Histomolecular Trends of Breast Carcinoma: Insights from Tertiary Care Centre of Northern India

Introduction: The most prevalent cancer among women worldwide is breast cancer. This can be separated into three molecular subtypes: Luminal, HER2-enriched, and triple negative. There is significant regional variation in epidemiology profile of this malignancy in India. The present study provides insightful information about breast cancer cases from North India. Aim: To study the distribution and patterns of histomorphology and molecular subtypes of carcinoma breast over a period of one year. Materials and Methods: The present prospective cross sectional study conducted in a Tertiary Centre in Ludhiana, Punjab, India, over a period of 12 months (September 2022 to September 2023). All cases of Invasive Breast Carcinoma (IBC) undergoing Immunohistochemistry (IHC) testing were included in the study. A total of 15,395 biopsy and surgical specimens were received during this period, out of which 203 cases were of IBC on which IHC testing was done. Molecular subtypes were determined using expression of oestrogen and progesterone receptors, HER2/neu and Ki-67. Additional markers including CK, GATA-3, mammaglobin, CK5/6, SOX-10, p40, Vimentin, etc., were put, wherever required. Trends of molecular subtypes and histomorphology were studied. The histopathology parameters included Modified Bloom Richardson (MBR) grade, Ductal Carcinoma In Situ (DCIS) (pattern and grade), tumour necrosis, skin invasion, lymphovascular and perineural invasion, tumour margins, lymph node status, Extranodal Extension (ENE) (if any), etc. All collected data was entered into Microsoft Excel spreadsheet and anaysed using software Statistical Package for Social Sciences (SPSS) 26. Normality of continuous variables was assessed using Shapiro-Wilk test, and data was presented as mean ± Standard Deviation (SD). Fisher-exact test was utilised if any of the frequencies were