Positive surgical margins can predict prostate cancer mortality
MedWire News: US study results show that the presence of positive surgical margins (PSMs) after radical prostatectomy is an independent predictor for prostate cancer-specific mortality (PCSM).
Furthermore, in men at greatest risk for PCSM, the presence of PSMs indicated a shorter 7-year disease-specific survival compared with having negative surgical margins (NSMs).
“These data demonstrate the importance of optimizing surgical technique to achieve a NSM in prostate cancer, and underscore the need for pathological standardizations of tissue processing to accurately define surgical margin status,” say Jonathan Wright (University of Washington School of Medicine, Seattle) and colleagues.
The team evaluated the association between margin status and risk for PCSM in a cohort of 65,633 radical prostatectomy patients.
In all, 13,905 men had PSMs, and PSMs were more common in men with stage T3 disease, at 43.8% versus 17.7% in those with T2 disease, and those with higher grade (Gleason score 8–10), at 27.5% versus 18.3% in patients with lower grade cancer (Gleason score 2–7).
Overall, 291 men died of prostate cancer during the median 50-month follow-up, and the cumulative PCSM rate was significantly higher among men with PSMs than in those with NSMs, at 0.86% versus 0.33%, respectively.
After stratifying participants by stage and grade, men with high grade (T3) tumors – and thus at greatest risk for PCSM – had better 7-year disease-free survival rates if they had NSMs than if they had PSMs, at 97.6% versus 92.4%.
Unadjusted analysis revealed a 2.55-fold increased risk for PCSM among men with PSMs compared with those who had NSMs, and this association was confirmed in multivariate analysis.
After adjusting for stage, grade, additional radiotherapy and other potential confounders, PSMs remained independently associated with PCSM, conferring a 70% increased risk compared with NSMs.
Writing in the Journal of Urology, Wright et al explain that existing data have shown an association between PSMs and biochemical recurrence (BCR) in radical prostatectomy patients.
However, they believe PCSM to be “a more informative endpoint,” as “many patients experiencing BCR will not die of prostate cancer and consequently BCR is not a universally accepted surrogate for PCSM.”
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By Sarah Guy