A study of Ki-67 labeling index in invasive nonmetastatic breast carcinoma.

Abstract

e14001 Background: This study evaluates the predictive value of Ki-67 in patients with invasive breast cancer receiving neoadjuvant chemotherapy (NACT) and its correlation with established prognostic factors. Methods: This is a prospective observational study of 165 invasive nonmetastatic breast cancer patients. Clinicopathological characteristics and Ki-67 labeling index were assessed. Patients with locally advanced breast carcinoma (LABC) received NACT and response rates were evaluated. Statistical significance was calculated using Chi Square test, unpaired t test, and non-parametric Mann-Whitney test. Results: Amongst the Ki-67 high group a significantly large majority of patients had grade 3 tumor (86.8% vs. 13.1%, p value < 0.001), ER negativity (56.8% vs. 11.4% p value < 0.001), PR negativity (65.3% vs. 18.6%, p value < 0.001), HER2/neu overexpression (47.4 % vs11.4 % , p value < 0.001) and lymphovascular invasion (LVI) (29.4% vs. 14.7% p value= 0.024). In high Ki-67 group 24.3% achieved CR compared...