ABSTRACT
Objective To restrospectively investigate clinical outcomes and prognositic factors in localized prostate cancer treated with neoadjuvant endocrine therapy followed by intensity modulated radiotherapy (IMRT). Methods Between March 2003 and October 2008, 54 localized prostate cancer treated by IMRT were recruited. All patients had received endocrine therapy before IMRT. The endocrine therapy included surgical castration or medical castration in combination with antiandrogens. The target of IMRT was the prostate and seminal vesicles with or without pelvis. The biochemical failure was defined according to the phoenix definition. By using the risk grouping standard proposed by D'Amico, patients were divided into three groups: low-risk group (n = 5), intermediate-risk group (n = 12), and high-risk group (n = 37). Kaplan-Meier method was used to calculate the overall survival rate. Prognostic factors were analyzed by univariate and multiple Cox regression analysis. Results The follow-up rate was 98%. The number of patients under follow-up was 39 at 3 years and 25 at 5 years. Potential prognostic factors, including risk groups, mode of endocrine therapy, time of endocrine therapy, phoenix grouping before IMRT, the prostate specific antigen doubling time (PSADT) before radiotherapy, PSA value before IMRT, interval of endocrine therapy and IMRT, irradiation region, and irradiation dose were analyzed by survival analysis. In univariate analysis, time of endocrine therapy (75 % vs 95 %, χ~2= 6. 45, P = 0. 011), phoenix grouping before IMRT (87% vs 96%, χ~2 = 4. 36, P = 0. 037), interval of endocrine therapy and IMRT (80% vs 95% ,χ~2= 11.60,P= 0. 001) ,irradiationdose(75% vs 91% ,χ~2=5.92,P= 0. 015) were statisticallysignificant prognostic factors for3 - year overall survival , and risk groups (85 vs 53 vs 29 , χ~2= 6. 40,P =0. 041) and PSADT before IMRT (62 vs 120, U =24. 50,P =0. 003) were significant factors for the median survival time. In the multiple Cox regression model, only time of endocrine therapy and phoenix grouping before IMRT were significantly related to the overall survival. The 3-year overall survival rates in patients with endocrine therapy less than 3 months versus more than 3 months were 75% versus 95% (χ~2= 5.45, P= 0.020). The 5-year overall survival rates in patients with biochemical failure versus nobiochemieal failure was 71% versus 92% (χ~2= 8.83 , P= 0.003) Conclusions Neoadjuvant endocrine therapy should last at least three months. Intensity modulate radiotherapy should start before biochemical failure after the endocrine therapy.