Abstract: PD20-09
Sources of Funding: None

Introduction

Utilization of partial nephrectomy (PNx) has expanded to include treatment of an increasing number of renal masses ≥4cm by various surgical approaches. Recent evidence has suggested risk of recurrence with positive surgical margin (PSM) is increased in the presence of high-risk features, including stage ≥T2. While surgical approach has been associated with PSM in PNx for small renal masses (<4 cm), its impact on margin status for large renal masses is unclear.

Methods

Using the National Cancer Data Base (NCDB), we identified patients undergoing PNx for clinical T1b and T2a renal cell carcinoma (RCC) from 2011 to 2013. Primary outcome was surgical margin status. Multivariable regression modeling was performed to identify patient, facility, and surgical factors, including surgical approach (open, laparoscopic, or robotic) on PSM in patients undergoing PNx.

Results

Of 7495 undergoing PNx for cT1b and T2a renal masses from 2011 to 2013, 504 (6.72%) had PSM. On multivariable analysis, age > 60 years (OR 1.57 [95% CI 1.01-2.44] p=0.048), African American race (OR 1.52 [95% CI 1.06-2.17] p=0.023), education level (OR 1.48 [95% CI 1.03-2.14] p=0.034), rural setting (OR 4.82 [95% CI 2.45-9.46] p<0.01), mixed histology (OR 1.84 [95% CI 1.04-3.24] p=0.035), undifferentiated tumor grade (OR 2.42 [95% CI 1.26-4.65] p<0.01), as well as having surgery performed at a non-academic facility (OR 1.57 [95% CI 1.15-2.15] p<0.01) were associated with PSM. Surgical approach (laparoscopic and robotic vs. open) (p=0.119 and p=0.437, respectively) and stage (T2a vs. T1b) (p=0.182) were not associated with PSM.

Conclusions

Surgical approach is not independently associated with increased risk of PSM for large renal masses, which is contrary to previous reports pertaining to cT1a lesions. Surgery at an academic facility was protective against having a positive margin. These data are important given the unclear oncologic significance of margin status in these tumors.

Funding

None