Background: Breast cancer is the most common cancer among Indian women. Majority of our patients do not have the traditional risk factors, and present in a locally advanced stage which progresses despite treatment. Studies have shown that it can be stratified in molecular subtypes by using a panel of immunohistochemical markers for estrogen, progesterone and HER 2neu receptor, which is closely related to its prognosis. Aim: This study was done to determine the prevalence of various molecular subtypes in our patients and its relation to various risk factors. Materials and Method: 446 breast cancer patients treated at Mahavir Cancer Sansthan, Patna from January 2015 toDecember 2015 were retrospectively analysed for their age, parity, history of breast feeding, menopausal status, height, weight, ER, PR & HER2neu receptor status. They were then classified in four molecular subgroups, Luminal A, Luminal B, Triple negative and HER2neu positive cancers and its relation to menopausal status and body mass index was analysed. Observations and Results: 68.38% patients were premenopausal with a mean age of 47.12 years. 24.38% patients were obese or overweight, with an average BMI of 22.38. Luminal A subtype followed by Triple Negative subtype was found in 37% and 29% of the patients respectively. The prevalence of Triple Negative subtype was more in premenopausal and overweight patients. Conclusion: Overall prevalence of triple negative subtype in our patient population is high esp. among premenopausal overweight patients.
