抄録
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 efficacy 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 findings 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 significantly 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 intermediate- and 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 findings suggest that the Ki-67 LI helps with the selection of adjuvant therapy in elderly patients.
