzing exons 9 and 20 of PIK3CA. The association between gBRCA1/BRCA2 and somatic mutations in PIK3CA was investigated. RESULTS: The overall frequency of gBRCA1/BRCA2 among the 49 postmenopausal patients was 10.2%. The frequencies of somatic mutations in PIK3CA in the postmenopausal and young patients were 37% and 17%, respectively (ns). The most common PIK3CA mutation was found to be E454A. Nonsense and frameshift mutations, which may counteract the oncogenic potential of PIK3CA were also detected. Regardless of age, 25% of BRCA1/BRCA2 mutation carriers and non-carriers , each, had PIK3CA somatic mutations. CONCLUSIONS: Data obtained indicate that BRCA1/BRCA2 gene testing may be considered for postmenopausal patients with BC who have a family history of cancer. Although some of them are not considered pathogenic, somatic variants of PIK3CA are frequently observed in BC patients, especially in postmenopausal patients.

Genetic alterations of triple negative breast cancer (TNBC) in women from Northeastern Mexico.

Triple negative breast cancer (TNBC) is a subtype of breast cancer of heterogeneous nature that is negative for estrogen receptor (ER), progesterone receptor (PR) and growth factor human epidermal 2 (HER2) following immunohistochemical analysis. TNBC is frequently characterized by relapse and reduced survival. To date, there is no targeted therapy for this type of cancer. Chemotherapy, radiotherapy, and surgery remain as the standard treatments options. The lack of a target therapy and the heterogeneity of TNBC highlight the need to seek new therapeutic options. In this study, fresh tissue samples of TNBC were analyzed with a panel of 48 driver genes (212 amplicons) that are likely to be therapeutic targets. We found intron variants, missense, stop gained and splicing variants in TP53, PIK3CA and FLT3 genes. Interestingly, all the analyzed samples had at least two variants in the TP53 gene, one being a drug response variant, rs1042522, found in 94% of our samples. We also found seven additional variants not previously reported in the TP53 gene, to the best of our knowledge, with probable deleterious characteristics of the tumor suppressor gene. We found four genetic variants in the PIK3CA gene, including two missense variants. The rs2491231 variant in the FLT3 gene was identified in 84% (16/19) of the samples, which not yet reported for TNBC, to the best of our knowledge. In conclusion, genetic variants in TP53 were found in all TNBC tumors, with rs1042522 being the most frequent (94% of TNBC biopsies), which had not been previously reported in TNBC. Also, we found two missense variants in the PIK3CA gene. These results justify the validation of these genetic variants in a large cohort, as well as the extensive study of their impact on the prognosis and therapy management of TBNC.

Impact of Ethnicity on Somatic Mutation Rates of Pancreatic Adenocarcinoma.

BACKGROUND/AIM: Ethnicity has an effect on survival in patients with pancreatic adenocarcinoma (PDAC), which may be reflected in the rate of somatic driver mutations. The Brazilian population represents au extensive interethnic admixture and little is known about the spectrum and rates of somatic driver mutations in Brazilian PDAC cases. MATERIALS AND METHODS: Direct sequencing of six genes in 23 PDAC cases was performed and the ancestry of patients was determined using a validated panel of ancestry-informative insertion/deletion DNA polymorphisms. RESULTS: KRAS proto-oncogene (KRAS) was the most commonly mutated gene (60%). A novel putatively pathogenic mutation in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (c.2948T>A; p.M983K) was identified. Mutations in epidermal growth factor receptor (EGFR) (4%), PIK3CA (4%), cyclin-dependent kinase inhibitor 2A (CDKN2A) (4%) and TP53 (8%) were noted, in rates that are less frequent than those reported for other populations. Mutations of B-Raf proto-oncogene, serine/threonine kinase (BRAF) were not present. All individuals with high African ancestral component (allelic frequency, >0.45) exhibited KRAS mutations. CONCLUSION: Our results highlight the importance of the effect of ethnicity on somatic mutations in Brazilian patients with PDAC.

EGFR pathway subgroups in Chilean colorectal cancer patients, detected by mutational and expression profiles, associated to different clinicopathological features.

