Login to Access Video or Poster Abstract: MP70-09
Sources of Funding: Department of Urology, Winthrop University Hospital

Introduction

The Phoenix (PD) and Stuttgart definitions (SD) are used to define biochemical recurrence (BCR) in patients after radiotherapy and High Intensity Focused Ultrasound treatment of organ-confined prostate cancer (PCa) respectively. However, these definitions have also been applied to follow patients who have undergone cryosurgery. We sought to identify predictors of BCR using the PD and SD criteria and evaluate each criterion&[prime]s ability to predict biopsy-proven recurrence in primary focal cryosurgery (PFC) patients.

Methods

We performed a retrospective review of patients who underwent PFC at two tertiary care centers. Patients were followed with serial prostate specific antigen (PSA) tests. PSA levels, pre- and post-PFC biopsy Gleason scores, number of positive cores, and BCR (defined as: PD = [PSA nadir + 2 ng/mL] and SD = [PSA nadir + 1.2 ng/mL]) were recorded. Patients who experienced BCR were biopsied, monitored carefully or treated at the discretion of the treating urologist. Cox proportional regression and survival analyses were performed to assess time to BCR using the PD and SD criteria.

Results

Of 162 patients included [median (range) follow up: 36.6 (2.8-109.4) months] in the study, 64 (39.5%) and 98 (60.5%) experienced BCR based on PD and SD, respectively. On multivariate Cox regression analysis, the number of positive pre-PFC biopsy cores was an independent predictor of both PD (Hazard Ratio [HR]: 1.4, p=0.001) and SD (HR: 1.3, p=0.006) BCRs. Post-PFC PSA nadir was an independent predictor of BCR using the PD (HR: 2.2, p=0.024) but not SD (HR: 1.4, p=0.181) BCR. Survival analysis showed a 3-year BCR free survival of 55% and 36% for PD and SD respectively. Of those biopsied after BCR, 14/26 (53.8%) using the PD and 18/35 (51.4%) using the SD were found to have cancer (57.1% PD and 66.7% SD were clinically significant PCa).

Conclusions

Both the PD and the SD showed about a 50% biopsy-proven rate of recurrence after PFC. The number of positive cores on pretreatment biopsy appears to be a significant predictor of failure after PFC. The ideal definition of BCR after PFC remains to be elucidated.

Funding

Department of Urology, Winthrop University Hospital