Abstract: Background and purpose: Although intermittent endocrine therapy is a treatment strategy for new patients with advanced prostate cancer, the use of hormonal therapy is still controversial. This study aimed to investigate the efficacy of intermittent hormonal therapy for the patients with advanced prostate cancer and determine the factors influencing efficacy of the treatment. Methods: From Jul. 2009 to May 2015, patients with advanced prostate cancer were treated with 6 months of hormonal therapy, and then efficacy was assessed. A hundred and twenty-eight hormone sensitive patients were randomly divided into intermittent and continuous treatment groups, and were observed with efficacy, side effects, quality of life scores and other indicators. The prognostic factors for intermittent group were analyzed. Results: A total of 128 patients with advanced prostate cancer were enrolled in the study. Prostate-specific antigen (PSA) levels were significantly decreased in 96 patients after endocrine therapy. Among those, 43 patients received intermittent endocrine therapy while 53 patients received continuous endocrine therapy. The score of KPS in the intermittent treatment group was 82.6±7.4, which was significantly higher than that of the continuous group (KPS score was 69.8±8.7). There was a significant difference between them (P<0.05). The incidence of treatment related side effects and the proportion of developing hormone independent tumor in the intermittent group were significantly lower than that in the continuous treatment group (P<0.05). The 5-year survival rate in intermittent group was 72.1%, higher than that in the continuous group (63%). However, the difference was not statistically significant (P>0.5). PSA level in the early stage of endocrine therapy and G1eason score before treatment were important factors affecting the prognosis of patients. The patients in the intermittent group were followed up for 13-70 months, and received 1 to 4 cycles of treatment. The number of patients in the treatment was declined during the extension of the treatment, and the treatment interval was shorter. Conclusion: Intermittent endocrine therapy is an effective treatment for advanced prostate cancer. It is safe and reliable. It can improve the quality of life for patients and reduce the economic burden on them.

Key words: Prostate cancer, Hormonal therapy, Efficacy