Abstract: PD20-08
Sources of Funding: None

Introduction

Partial nephrectomy (PN) has become the standard treatment for small renal masses. However; it carries a risk of incomplete tumor excision and potential tumor recurrence. As such, positive surgical margins (PSMs) remain a concerning issue. We evaluated outcomes of PSMs and risk of disease recurrence in patients with clinically localized renal neoplasms undergoing PN.

Methods

We reviewed our database to identify patients who underwent PN between 1990 and 2015 with PSMs on final pathology. Tumors with malignant pathology were isolated and statistically analyzed for demographics and oncologic follow-up. Cancer-specific survival, overall survival and recurrence-free survival were estimated using the Kaplan-Meier method.

Results

A total of 2297 patients underwent PN at our institution. Of these, 50 (2.2%) patients had PSMs on final pathology. There were 30 (1.3%) patients with renal cell carcinoma (RCC) and 20 (0.9%) patients with benign tumors who had PSMs. Patient demographics for those who had PSMs with malignant pathology reported as median for age of 59 years, BMI of 31 kg/m2 and Charlson Comorbidity Index of 2. The primary tumor size was 3.2 cm (range, 2.0-10.0), nephrometry score was 8.0 (range, 5-10), and median number of resected tumors was 1.0 (range, 1-10). There were 17 (57%) patients with bilateral renal masses at presentation, of these 11 (64%) patients have had prior surgical treatment for RCC including 2 of 3 patients with hereditary RCC. Histology was most commonly clear-cell RCC in 20 (67%), stage was primarily pT1a in 21 (70%), and Fuhrman was grade 2 in 17 (57%) of these tumors. _x000D_ There were 7 (23%), and 5 (17%) patients with PSMs that developed recurrence and metastasis; respectively during a median follow-up of 57 months. Recurrence at the surgical bed was found in 3 patients whereas contralateral and bilateral kidney recurrences were found in 2 patients each. Metastases to bone and lung were found 1 and 4 patients; respectively. As projected by the Kaplan-Meier method in the population with RCC, the 5-year cancer-specific survival, overall survival and recurrence-free survival was 95.8%, 92% and 78.2%; respectively. _x000D_

Conclusions

There was a low rate of PSMs in our large cohort of patients undergoing PN despite complexity of these renal masses and disease multifocality at presentation. However; efforts should be made intraoperatively to achieve complete surgical excision with negative margins since patients with PSMs have an increased risk for disease recurrence.

Funding

None