Background: Breast carcinoma has become a serious threat worldwide, owing to the increasing incidence of the disease in both developing and developed countries.

Aims and objectives: To study the association between Her2/neu and Ki-67 values and the extent of disease in breast carcinoma.

Methods: This was a hospital based cross-sectional study conducted over the duration of 18 months. All the females admitted with breast cancer reporting the health facility were included in the study. Their detailed medical history, clinical information, and laboratory investigations were recorded in excel and analysed.

Results: Mean age of participants was found to be 49.12±10.64 years. 91.2% females were multiparous. History of breast feeding was reported in 88.2% females, 38.2% females had history of HRT/OCP intake and 32.4% females had positive history of chemoradiation for breast cancer. On histopathology. Majority (85.3%) of cancer were ductal carcinoma. PR, ER, Her2neu and Ki67 >14 expression was reported in 41.2%, 55.9%, 8.8% and 94.1% of findings respectively. 96.2%, 91.2% and 85.3 of grade 3 tumours reported Ki67 >14, Her2neu and Her2neu/Ki67 expressions respectively.

Conclusion: This study explored the association of Her2/neu and Ki-67 positivity with the extent of disease in breast carcinoma. Understanding various factors is essential for tailored management strategies and highlights the need for early detection and comprehensive screening programs to improve patient prognosis. Therefore, it is recommended that all individuals diagnosed with breast cancer should undergo testing for four specific markers.