Immunohistochemistry Based Molecular Subtyping of Breast Carcinoma in Industrial Population in India, Haryana: A Correlation with Clinicopathological Parameters

Background: Breast carcinoma is the most prevalent malignancy in females globally and also the leading cause of cancer-related mortality. The immunohistochemistry (IHC)-based molecular subtyping has put newer insights into the biological behaviour and clinical management of breast carcinoma. We conducted the present study to correlate the four IHC-based molecular subtypes: Luminal A, Luminal B, Human epidermal growth factor receptor 2 positive, and triple negative breast carcinoma with various clinicopathological parameters amongst the industrial population of Haryana. Method: This cross-sectional study was conducted on 92 cases of invasive breast carcinoma, who underwent modified radical mastectomy over a period of 2.5 years with the prior approval of Institutional Ethical Committee at ESIC Medical College and Hospital, Faridabad. We performed routine histopathological examination along with IHC (Estrogen receptor, Progesterone receptor and Human epidermal growth factor receptor 2) study. The correlation of the four molecular subtypes with various clinicopathological parameters were also studied. We analysed the data using SPSS software. Results: The mean age of the patients in this study was 47 years with a maximum number of cases in the 3rd and 4th decade of their life. The most common subtype was luminal B (40.9%) with the maximum number of cases presenting in stage II (53.26%) and with grade II (51.1%). Triple-negative breast cancer was found to be associated with brisk mitosis, lymphovascular invasion (66.67%), necrosis (77.78%), and ductal carcinoma in situ (66.67%). These findings were clinically significant. (p <0.05) Conclusion: The early age of presentation of breast carcinoma in the industrial population would warrant the need to focus on various molecular subtypes and clinicopathological parameters that may have different prognostic implications in this population.