Positive Surgical Margins Predict Progression-free Survival After Nephron-sparing Surgery for Renal Cell Carcinoma: Results From a Single Center Cohort of 459 Cases With a Minimum Follow-up of 5 Years.

BACKGROUND

The role of positive surgical margins (PSMs) on the recurrence of renal cell carcinoma (RCC) after partial nephrectomy (PN) is debated, and available evidence lacks long-term data. The aim of this study was to evaluate the predictive role of PSMs on progression-free survival (PFS) in a large cohort followed for at least 5 years.

METHODS

This study was a retrospective analysis of a prospectively compiled single-institution database collecting complete information on more than 2700 patients who had undergone surgery for renal tumor. The data of all the patients submitted to PN for RCC and with least 5 years follow-up were extracted. Surgical specimens were examined at the time of surgery only by 2 expert uro-pathologists. A PSM was defined as the presence of cancer cells at the inked surface of the specimen. The role of PSMs on survival was estimated by Cox regression models adjusted for influent covariates.

RESULTS

A total of 459 patients fulfilled the inclusion criteria and were evaluated. PSMs were observed in 27 (5.9%) cases. No differences in preoperative and pathologic data were found comparing patients with and without PSMs. At a median follow-up of 96 months (interquartile range, 74-131 months), a clinically evident relapse of RCC was diagnosed in 36 (7.8%) patients at a median interval of 36 months from PN. Among these, 6 had a PSM for an incidence of relapse of 22.2% in the PSM group, whereas 30 had negative margins, for an incidence of 6.9% (P = .013). The sites of relapse were distant organs in 18 cases, and the kidney underwent PN in 21. The patients with PSMs showed a borderline significantly higher incidence of distant metastasis (11.1% vs. 3.5%; P = .071) and a significantly higher incidence of renal relapses (14.8% vs. 3.9%; P = .029). Multivariable Cox models confirmed that the presence of PSMs was an independent predictor of PFS (odds ratio, 3.127; P = .013).

CONCLUSIONS

PSMs are an independent predictor of PFS in patients who underwent PN for RCC, owing to a higher incidence of distant and local relapses. Surveillance in presence of PSMs should be intensified and extended for a long time.