Colorectal cancer is a multistep process affecting several signaling pathways including EGFR (epidermal growth factor receptor), a therapeutic target for metastatic disease. Our aim was to characterize the mutational and expression profiles of the EGFR pathway in colorectal tumors and to integrate these results according to five previously defined groups. We screened seven genes for mutations ( KRAS-BRAF-PIK3CA-PIK3R1-AKT1-MAP2K1-PTEN) and six proteins (EGFR-p110α-p85α-PTEN-phosphoAKT-phosphoMEK1) by immunohistochemistry, PTEN deletion, and MSI. At least one mutated gene was observed in 68% of tumors ( KRAS 45%, PIK3CA 21%, BRAF 14%, and PTEN 7%). PTEN deletion was observed in 10.7% of tumors and 19.6% were MSI-High. In all, 54% of tumors showed a high EGFR expression, 48% p110α, 4.4% phosphoAKT, and 22% phosphoMEK1; and 43% showed low PTEN expression and 22% p85α. In total, five groups of tumors were defined based on MSI, BRAF, and KRAS mutations. Three groups gather mainly early-stage tumors, whereas a fourth group is mostly conformed by advanced tumors. We described here that 71.4% of tumors from one group have a mutated PI3K/PTEN pathway, in comparison to other groups having 32%, 27%, and 25%. In addition, the five groups are differentiated by molecular features such as EGFR, p85α, p110α, and PTEN, showing variable expression among tumor groups. In conclusion, alterations on the EGFR pathway were found in a high percentage of colorectal cancer patients. Using the integration of diverse molecular markers, we ratified previous classification in an ethnic group having relevant genetic differences and living in a different environmental background, adding complementary molecular targets related to therapy.

Breast Tumor Resembling Tall Cell Variant of Papillary Thyroid Carcinoma: A Solid Papillary Neoplasm With Characteristic Immunohistochemical Profile and Few Recurrent Mutations.

OBJECTIVES: Breast tumor resembling tall cell variant of papillary thyroid carcinoma (BTRPTC) is a rare breast lesion that is unrelated to thyroid carcinoma. Morphologically, it shows a solid papillary lesion with bland cytology, eosinophilic/amphophilic secretions, nuclear grooves, reversal of nuclear polarity (recently described), and nuclear inclusions. Clinical course is often uneventful with few exceptions reported in the literature. Herein, we report three additional cases. METHODS: Immunohistochemical staining and next-generation sequencing was performed on all three cases. RESULTS: The lesional cells on all cases were positive for cytokeratin 5 and S100, with weak expression/lack of estrogen receptor. No staining was observed for myoepithelial markers (p63 and myosin heavy chain) around the lesion. IDH2 mutations were identified in two cases at nucleotide 172 (cases 1 and 3). ATM gene mutation was identified in cases 2 and 3 and PIK3CA mutation in case 3. All patients are currently without disease. CONCLUSIONS: BTRPTC is a slow-growing neoplastic lesion that needs to be distinguished from other papillary lesions for optimizing therapy.

DMBA induced mouse mammary tumors display high incidence of activating Pik3caH1047 and loss of function Pten mutations.

Controversy always existed on the utility of chemically induced mouse mammary carcinogenesis models as valid equivalents for the study of human breast cancer. Here, we performed whole exome and RNA sequencing on long latency mammary tumors (218 ± 27 days) induced by the carcinogen 7,12-Dimethylbenzathracene (DMBA) and short latency tumors (65 ± 11 days) induced by the progestin Medroxyprogesterone Acetate (MPA) plus DMBA in CD2F1 mice. Long latency tumors displayed a high frequency of Pi3kca and/or Pten mutations detected in 11 of 13 (85%) long latency cases (14/22, 64% overall). Eighty-two percent (9/11) of tumors carried the Pik3ca H1047L/R hot-spot mutation, as frequently found in human breast cancer. These tumors were luminal-like and mostly ER/PR+, as in humans. Transcriptome profiling indicated a significant activation of the PI3K-Akt pathway (p=3.82e-6). On the other hand MPA+DMBA induced short latency tumors displayed mutations in cancer drivers not commonly found mutated in human breast cancer (e.g. Hras and Apc). These tumors were mostly basal-like and MPA exposure led to Rankl overexpression (60 fold induction) and immunosuppressive gene expression signatures. In summary, long latency DMBA induced mouse mammary tumors reproduce the molecular profile of human luminal breast carcinomas representing an excellent preclinical model for the testing of PIK3CA/Akt/mTOR pathway inhibitory therapies and a good platform for the developing of additional preclinical tools such as syngeneic transplants in immunocompetent hosts.

