PURPOSETo determine if familial prostate cancer patients have a less favorable prognosis than patients with sporadic prostate cancer after treatment for localized disease with either radiotherapy (RT) or radical prostatectomy (RP).PATIENTS AND METHODSOne thousand thirty-eight patients treated with either RT (n = 583) or RP (n = 455) were included in this analysis. These patients were noted as having a positive family history if they confirmed the diagnosis of prostate cancer in a first-degree relative. The outcome of interest was biochemical relapse-free survival (bRFS). We used proportional hazards to analyze the effect of the presence of family history and other potential confounding variables (ie, age, treatment modality, stage, biopsy Gleason sum [GS], and initial prostate-specific antigen [iPSA] levels) on treatment outcome.RESULTSEleven percent of all patients had a positive family history. The 5-year bRFS rates for patients with negative and positive family histories were 52% and 29%, respectively ...