Prevalence of Molecular Subtypes in Operated Cases of Breast Cancer and Its Clinicopathological Correlation: A Single Institute Study from a Tertiary Cancer Centre in North India.

Breast cancer has emerged as a major health problem among women in India. There are few Indian studies which have looked at prevalence of molecular subtypes of breast cancer in Indian population. The primary objective of our study was to find out the prevalence of various molecular subtypes in operated cases of breast cancer patients presenting to us. Three hundred sixty patients who were operated in our department were analysed. Clinicopathological features of all cases were recorded. Classification into various molecular subtypes was done using St. Gallen 2013 criteria. Luminal B HER2 negative was the predominant molecular subtype in our study population constituting 30.3% of patients. The percentage of aggressive subtypes, viz. triple negative breast cancer and HER2 enriched, were 21.7% and 11.4% respectively. Only 19.4% of patients in our study population had tumour size ≤ 2 cm with nodes being positive in 56.9% of our patients at presentation. Data from our study and other studies published from India show that the two most aggressive subtypes of, viz. triple negative breast cancer and HER2 enriched, may be more prevalent in our population as compared to western population.