KI-67 IMMUNOSTAINING IN 322 PRIMARY BREAST-CANCERS - ASSOCIATIONS WITH CLINICAL AND PATHOLOGICAL VARIABLES AND PROGNOSIS

Cell-proliferation markers are very important in the clinical manageme nt of cancer patients, and the identification of Ki-67 (a monoclonal a ntibody that recognizes proliferating cells) can make it easier to def ine the level of proliferative activity, This study investigated the a ssociations between the Ki-67 levels measured by means of immunohistoc hemistry, and other clinical and pathological variables and prognosis in 322 breast-cancer patients. A significant association was found (p < 0.001) between Ki-67 values and tumor size, nodal status, estrogen a nd progesterone receptor status; multivariate analysis showed that Ki- 67 levels were associated with disease-free and overall survival, thus confirming that it is an independent prognostic variable, Various sta tistical approaches were used in an attempt to establish the best cut- off point for dividing patients into groups at high or low risk of rel apse but, in this series, we could find no evidence leading to a singl e ''best'' cut off point. We conclude that the quantitative level of K i-67 could be used as a prognostic factor in breast-cancer patients. ( C) 1997 Wiley-Liss, Inc.