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.

Angiomatosis of the breast in a male child. A case report with immunohistochemical analysis

Angiomatosis is a benign vascular lesion that has been described rarely in the breast. We describe a case in a seven-year-old boy of African descent who presented with progressively increasing, unilateral breast enlargement, the first such report in a male child. The patient underwent excisional biopsy of the breast mass followed by mastectomy. Pathologic examination revealed a diffuse proliferation of variably-sized, thin-walled vascular channels lined by flattened endothelium that showed negative immunohistochemical staining for von Willebrand factor, factor VIII-related antigen, CD34 and S-100 protein. There is no evidence of recurrence after 24 months of follow-up

Immunocytochemical detection of prolactin binding sites in fine needle aspiration smears of breast lesions.

Specific prolactin (PRL) binding sites were demonstrated in the fine needle aspiration cytology (FNAC) specimens from 68 patients with benign and malignant diseases of the breast using highly sensitive technique of DNP hapten sandwich staining procedure and antibody against human PRL. In 16 patients, immunocytochemical staining was also carried out on paraffin embedded sections of corresponding lesions. FNAC specimens included 52 neoplasms and 16 non-proliferative and proliferative benign breast disease. The reaction varied in different lesions, being maximum (72%) in malignant tumours and 60 per cent in benign tumours. However, benign breast disease showed a reaction that varied with the lesion. The technique was found to be simple, sensitive and economical for demonstrating specific PRL binding sites in cytology specimens of breast lesions.