Molecular subtypes and clinicopathological features of breast cancer in Mexican women

Breast cancer is a multifactorial and heterogeneous disease with distinct molecular features and histopathologic subtypes involving different therapeutic responses and clinical outcomes. Classification of breast cancer in molecular subtypes has made possible an approach to develop therapeutic strategies in order to have a better understanding of the breast cancer development. Due to the heterogeneity of the disease, there are still features to be elucidated in the behavior, etiology and clinical outcomes of each molecular subtype in breast cancer.

Variables measured in 1,695 cases of invasive breast carcinoma were age, histopathological diagnosis, histopathological grade, expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), cell proliferation marker (Ki67) and basal cytokeratins (CK 5/6). P values were obtained using Chi square test and hazard ratios were calculated with 95% confidence intervals.

An increase of aggressive molecular subtypes of breast cancer was observed. The mean age of incidence of breast cancer patients is decreasing, and breast cancer Patients younger than 40-years-old showed higher risk to exhibit Triple negative and Basal-like tumors.

The mean age for this pathology is decreasing in our population and there is predominance in the differential occurrence of etiologically distinct entities of breast cancer affecting to the young women.