Prevalence of breast cancer sub-types by immunohistochemistry in patients in the Regional General Hospital 72, Instituto Mexicano del Seguro Social

BackgroundBreast cancer mortality has increased in women 25 years and over, and since 2006 it has surpassed cervical cancer. Breast cancer is a heterogeneous disease, with several clinical and histological presentations that require a thorough study of all clinical and pathological parameters, including immunohistochemistry to classify it into subtypes, have a better prognosis, provide individualised treatment, increase survival, and reduce mortality.ObjectiveTo evaluate the prevalence of sub-types of breast cancer and the association with the clinical and histopathological features of the tumour.Material and methodsAn observational, retrospective, cross-sectional and analytical study was conducted on 1380 patients with a diagnosis of breast cancer, and they have been classified by immunohistochemistry into four subtypes: luminal A, triple negative, luminal B and HER2. An analysis was performed on the association with age, risk factors, and the clinical and histopathological features of the tumour.ResultsThe mean age of the patients was 53.3±11.4 years. The frequency was luminal A (65%), triple negative (14%), luminal B (12%), and HER2 (9%). The most frequent characteristics were in the 50–59 age range, late menopause, the right side, upper external quadrant, stage II, metastatic lymph nodes, and mastectomy.ConclusionThe most frequent sub-type was luminal A, and together with the luminal B they have better prognosis compared with the triple negative and HER2