Men who elect to have a radical prostatectomy (surgical treatment for prostate cancer) as their primary treatment often panic if they find out that they had positive surgical margins (PSMs). Positive surgical margins are an indication for the use of adjuvant radiotherapy. Despite this automatic response the association between PSMs and prostate cancer-specific mortality (CSM) is poorly defined.
A recent study was conducted designed to analyze the association of PSMs with CSM, adjusting for fixed and time-dependent parameters. The researchers used theFine and Gray competing risk regression analysis was to model the clinical data and follow-up information of 11,521 men treated with surgery between 1987 and 2005. Two extended models were used that adjusted for the use of 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 prostate-specific antigen level at the start of treatment (? 0.5 vs >0.5 ng/ml).
The researchers used as their outcome measure prostate cancer-specific mortality.
They found that the 15-yr prostate cancer-specific mortality (CSM) rates for men with positive margins (PSMs) and negative surgical margins were 10% and 6%, respectively (p< 0.001). No significant association between PSM and CSM was observed in the conventional model with fixed covariates (hazard ratio [HR]: 1.04; 95% confidence interval [CI], 0.7-1.5; p=0.8) or in the two extended models that adjusted for postoperative radiotherapy (HR: 0.96; 95% CI, 0.7-1.4; p=0.9), or early and late postoperative radiotherapy (HR: 1.01; 95% CI, 0.7-1.4; p=0.9).
So, what does this mean?
Simply positive surgical margins (PSMs) alone are not associated with a significantly increased risk of CSM within 15 yr of surgery. Despite this the study authors did urge urologists to continue to strive to avoid PSMs, as they increase a man’s risk of biochemical recurrence and need for secondary therapy and may be a source of considerable patient anxiety.
Stephenson AJ, Eggener SE, Hernandez AV, Klein EA, Kattan MW, Wood DP Jr, Rabah DM, Eastham JA, Scardino PT.
Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.
Reference: Eur Urol. 2013 Aug 27. pii: S0302-2838(13)00864-6.
Joel T. Nowak, M.A., M.S.W.