Measures of cell turnover (proliferation and apoptosis) and their association with survival in breast cancer.

Our objective was to investigate the prognostic significance of cell turnover (apoptosis and proliferation) in breast cancer patients. Apoptosis was microscopically quantitated on histological sections from 791 breast cancer patients with long-term follow-up (median, 16.3 years). Apoptotic counts were also compared with proliferation data (mitotic counts and MIB-1 labeling); apoptosis data derived from terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay; and pathobiological variables, including p53, erbB-2, and estrogen receptor (ER). High apoptotic counts were associated with increased cellular proliferation, ER negativity, immunopositivity of erbB-2 and p53 (P < 0.0001), and shortened disease-specific survival (DSS; P = 0.0009) and disease-free survival (DFS; P = 0.0006). Other factors associated with shortened DFS and DSS by univariate analysis were high tumor grade, nodal metastases, and large tumor size (P < 0.0001 for each). Multivariate analysis of data for all of the patients demonstrated that tumor size, nodal status, ER, histological grade, and erbB-2 showed independent prognostic value. In node-negative patients, tumor size and mitotic rate per 1000 cells independently predicted DFS (P = 0.0055). Tumor grade was the only independent predictor of DSS. For node-positive patients, tumor size, nodal status, ER, and erbB-2 were independent prognostic factors. The number of mitoses per 1000 was independently associated with DFS (P = 0.043) but not with DSS. Apoptosis data did not provide independent prognostic value in any, node-positive or node-negative, breast cancer patients.