FLOW CYTOMETRIC ANALYSIS OF APOPTOSIS AND BCL-2 IN PRIMARY BREAST CARCINOMAS - CLINICAL AND BIOLOGICAL IMPLICATIONS

Analysis of programmed cell death (apoptosis), of bcl-2, a critical re gulator of this process, and of the proliferative fraction may provide detailed information on the biologic characteristics of tumor cell po pulations, To investigate the potential role of these parameters in as sessing mammary carcinoma, we adapted flow cytometric procedures for c oncurrent measurement of apoptosis, bcl-2 expression, and cell prolife ration in 54 primary breast carcinomas and correlated the findings wit h traditional clinicopathologic information. Overall, a significant in verse relationship between apoptosis levels and bcl-2 expression was o bserved (P = 0.005). Apoptosis levels correlated significantly with DN A aneuploidy (P = 0.03) and S + G2M fractions (P = 0.005) of these tum ors, A significant correlation between bcl-2 expression and estrogen r eceptor positivity (P = 0.05) and DNA diploidy (P = 0.02) was noted. B cl-2 expression, however, was inversely correlated with S + G2M fracti ons (P = 0.001), We conclude that analysis of apoptosis and bcl-2 by f low cytometry allows further characterization of tumor cell population s that may be useful for prognostic and therapeutic management of brea st carcinoma. (C) 1996 Wiley-Liss, Inc.