Significance of Ki-67 Expression and Risk Category (St. Gallen 2007) in Elderly Breast Cancer Patients, with Emphasis on the Need for Postoperative Adjuvant Therapy

Abstract

: Breast cancer is increasing in the elderly. Although elderly breast cancer patients frequently receive less invasive therapy, its appropriateness is debatable. Ki-67 expression is a controversial prognostic factor and predictor of the ef cacy of postoperative adjuvant therapy. This study investigated the value of the Ki-67 labeling index LI in elderly breast cancer patients, especially with respect to adjuvant therapy. This retrospective study investigated 82 primary breast cancer patients aged ≥ 70 years who underwent surgery between 1995 and 2005. Their clinicopathological ndings were reviewed and their Ki-67 LIs were determined. The patients mean age was 78 years, the mean observation period was 53.8 months, and 60 patients 73.2% underwent adjuvant therapy. The St. Gallen 2007 risk category and the Ki-67 LI mean, 15.3% were both signi cantly correlated with relapse and prognosis. In the 31 cases with a low Ki-67 LI 10% , 1 patient who underwent adjuvant treatment relapsed, but there were no deaths. Among the intermediateand high-risk patients, Ki-67 was low in 15 ; 1 patient who underwent adjuvant treatment relapsed, but there were no deaths. For elderly breast cancer patients aged ≥ 70 years categorized low risk by St. Gallen 2007 or with a low Ki-67 LI, the risk of relapse and death appears to be low regardless of adjuvant therapy. Though further investigation is needed to determine a method of measuring the Ki-67 LI and determining a cut-off value, our ndings suggest that the Ki-67 LI helps with the selection of adjuvant therapy in elderly patients.