Outcomes for patients with extraprostatic prostate cancer treated with trimodality therapy, including brachytherapy,...

To evaluate the efficacy of multimodality therapy consisting of hormone therapy (HT), brachytherapy (BT), and external beam radiotherapy (EBRT) in extraprostatic prostate cancer and identify factors with predictive value.

Between June 1992 and October 2006, 97 patients with extraprostatic prostate cancer received permanent seed implant BT. Extraprostatic disease was defined by one or more of the following: positive seminal vesicle biopsy (n=56), positive lymph node dissection (n=8), or a clinical tumor stage of T3 (n=48). Treatment consisted of BT alone with (103)Pd or (125)I (n=4); HT and BT (n=3); BT and EBRT (n=2); or trimodality therapy with HT, BT, and EBRT (n=88). Median followup was 69 (range, 23-182) months. Freedom from biochemical failure (FBF) rates were calculated using the Phoenix criteria.

The 7-year actuarial FBF, freedom from distant metastases, disease-specific survival, and overall survival rates were 67%, 82%, 96%, and 81%, respectively. Biologically effective dose (BED) was the only variable significantly impacting FBF rates. FBF at 7 years was 60% vs. 74% for BED below 200 and 200 or above, respectively (p=0.048). Trends toward worse outcomes were noted with increasing Gleason score, with 7-year FBF rates of 86% vs. 71% vs. 55% for scores of 6 or less, 7, and 8-10, respectively (p=0.090). BED was the only significant predictor of FBF in multivariate analysis (p=0.032). None of the predictors were significant in multivariable analyses for the other outcomes studied.

Trimodality approach achieves durable biochemical control in most patients with historically poor prognosis T3 prostate cancer. BED above 200Gy was associated with superior FBF.