Association of Proliferative Activity in Invasive Ductal Carcinoma Breast in Pakistani Population

Background: Personalized medicine has played very important role in management of breast cancer. Proliferative index is one among the prognostic and predictive factor but unfortunately due to varied reports , no definite consensus and routine medical practice has been approved for it. The objective of the study is to observe the association of Ki-67 index using St. Gallen Conference criteria in invasive ductal carcinoma breast in Pakistani Population. Methods: Eighty-three patients with confirmed light microscopic diagnosis of primary invasive ductal carcinoma were recruited in this prospective study . Expression of Ki67 was determined by classifying as low (<15%) and high (>15%) Ki67 in tumour. Statistical analysis was performed to observe the association of Ki-67 with clinicopathological parameters and molecular group (i.e., Luminal A, Luminal B, Her2 enriched and triple negative). Results: Out of 83 patients, 73.5% of patients showed >15% Ki67 (p value <0.001). High expression of Ki 67 (>15%) was observed in 3.6%, 21.7% and 48.2 % of Nottingham grade I, II and III (p value=0.017) respectively. Among molecular group, high expression of Ki67 was observed 20.5% in Luminal A, 9.6% in Luminal B, 15.7% in Her2 enriched and 27.7% in triple negative groups (p= 0.017). There was no significant association observed in expression of Ki 67 among lymph node stage, tumour stage and Nottingham prognostic index. Conclusion: Higher Ki-67 reactivity is usually associated with higher-grade morphology of tumour. It can act as an independent predictor in assessment of tumour behavior. However, larger validation clinical studies are still required for confirmation of its importance and for routine practice.