The expression and significance of Ki-67 in different subtype of breast cancer

Background and purpose:The established prognostic and predictive parameters of breast cancer were estrogen-receptor(ER),progesterone-receptor(PR) and human epidermal growth factor receptor-2(HER-2) status.The Ki-67 is now becoming a new research focus,and many researches showed that Ki-67 is an important biomarker after HER-2.This research aimed to study the expression and significance of Ki-67 in different subtypes of breast cancer.Methods:Clinical and pathological data of breast cancer patients,treated in Department of Breast Surgery,The First People’s Hospital of Changzhou from Jan.2010 to Dec.2010,were collected and analyzed.Immunohistochemical method was used to detect the expression of ER,PR,HER-2 and Ki-67 of these patients.Results:There were no correlations between the expression of Ki-67 and age or node metastasis of breast cancer patients,although there were significant differences in different tumor size of patients(P=0.001).The expressions of Ki-67 in stage Ⅰ,Ⅱ and Ⅲ patients were significantly higher than those in stage 0 patients,while there was no significant difference between the three mutually.The expressions of Ki-67 in ER negative patients were significantly higher than ER positive patients,and this trendency extended to PR negative and HER-2 positive patients(P0.05).The expressions of Ki-67 in Luminal B subtype,HER-2 over-expression subtype and basal like subtype were significantly higher than in Luminal A subtype(P0.001),but there was no significant difference between the three mutually.Conclusion:Ki-67 provides prognostic information combined with other biologic markers,and co-detection of Ki-67,ER,PR and HER-2 may be useful.