Evaluation of the Prognostic Value of Ki-67 in Early Stage Breast Cancer

Abstract

Background: Breast cancer is a disease which have a variety of important features whose different phenotype only partially summarize the underlying biological complexity. Treatment choices in routine management principally rely on the clinical and pathological characteristics of the disease, although molecular classification currently offers information alongside that provided by clinical and pathological examination. The decision to offer adjuvant chemotherapy to patients is not easy and the knowledge of prognostic factors is mandatory. Ki 67 plays an important role in this context, especially in patients who do not have access to genetic signatures. Aim of the work: This study aims to evaluate the value of Ki67 as a prognostic factor in relation to disease free survival and other clinico-pathological factors in Egyptian females with early stage breast cancer. Patients and Methods: Type of study: This is a retrospective cohort study. Study population: It consisted of 124 patients diagnosed with early stage breast cancer. Study Period: They were diagnosed between January 2011 and December 2015. Study setting: The patients were following up in Ain Shams University Hospital clinical oncology department. Information were manually retrieved from the records of the clinical oncology department at Ain Shams university hospitals. Clinical and pathological tumor characteristics were collected using patient charts and pathology reports. Results: Our study showed a significant relation between Ki67 index and estrogen receptors, progesterone receptors and Her2 neu status. Ki67 was found to be statistically significantly correlated to intrinsic subtypes. Our study was unable to find out the effect of Ki67 on disease free survival. Cox regression analysis revealed a statistical significant influence of estrogen receptors status on disease free survival. It also revealed statistical prognostic effect of progesterone receptors and Her2 status on disease free survival. Covariate analysis of results in our study showed that tumor with T4 stage has a significant prognostic effect on disease free survival. Conclusion: ki67 index may have a prognostic role in management of early stage breast cancer in relation to other prognostic markers like hormone receptor status and HER2neu expression. Moreover, immunohisto-chemistry-based subtyping is extremely important to classify breast carcinoma into molecular subtypes that vary in clinic-pathological features and would lead to different prognosis. Thus, molecular subtyping is essential for breast carcinoma management.