[Clinicopathological evaluation of etoposide or estramustine phosphate in castrated patients with advanced prostatic cancer].

BACKGROUND

We conducted a multicentric randomized trial to compare bilateral orchiectomy versus bilateral orchiectomy plus etoposide or estramustine phosphate as first-line therapy for advanced prostatic cancer (stage D2).

METHODS

From January 1991 to December 1992 a total of 46 newly diagnosed cases (registered cases) of advanced (stage D2) prostatic cancer was randomized into 3 groups as follows; Group A: bilateral orchiectomy and 25 mg/day of etoposide every 2 weeks for 6 months. Group B: bilateral orchiectomy and 560 mg/day of estramustine phosphate for 6 months. Group C: bilateral orchiectomy alone. One of group A and one of group B were ineligible cases, so 44 were eligible. In the eligible cases, ages were ranged from 54 to 90 (mean of 71.2) years old. No significant difference of patients' characteristics was found among 3 groups and median follow-up period was 25 months. Response was evaluated based on the response criteria according to Japanese urological association. Specifically, a central pathologist who blinded to the treatment was employed for evaluating pathological response at six months.

RESULTS

Of the 44 eligible patients, 33 and 25 were evaluated for clinically and pathological analyses, respectively. Clinical response rates were 80% (12/15) of group A, 100% (4/4) of group B and 78.6% (11/14) of group C. No significant difference in the clinical response and survival rate was shown among the three groups. Significantly higher frequencies of side effects were noted in the grop B compared to the other two groups (p < 0.05) and cardiovascular complications were the most frequent in group B. Favorable pathological response was obtained in all of group B, but not statistically significant compared with 7/21 (33.3%) of response rate in group A and C. The pathological response was significantly correlated with the clinical one in all patients (p < 0.01). While 8 of 11 patients (73%) with pathological response grade 1, 2 and 3 achieved clinical PR (partial response) or CR (complete response), only 5 of 14 (36%) with grade 0 received PR or CR.

CONCLUSIONS

We conclude that low dose administration of etoposide or estramustine phosphate dose not improve clinical response and survival in a short term in castrated patients, but increases the adverse effects due to the drugs in these patients. In addition, the pathological evaluation at 6 months after treatment appears to reflect the clinical response at that time in newly diagnosed patients with advanced prostatic cancer.