PURPOSE: A prospective phase II study was carried out to determine whether estramustine phosphate (EMP) plus vinblastine (VBL) in combination with radiotherapy (RT) would improve the control of locally advanced prostate cancer. The rationale for combining EMP plus VBL with RT was based on the clinical and radiobiological data that EMP plus VBL acted as an excellent radiation sensitizer in cultured human prostatic carcinoma cells with the property of tissue selectivity. The combined EMP and VBL were well tolerated in the phase II clinical study of patients with advanced prostate cancer. MATERIALS AND METHODS: Between January 1991 and July 1996, 65 patients, stage T2 (B2) through stage T4 (D1), were entered into the study. Gleason pattern scores ranged from 4 to 10. Pretreatment prostate-specific antigen (PSA) was as follows: < 20 in 21 patients (32%), 20 to 50 in 23 patients (35%), and > 50 in 21 patients (32%). The median age was 70 years (55-83). All patients were treated with megavoltage beam radiation with a total tumor dose of 65 to 70 Gy. Oral EMP 450 mg/m2 daily and VBL 3 mg/m2 weekly were given concomitantly in 46 patients during the 7- to 7 1/2-week course of radiotherapy. RESULTS: All patients showed prompt and complete tumor regression on digital rectal examination at 6 weeks following the completion of treatment. Median follow-up time is 43 months (3-65). PSA fell to an undetectable level by 6 weeks in 56 of 65 patients (86%). For the whole group at 5 years clinical control was 81%, but biochemical control (PSA < 4 ng/mL) was 48%. The likelihood of being free of biochemical relapse at 5 years was a function of initial PSA value (PSA < 20 in 64% of the cases, 21-50 in 60%, and > 50 in 0%). The biochemical-relapse-free survival at 5 years for each stage was T2, 49%; T3, 38%; and T4, 17%. In particular, a group of patients with pretreatment PSA levels of 20 to 50 ng/mL responded quite favorably to the present combined regimen in that only 40% of the patients showed a biochemical failure at 5 years, considering the high level of initial PSA. CONCLUSIONS: The present combined approach is effective in achieving a high rate of tumor control with no disproportionately enhanced side effects. The rapid regression of the tumor nodules and sustained freedom from biochemical relapse suggest excellent long-term tumor control, especially in the group of patients with pretreatment PSA levels of 20 to 50 ng/mL.
PURPOSE: A prospective phase II study was carried out to determine whether estramustine phosphate (EMP) plus vinblastine (VBL) in combination with radiotherapy (RT) would improve the control of locally advanced prostate cancer. The rationale for combining EMP plus VBL with RT was based on the clinical and radiobiological data that EMP plus VBL acted as an excellent radiation sensitizer in cultured humanprostatic carcinoma cells with the property of tissue selectivity. The combined EMP and VBL were well tolerated in the phase II clinical study of patients with advanced prostate cancer. MATERIALS AND METHODS: Between January 1991 and July 1996, 65 patients, stage T2 (B2) through stage T4 (D1), were entered into the study. Gleason pattern scores ranged from 4 to 10. Pretreatment prostate-specific antigen (PSA) was as follows: < 20 in 21 patients (32%), 20 to 50 in 23 patients (35%), and > 50 in 21 patients (32%). The median age was 70 years (55-83). All patients were treated with megavoltage beam radiation with a total tumor dose of 65 to 70 Gy. Oral EMP 450 mg/m2 daily and VBL 3 mg/m2 weekly were given concomitantly in 46 patients during the 7- to 7 1/2-week course of radiotherapy. RESULTS: All patients showed prompt and complete tumor regression on digital rectal examination at 6 weeks following the completion of treatment. Median follow-up time is 43 months (3-65). PSA fell to an undetectable level by 6 weeks in 56 of 65 patients (86%). For the whole group at 5 years clinical control was 81%, but biochemical control (PSA < 4 ng/mL) was 48%. The likelihood of being free of biochemical relapse at 5 years was a function of initial PSA value (PSA < 20 in 64% of the cases, 21-50 in 60%, and > 50 in 0%). The biochemical-relapse-free survival at 5 years for each stage was T2, 49%; T3, 38%; and T4, 17%. In particular, a group of patients with pretreatment PSA levels of 20 to 50 ng/mL responded quite favorably to the present combined regimen in that only 40% of the patients showed a biochemical failure at 5 years, considering the high level of initial PSA. CONCLUSIONS: The present combined approach is effective in achieving a high rate of tumor control with no disproportionately enhanced side effects. The rapid regression of the tumor nodules and sustained freedom from biochemical relapse suggest excellent long-term tumor control, especially in the group of patients with pretreatment PSA levels of 20 to 50 ng/mL.