Positive surgical margins alone do not predict death from prostate cancer in men who undergo radical prostatectomy, investigators reported in the April issue of European Urology.
Positive surgical margins (PSMs) were not significantly associated with prostate cancer–specific mortality after adjustment for fixed covariates and postoperative radiotherapy, reported Dr. Andrew J. Stephenson, of the Cleveland Clinic’s Glickman Urological & Kidney Institute, and his associates.
Investigators analyzed data from 11,521 men with localized prostate cancer. Patients had undergone radical prostatectomy at four universities and cancer centers between 1987 and 2005.
At 15 years of follow-up, the prostate cancer–specific mortality for men with negative surgical margins was 6%, compared with 10% for men with PSMs (P less than .001).
But PSMs did not independently predict prostate cancer–specific mortality in regression models, the investigators reported (Eur. Urol. 2004;65:675-80).
That finding was true when researchers modeled only fixed covariates, such as age, Gleason score, seminal vesicle invasion, lymph node involvement, prostate-specific antigen (PSA), and extraprostatic extension (hazard ratio, 1.04; 95% confidence interval, 0.7-1.5), and also when they adjusted for postoperative radiotherapy, either as a single parameter (HR, 0.96; 95% CI, 0.7-1.4) or as early versus late treatment (HR, 1.01; 95% CI, 0.7-1.4).
The lack of an association called into question "the rationale for postoperative radiotherapy for PSMs in the absence of other adverse features," as well as "the relevance of PSM rates as a measure of surgical proficiency," the investigators said.
Even expert pathologists may not agree on PSMs and whether PSMs could be artifacts from surgery or pathologic processing, they noted. In addition, residual cancer from PSMs could lack biological characteristics needed for progression.
However, PSMs "should be avoided" because they worry patients and significantly increase the risks of biochemical recurrence and need for secondary treatment, Dr. Stephenson and associates said.
All patients in the study were treated at high-volume hospitals, and PSMs at low-volume hospitals could have a different prognosis. The study also lacked data on length and number of PSMs, the investigators noted.
Dr. Stephenson was partially supported by the Robert Wood Johnson Foundation Physician Faculty Scholars Program and the Astellas/American Urological Association Rising Stars in Urology Program. He reported no relevant financial conflicts of interest.