[Hormonal therapy for prostate cancer: methods and prognosis].

Objective: To search for an effective hormonal therapy for delaying the progression of prostate cancer to androgen-independent prostate cancer (AIPC).
Methods: This study included 93 cases of prostate cancer confirmed by transrectal ultrasound-guided biopsy, 22 treated by bilateral orchiectomy plus bicalutamide as a continuous androgen deprivation (CAD) therapy, and the other 71 by the intermittent androgen deprivation (IAD) therapy, the latter divided into a standard IAD group (n = 29) and a modified IAD group (n = 42) to be treated by maximum androgen blockage (MAB) until the serum PSA level decreased to less than 0.2 microg/L and the medication was maintained for 3 months. Entering the intermittent period, the patients of the standard IAD group discontinued medication, while those in the modified IAD group withdrew luteinizing hormone-releasing hormone analogue (LHRH-a) but continued the use of bicalutamide. MAB was resumed in these two groups when serum PSA manifested a continuous rise and went up to 4 microg/L until prostate cancer progressed to AIPC. Comparisons were made among the CAD, standard IAD and modified IAD groups in the follow-up time, time of progression to CRPC and treatment cycles.
Results: The three groups of patients were well balanced in terms of demographics, baseline characteristics and follow-up time. The median times of progression to AIPC in the CAD, standard IAD and modified IAD groups were (26.50 +/- 4.15), (30.00 +/- 7.83) and (34.93 +/- 5.08) months, respectively, with statistically significant differences between the modified IAD group and the CAD (P = 0.001) and standard IAD (P = 0.032), but not between the latter two groups (P = 0.143). Kaplan-Meier survival curves showed a significantly longer median time of progression to AIPC in the modified than in the standard IAD group (P = 0.01). The mean cycle length was (16.13 +/- 3.33) months for the standard IAD group and (19.58 +/- 4.30) months for the modified IAD group, and the time off treatment of the first cycle was (9.6 +/- 3.2) months in the former and (14.2 +/- 3.7) months in the latter, with significant difference between the two groups (P = 0.001).
Conclusion: Compared with CAD and standard IAD, modified IAD therapy can significantly prolong the time of progression to AIPC in patients with prostate cancer.