Abstract: PD72-08
Sources of Funding: None

Introduction

To examine the patterns of distant recurrence in patients with biochemical failure after treatment with brachytherapy for prostate cancer.

Methods

We identified 4,036 patients treated with brachytherapy with or without external beam radiation (EBRT) and/or androgen deprivation therapy (ADT) for their diagnosis of prostate cancer. These patients were treated between 1992 to 2012 at a single institution. Of those patients, 266 had a PSA recurrence as defined by the Phoenix criteria. Of those patients, 92 were found to have distant failure as defined by metastases to bones, visceral organs, or lymph nodes. Kaplan Meier analysis was used to estimate 5-year freedom from distant failure. Univariable and multivariable cox regression analysis was performed to identify factors associated with distant failure.

Results

Median age on presentation for our cohort was 67.5 with a median Gleason score of 7 and PSA of 9.3 ng/ml. We identified a 5-year freedom from distant failure rate of 65.7% with a median follow up of 8.17 years and a median time to BCR of 2.9 years after initial treatment with brachytherapy. Of those patients with distant metastases, 73.9% of patients showed metastases to the bone alone, 16.3% showed metastases to lymph nodes alone, 3.2% showed metastases to visceral organs alone, and 6.5% exhibited multiple sites of metastatic spread simultaneously. On multivariate analysis, Gleason score was significantly associated with increased risk of distant failure (HR=1.30, P=.045).

Conclusions

Patients who experience distant metastatic disease after BCR following brachytherapy are most likely to exhibit metastatic disease to bones, although metastases to visceral organs and lymph nodes were also observed. Gleason score was significantly associated with increased risk of distant failure. Our study is the first to look at patterns of metastatic recurrence within a cohort of patients specifically treated with brachytherapy as the primary modality for prostate cancer therapy. The above findings can be used when counseling patients with prostate cancer who are seeking brachytherapy treatment as well as when considering which imaging modalities to obtain for detection of metastatic disease.

Funding

None