The value of external beam radiation in node positive prostate cancer

Abstract Purpose: The goal of this study was to evaluate the effect of local/regional treatment, particularly external beam radiation alone vs. radical prostatectomy plus radiation therapy in patients with pathologic node positive prostate cancer on survival. Methods : Medical records of all 116 patients who received their initial treatment at the Massachusetts General Hospital between 1980 and 1996 for adenocarcinoma of the prostate with pathologic confirmed nodal metastases and no distant metastases were reviewed. The mean follow up was 5.5 years. Overall survival, time to PSA failure on endocrine therapy, and time to first intervention were evaluated. The effect of the different treatment options were compared using multivariate Cox proportional hazard models to adjust for tumor characteristics that might influence survival. These included clinical T stage, clinical N stage, Gleason grade, number and location of positive lymph nodes and pretreatment PSA. Results: The combined patient population had a 5-year survival rate of 74% and a 10-year survival rate of 48%. Patients receiving local/regional treatment had adjusted 5 year survival rates of 80% compared to 27% for patients receiving no local/regional treatment (p = .001) with corresponding cumulative intervention rates (CIR) of 11% vs. 73% (p = .01) Patients receiving external beam radiation (XRT) alone did not differ significantly from those receiving prostatectomy plus radiation therapy in terms of survival (75 vs. 82%, p = .23) or cumulative intervention rates (14% vs. 14%, p = .94) Conclusion : Although it appears that all patients with node positive prostate cancer will eventually develop failure, this paper suggests local/regional therapy offers a medium term survival advantage over no local/regional treatment. The addition of prostatectomy did not confer a demonstrable advantage over radiation alone.