Apoptosis during breast carcinoma progression

The purpose of this study was to investigate apoptosis, proliferation, and the expression of apoptosis-influencing proteins bcl-2 and bar and estrogen and progesterone receptors during breast carcinoma progression. The materi al consisted of 53 paired breast carcinoma samples representing primary and recurrent tumors and 24 control samples. The recurrent sample was located either in the breast scar tissue or at a distant metastatic site. Apoptosis was detected both morphologically and by 3' end labeling of fragmented DNA . Cell proliferation was evaluated immunohistochemically by the MIB index. The expressions of bcl-2, bar, and estrogen and progesterone receptors were studied immunohistochemically, There was a significant increase in the ext ent of apoptosis and proliferation in recurrent tumors compared to the prim ary lesions (P = 0.015 and P = 0.038, respectively). In primary tumors with an apoptotic index of >050%, the survival of the patients was significantl y shorter (P = 0.015), In cases with a significant increase in apoptosis or proliferation in the recurrent tumor, the survival of the patients was sig nificantly shorter (P = 0.009 and P = 0.003, respectively). Of the variable s analyzed, bcl-2 expression and a positive estrogen receptor status were s ignificantly associated with a low extent of apoptosis (P = 0.010 and P = 0 .042, respectively), Their changes were parallel to the changes in apoptosi s during tumor progression, although the associations did not reach statist ical significance, The results show that increased apoptosis is associated with a worse prognosis in breast carcinoma. A significant increase in apopt osis in recurrent breast carcinoma lesions predicts a worse clinical outcom e.