Apoptosis in carcinoma of the bladder: relation with radiation treatment results.

PURPOSE: Radiotherapy is widely used in the treatment of bladder cancer. The search for biological parameters that could select patients who will respond to radiation treatment has become essential. The aim of this study is to assess whether the pretreatment apoptotic index is useful in predicting local control and survival in a group of bladder cancer patients treated by radiotherapy. METHODS AND MATERIALS: Fifty-five patients with invasive bladder carcinoma treated between 1983 and 1996 were included in this study. Radiotherapy was given to a median dose of 66 Gy, mean 63.28 Gy, in 1.8-2 Gy daily fractions. Apoptotic cells were studied in hematoxylin-eosin slides. Clinicopathological tumor characteristics were studied in relation to the apoptotic index, and as prognostic factors for local control and survival in both univariate and multivariate analysis.
RESULTS: Pretreatment apoptotic indexes were related to tumor stage, mitotic index, and Ki67 proliferation index. Five-year actuarial local control for the whole group was 45%. Patients with tumors showing low pretreatment apoptotic indexes had better local control (p < 0.037) and survival (p < 0.01) than highly apoptotic tumors. Tumor stage (T2 vs. T3-4) and the pretreatment apoptotic index were significant predictive factors for local control and survival in multivariate analysis.
CONCLUSIONS: The pretreatment apoptotic index is useful in predicting the clinical outcome of bladder cancer patients treated by radiotherapy. Assessment of biological tumor characteristics could allow the selection of patients for different treatment strategies.