Caracterización epidemiológica del cáncer de mama / Epidemiological characterization of cancer breast

Con el objetivo de realizar la caracterización epidemiológica del cáncer de mama de las pacientes que asisten a la consulta externa de ginecología oncológica en el Instituto Guatemalteco de Seguridad Social (IGSS) de enero a marzo de 2,018, se realizó un estudio descriptivo transversal en 155 pacientes que acudieron a la clínica de mama del Hospital de Gineco Obstetricia del IGSS, con una media de edad de 62 años, el adenocarcinoma ductal infiltrante es el tipo histológico más frecuente en nuestra población tanto en edad reproductiva como en menopausia. Como factor protector el 69% dio lactancia materna. La etapa clínica más comúnmente diagnosticada es IIA. El Luminal A, el más frecuentemente diagnosticado por inmunohistoquímica, seguido del Luminal B y HER2neu. Se diagnostican pacientes mayormente en etapas clínicas tempranas (I y II).

In order to carry out the epidemiological characterization of breast cancer in patients attending the outpatient gynecology oncology consultation at the Guatemalan Social Security Institute (IGSS) from January to March 2018, a descriptive cross-sectional study was carried out in 155 patients who attended the breast clinic of the IGSS Obstetrics Gynecology Hospital, with a mean age of 62 years, infiltrating ductal adenocarcinoma is the most frequent histological type in our population both in reproductive age and in menopause. As a protective factor, 69% breastfed. The most diagnosed clinical stage is IIA. Luminal A, the most frequently diagnosed by immunohistochemistry, followed by Luminal B and HER2neu. Patients are diagnosed mostly in early clinical stages (I and II).

Expresión tumoral de BRCA1 y resultados clínicos en pacientes uruguayas diagnosticadas de cáncer de mama antes de los 40 años / BRCA1 tumor expression and clinical results in uruguayan patients diagnosed with breast cancer before the age of 40 years old / Expressão tumoral de BRCA1 e resultados clínicos em pacientes uruguaias com diagnóstico de câncer de mama antes dos 40 anos

Resumen: Las mutaciones de BRCA1 son raras en el cáncer de mama (CM) esporádico; sin embargo, su expresión a nivel tumoral se encuentra disminuida o ausente en 30%-50% de los casos. Objetivo: valorar la expresión tumoral de BRCA1 por inmunohistoquímica (IHQ) en mujeres uruguayas diagnosticadas de CM antes de los 40 años. Material y método: se incluyeron pacientes diagnosticadas de CM antes de los 40 años. Se utilizaron los anticuerpos monoclonales anti-BRCA1 MS110 contra el extremo N-terminal y GLK-2 contra el extremo C-terminal. Se calculó la sobrevida global (SVG) y la sobrevida libre de enfermedad (SVLE), para la construcción de las curvas se utilizó el método de Kaplan-Meier y la diferencia de sobrevida se evaluó mediante el test de log rank. Resultados: se incluyeron 40 pacientes, la SVG y la SVLE a cinco años fueron de 73% y 60% respectivamente. La expresión de BRCA1 mediante GLK-2 fue <10% en 16 de las 40 pacientes (40%). La SVG y la SVLE a cinco años para las pacientes con expresión <10% fue de 56% vs 85% para las pacientes con expresión >10% (p=0,015) y de 40% vs 72% (p=0,034) respectivamente. La expresión de BRCA1 mediante MS110 fue <10% en 11 de las 40 pacientes (27,5%). No se encontraron diferencias en la SVG ni en la SVLE a cinco años con este marcador. Conclusión: la pérdida de la expresión tumoral de BRCA1 determinada mediante GLK-2 se encontró en el 40% de las pacientes incluidas y se asoció a una menor SVG y SVLE, por lo que podría tener un valor pronóstico desfavorable en estas pacientes.

Summary: BRCA1 mutations are rare in sporadic breast cancer (CM), however their expression at the tumor level is diminished or absent in 30-50% of cases. Objective: to assess the tumor expression of BRCA1 using immunohistochemistry (IHC) in Uruguayan women diagnosed with BC before the age of 40 years. Material and methods: patients diagnosed with BC before the age of 40 between. The antibodies used were anti BRCA1 MS110 monoclonal antibodies against the N-terminal end and GLK-2 against the C-terminal. Overall survival (OS) and disease free survival (DFS) were calculated; the curves were developed using the Kaplan-Meier method and the difference in survival was evaluated through the log rank test. Results: the average age of the 40 patients included was 36 years. The 5-year OS and DFS were 73% and 60% respectively. The expression of BRCA1 with GLK-2 was <10% in 16 of the 40 patients included (40%). The 5-year OS and DFS for patients with <10% expression was 56% vs. 85% for patients with >10% (p=0.015) and 40% vs. 72% (p = 0.034) respectively. The expression of BRCA1 by MS110 was <10% in 11 of the 40 patients included (27.5%). No differences were found in the 5-year OS or DFS based on the expression of this marker. Conclusion: The loss of BRCA1 expression using GLK-2, which suggests the presence of a truncated protein, was associated with a statistically significantly lower OS and DFS, that the decrease in the BRCA1 protein as determined by GLK2 has an unfavorable prognostic value for young patients with BC.

