Expression of Ki-67 in Patients of Invasive Ductal Carcinoma and its Correlation with Histological Grades
Abstract
Background: Histological grade which is an important determinant of breast cancer prognosis. It is evaluated by pathologists according to the Nottingham modification of the Scarff-Bloom-Richardson (SBR) grading system. It could be incorporated into algorithms to choose the most appropriate treatment for patients with breast cancer. Prognostic factors are important in breast cancer as they allow the identification of high-risk patients, for which, adjuvant therapy can improve the prognosis. Amongst the prognostic markers, the Ki67 index is considered a practical method for predicting the responsiveness to chemotherapy. Objective: To compare histological grades of carcinoma with Ki67 expression in patients of invasive ductal carcinoma breast. Study Design: Descriptive, cross-sectional. Settings: Department of Pathology, PNS SHIFA Hospital, Karachi. Duration: 13th February 2021 to 12th August 2021. Methods: 77 cases of invasive ductal carcinoma of both genders and ages ranging from 25-85 years were included. Histologic grading was performed on H&E stained sections using the Nottingham modification of the Scarff-Bloom-Richardson (SBR) grading system. Immunohistochemistry for Ki67 was done on FFPE tissues using the DAKO Envision kit. Ki67 the index was determined as the number of Ki67 positive cells per 500 tumor cells. Ki67 was graded as low <14% and high ≥14%. Results: In our study, histological grading of invasive ductal carcinoma was found to be as follows; grade I in 01 (1.30%), grade II in 53 (68.83%), and grade III in 23 (29.87%) patients. A high Ki67 index was found in 70 (90.91%) patients. All grade III tumors showed high expression of Ki67, while 88.68% of grade II tumors showed high expression. None of the grade I tumors showed high Ki67 expression. Conclusion: This study showed that grade II (75.71%) was the most common grade of invasive ductal carcinoma followed by grade III (22.86%). High expression of Ki67 correlates with a higher histological grade.