BERKELEY, CA (UroToday.com) - Tumor control during radical prostatectomy for localized prostate cancer can be compromised by positive surgical margins, i.e. by tumor cells located at the edge of the prostatectomy specimen. Our study shows, for the first time, that prognosis following prostatectomy is also affected by the presence of tumor cells that are merely close to the margin of resection, that is, a few layers of cells away from the ink (less than 0.1 mm). These close margins are currently reported as negative margins on a pathology report.
Three main questions arise from these findings:
How does a close surgical margin affect tumor recurrence?
For histological analysis, microscopic examination is performed on tissue sections at approximately 3-4 um interval. Thus, a close margin found on a histological slide can correspond to a positive margin located between the tissue sections examined. Viable cancer cells remaining in the patient have the potential to lead to clinical recurrence years after surgery.
Why doesn’t every close margin lead to a recurrence?
First, a close margin isn’t systematically associated with an under-sampled positive margin. Second, a positive surgical margin can correspond to non-viable tumor cells in the patient, such as cells that were cauterized or crushed during surgery.
What are the clinical implications of these findings?
In our study, the overall impact of close surgical margins on PSA recurrence-free survival was weak. This can easily be seen when comparing the hazard ratios of margin status, Gleason score, and tumor stage in multivariate models. Nevertheless, close surgical margins doubled the risk of recurrence across all prostate cancer risk groups. We therefore advocate a careful, long-term follow up even of patients that are otherwise at low risk of relapse. Finally, biochemical recurrence in a patient with a close margin conceptually indicates local recurrence, especially if there are no compelling arguments for a metastasis. This will have implications for salvage therapy.
Since the publication of this study, Izard et al.1 from the University of Washington have reported similar findings that corroborate our conclusions.
Reference:
- Izard PJ, True LD, May P, Ellis WJ, Lange PH, Lin DW, Wright JL: Prostate cancer ≤2 cells from the surgical margin predicts biochemical recurrence. Journal of Urology 2012 187:4 SUPPL. 1 (e663), Annual congress of the AUA, 2012
Written by:
Chin-Lee Wu, MD, PhD* as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
*Associate Professor of Pathology
Harvard Medical School
Associate Pathologist
Director, Urology Research Lab
Massachusetts General Hospital
55 Fruit Street, Warren 105
Boston, MA 02114 USA
Email
A close surgical margin after radical prostatectomy is an independent predictor of recurrence - Abstract
More Information about Beyond the Abstract