Clinical significance of positive surgical margins confirmed
Posted Sep 28 2008 5:40pm
A publication by Pfitzenmaier et al. in BJU International has confirmed the clinical significance of positive surgical margins (PSMs) in patients ungergoing radical prostatectomy (RP) for localized prostate cancer, demonstrating that about 20 percent of patients with PSMs will go on to have local disease recurrence and about 15 percent will progress to metastatic disease.
Even though there is little debate that PSMs result in a higher risk of both local and distant recurrence of prostate cancer, the significance of a PSM after RP has only been tracked to biochemical progression in most studies. The research team set out to examine the effects of surgical margin status after radical prostatectomy, the location of the positive margins, and the number of positive surgical margins on biochemical and on longer-term clinical outcomes.
From their prospective database, 406 consecutive, well-described patients without neoadjuvant and/or any form of ”direct postoperative” adjuvant therapy who underwent RP were included. The median patient age was 64.7 years; the median preoperative PSA level was 7.9 ng/mL; and the median follow-up was 5.2 years. The group collected all available data on pathologic tumor stage, tumor grade, number and location of PSMs, PSA-free survival, local recurrence-free survival, metastasis-free survival, prostate cancer-specific, and overall survival prospectively.
The results of their analysis are as follows:
The overall rate of PSMs in these 406 patients was 17.2 percent. The percentage was higher in higher stage (P < 0.001) and higher grade tumors (P = 0.041).
For patients with a PSM, the PSA recurrence rate was 64.3 percent, the local recurrence rate was 18.6 percent, and the development of distant metastasis was 15.7 percent, and therefore much higher than in patients with negative margins (20.5, 2.7, and 1.5 respectively).
A PSM was an adverse predictor for PSA-free survival (P < 0.001), local recurrence-free survival (P = 0.002), and development of metastasis (P = 0.003).
The number and location of PSMs was of no additional prognostic value.
In numerical terms what this means is that about 70/406 patients had PSMs and that, of those 70 patients, 14 had local recurrence of their disease and 11 went on to have metastatic disease.
The authors conclude that a PSM increases the risk of biochemical and clinical disease progression after RP. The number and location of PSMs appears to be of relatively minor importance. Although only approximately 20 percent of patients with a PSM will develop local recurrence, surgeons should make every effort to reduce the rate of PSMs to improve cancer control.