Análisis molecular del cáncer de colon esporádico / Molecular analysis of sporadic colon cancer

Background: In Chile, colorectal cancer (CRC) is often diagnosed in late stages. Thus, surgical treatment must be complemented with chemotherapy. KRAS mutations and microsatellite instability have been detected in these tumors. However, the response to treatment in patients without KRAS mutations varies and requires a better understanding. Aim: To determine the frequency and distribution of somatic point mutations in KRAS, BRAF and PIK3CA genes and microsatellite instability status (MSI) in patients with colon cancer (CC). Material and Methods: A prospective observational study of patients undergoing surgery for colon cancer. Tumor-derived DNA was analyzed by polymerase chain reaction (PCR) for the most frequent mutations of KRAS, BRAF and PIK3CA. PCR was also used to analyze MSI. Results: Fifty-eight patients with sporadic CC were analyzed, 16 showed KRAS mutations (G12R, G12D, G12V, G13D) and out of the 42 patients that did not show any mutation, 10 had mutations in BRAF (V600E) and PIK3CA (E542K, E545D, E545K, Q546E, H1047R). BRAF mutations alone or in combination with PIK3CA mutations were observed in 27% of high MSI tumors and in 2% of tumors without instability (p < 0.049). A higher percentage of high MSI tumors were located in the right colon (p < 0.001), and showed BRAF mutation (p < 0.020). Conclusions: The highest percentage of high MSI and BRAF mutations was observed in the right colon. Therefore, this study suggests the presence of different molecular features between right and left colon tumors that should be considered when defining the therapeutic management.

PIK3CA mutations in Peruvian patients with HER2-amplified and triple negative non-metastatic breast cancers.

PURPOSE: To determine the frequency of PIK3CA mutations in a Peruvian cohort with HER2-amplified and triple negative breast cancers (TNBC). METHODS: We analyzed two cohorts of 134 primary non-metastatic breast cancer patients from Peru. Cohorts consisted of 51 hormone receptors (+)/HER2-amplified breast tumor patients surgically resected as first treatment included in the ALTTO trial (ALTTO cohort) and 81 TNBC patients with residual disease after neoadjuvant treatment (neoadjuvant cohort). Genomic DNA was extracted from paraffin-embedded tumor samples. Samples from the ALTTO and neoadjuvant cohorts were taken at biopsies and from residual tumors, respectively. PIK3CA mutations were detected by sequencing DNA fragments obtained by PCR amplification of exons and their flanking introns. All of the detected PIK3CA mutations were confirmed in a second independent run of sample testing. RESULTS: PIK3CA mutations were present in 21/134 cases (15.7%). Mutations in exon 9 and 20 were present in 10/134 (7.5%) and 11/134 (8.2%), respectively. No cases had mutations in both exons. Mutations in exon 9 consisted of E545A (seven cases), E545K (two cases) and E545Q (one case); while in exon 20, mutations consisted of H1047R (10 cases) and H1047L (one case). Compared to TNBC patients, HER2-amplified patients were more likely to have PIK3CA mutated (23% vs 9.6%; P=0.034). There were no associations between mutational status of PIK3CA with estrogen receptor status (P=0.731), progesterone receptor status (P=0.921), age (P=0.646), nodal status (P=0.240) or histological grade (P=1.00). No significant associations were found between PIK3CA mutational status and clinicopathological features. CONCLUSIONS: We found a similar frequency of PIK3CA mutations to that reported in other series. Although we did not include HR+/HER2 patients, those with HER2-amplified tumors were more likely to present PIK3CA mutations compared to patients with triple negative tumors.