Resumo: As mutações de BRCA1 são raras no câncer de mama (CM) esporádico; no entanto sua expressão no nível tumoral está diminuída ou ausente em 30-50% dos casos. Objetivo: avaliar a expressão tumoral de BRCA1 por imuno-histoquímica (IHQ) em mulheres uruguaias com diagnóstico de CM antes dos 40 anos. Material e métodos: foram incluídas pacientes com diagnóstico de CM antes dos 40 anos. Foram utilizados anticorpos monoclonais anti BRCA1 MS110 contra o extremo N-terminal e GLK-2 contra o extremo C-terminal. A sobrevida global (SVG) e a sobrevida livre de enfermidade (SVLE) foram calculadas; o método de Kaplan-Meier foi utilizado para a construção das curvas e a diferença de sobrevida foi avaliada usando o teste de log-rank. Resultados: foram incluídas 40 pacientes; a SVG e a SVLE aos 5 anos foram 73% e 60% respectivamente. A expressão de BRCA1 mediante GLK-2 foi <10% em 16 das 40 pacientes (40 %). A SVG e a SVLE aos 5 anos para as pacientes com expressão £10% foi 56% vs. 85% para as pacientes com expressão >10% (p=0,015) e 40% vs. 72% (p=0,034) respectivamente. A expressão de BRCA1 mediante MS110 foi =10% em 11 das 40 pacientes (27,5%). Não foram encontradas diferenças na SVG nem na SVLE aos 5 anos com este marcador. Conclusão: foi encontrada perda da expressão tumoral de BRCA1 determinada por GLK-2 em 40% das pacientes incluídas e foi associada a uma menor SVG e SVLE, o que poderia ter um valor prognóstico desfavorável nestas pacientes.

Expresión de BRCA1 en lesiones benignas y malignas de la mama / BRCA1 expression in benign and malignant breast lesions

La mayor parte de los carcinomas de mama son cánceres esporádicos; sin embargo, existe una proporción, estimada entre el 5 y el 10%, en la cual aparece una predisposición hereditaria al cáncer, asociado principalmente a mutaciones germinales en los genes BRCA1 y BRCA2; tales mutaciones incrementan la predisposición para el desarrollo de la enfermedad durante el transcurso de la vida. El objetivo general de este trabajo fue valorar la expresión del gen BRCA1 por inmunohistoquímica (IHQ). El estudio se realizó en mujeres diagnosticadas con lesiones benignas o con carcinoma ductal infiltrante de mama en seguimiento en el Instituto de Oncología “Dr. Miguel Pérez Carreño” de Valencia, Venezuela. Se analizó la expresión de la proteína BRCA1 y los resultados obtenidos se compararon con la clasificación de las lesiones benignas propuesta por Dupont y Page y los subtipos moleculares intrínsecos definidos por IHQ. De este análisis se obtuvo que tanto en las lesiones no infiltrantes (proliferativas y carcinoma in situ), así como en los carcinomas infiltrantes, predominaron los casos con un marcaje nuclear de BRCA1 por IHQ ≤10%. Además, la relación de la expresión de BRCA1 con la media de la supervivencia global, obtuvo valor pronóstico desfavorable, cuando la expresión nuclear y citoplasmática de BRCA1 fue ≤10%, con p<0,05. Finalmente, en base a los resultados, se sugiere que en el algoritmo de abordaje de mujeres con riesgo de padecer cáncer de mama, se incluya la valoración de la expresión de BRCA1 por IHQ.

The majority of breast cancers are sporadic cancers; however, there is an estima¬ted proportion of 5% to 10%, where a hereditary predisposition appears, mainly associated with germline mutations in the BRCA1 and BRCA2 genes. Such mutations increase the predis-position to develop the disease during the course of life. The overall objective of this work was to evaluate the expression of the BRCA1 gene by immunohistochemistry (IHC). The study was conducted in women diagnosed with benign lesions or invasive breast ductal carcinoma in follow-up care at the Institute of Oncology “Dr. Miguel Perez Carreño” in Valencia, Venezuela. Expression of the BRCA1 protein was analyzed and the results were compared with the benign lesions classification given by DuPont and Page and the intrinsic molecular subtypes defined by IHC. From this analysis it was found that in both, non-infiltrative lesions (proliferative and carcinoma in situ), as well as in infiltrating carcinomas, predominated the cases with BRCA1 nuclear labeling by IHC (≤10 %). Furthermore, the relationship of expression of BRCA1 with the average overall survival, showed a poor prognostic value obtained when the nuclear and cytoplasmic expression of BRCA1 was ≤10%, with p<0.05. Finally, based on the results, it is suggested that the assessment of BRCA1 expression by IHC should be included in the approach algorithm of women at risk of developing breast cancer.

Analysis of BRCA1 involvement in breast cancer in Indian women.

The involvement of the familial breast-ovarian cancer gene (BRCA1) in the molecular pathogenesis of breast cancer among Indian women is unknown. We have used a set of microsatellite polymorphisms to examine the frequency of allele loss at the BRCA1 region on chromosome 17q21, in a panel of 80 human breast tumours. Tumour and blood leukocyte/normal tissue DNA from a series of 80 patients with primary breast cancer was screened by PCR-amplified microsatellite length polymorphisms to detect deletions at three polymorphic BRCA1 loci. PCR-allelotype was valuable in examining allele losses from archival and small tumour samples. Loss of alleles at BRCA1 in the patient set, confirmed a noteworthy role of this gene in the molecular patho-genesis of breast cancer and was in accordance with its well-documented tumour suppressive function.