APOPTOTIC INDEX CORRELATES TO BCL-2 AND P53 PROTEIN EXPRESSION, HISTOLOGICAL GRADE AND PROGNOSIS IN INVASIVE BREAST CANCERS

Apoptosis is considered to play a critical role in tumorigenesis. In o lder to clarify the significance of apoptosis in breast cancels, we qu antitated apoptotic cells by light microscopy in 126 patients with inv asive breast cancels, The expression of bc1-2, and p53, as regulators of apoptosis, was immunohistochemically analyzed Apoptotic index (AI) detected in the patients ranged from 0 to 48 per mm(2) of breast cance l cells (mean +/- SE, 11.0 +/- 0.97). Significantly higher AI was foun d for the tumors with grade 3 (p< 0.0001), high mitotic index (p < 0.0 001), and bc1-2 negativity (p = 0.004) compared with those with grade 1 or 2 low mitotic index, and bc1-2 expression, respectively. Moreover ; high AI was associated with larger tumor size (p= 0.008), positive l ymph nodes (p= 0.01), p53 positivity (p = 0.01), and advanced TNM stag e (p = 0.03). In survival analysis, we found that low AI, like bc1-2 a nd other conventional prognostic indicators, was significantly predict ive of better prognosis in terms of both disease-free survival (DFS) a nd overall survival (OS) (each, p < 0.0001). In multivariate analysis, AI failed to retain an independent significant value for DFS or OS. O ur results indicate that low AI is related to a number of clinicopatho logical and biologic parameters known to predict a lower risk of recur rence and is associated with a favourable survival in invasive breast cancer: However; it was nor an independent prognostic factor for clini cal outcome in this patient series.