Breast Cancer Molecular Subtypes Among Moroccan Women

Abstract

Introduction: Breast cancer remains despite the therapeutic progress, the leading cause of death by cancer among women. It represents a group of very heterogeneous clinical, histopathological and molecular diseases. Molecular heterogeneity has been demonstrated by genomic analysis, even for similar histology cancers. Four subgroups of breast carcinomas are distinguished: Luminal A, Luminal B, HER2 over expression and Basal - like. The Immuno-histo-chemical analysis useip (estrogen receptors) RE, the PR (progesterone receptors), the ((Human Epidermal Growth Factor Receptor-2), the Ki67 (proliferation marker) HER2, CK5/6) has shown a subdivision into subgroups similar to those found by genomic analysis. These subgroups are different from the point of view of clinical course and response to adjuvant treatment. Objectives: The aim of this work is to study the molecular profile of the breast cancers by immunostaining on Moroccan series to a classification with a prognostic value allowing a treatment tailored to each group of patients. Furthermore, the molecular subgroups were correlated to other clinical and histological factors. Material and methods: It is a prospective study of the laboratory of Anatomy and Pathologic cytology of the children's Hospital, the service I of the maternity hospital in Rabat and in cooperation with the United Nations Centre of pathological anatomy. To do this, 88 cases of breast cancer together were diagnosed between January 1, 2010 and December 31, 2014, taking a period of five years. All tissue samples made subject study of Immuno-histo-chemistry with the following markers: RE, PR, HER2 and Ki67. Only negative triple cases (HR and HER2 negative) benefited from an additional marking with CK5/6 and EGFR to set the basal profile. Results: Series of 88 cases of mammary carcinomas observed on operating parts, ranged in age between 28 and 84 years old, with an average of 51 ± 12, 8. Carcinoma infiltrating non-specific (DOCTORS) was the most frequent (87.5%). Ranks histo-prognostic Scarff Bloom and Richardson (SBR) 2 and 3 respectively accounted for 45.5 and 51.1% of cases and only 2, 3% of the DOCTORS were grade 1. The Luminal B (53.4%) was under the most common molecular group, followed by Luminal A (23.9%), HER2 + (15.9%) and triple negative (6.8%). The correlation of molecular type of tumors with different prognostic factors showed only one significant connection with the SBR grade.