WASHINGTON, DC USA (UroToday.com) - A positive surgical margin (PSM) alone does not negatively affect 15-year prostate cancer-specific mortality (PCSM) in this multi-institutional report.
A PSM is correlated with biochemical recurrence, but previous work by this group has not shown association with PCSM. They hypothesized that this lack of association may be due to the protective effect of postoperative radiotherapy on cancer progression. They used competing risk regression analysis to model the clinical data and follow-up information of 11,521 patients treated by radical prostatectomy for prostate cancer at 4 academic medical centers between 1987 and 2005. Two extended regression models were also used to analyze the association of PSM with PCSM that adjusted for postoperative radiotherapy, which was handled as a time-dependent covariate. Postoperative radiotherapy was modeled as a single parameter and also as early and late therapy, based on the PSA level at the start of treatment.
They found the 15-year PCSM for patients with PSM to be 10% and negative SM was 6%, (P <0.001). No significant association between PSM and PCSM was observed in the conventional model with fixed covariates or in the two extended models that adjusted for postoperative radiotherapy, or early and late postoperative radiotherapy.
Presented by Andrew J. Stephenson, et al. at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.