Association of partial nephrectomy with a long-term survival advantage in patients between age 20 and 44 with renal cell carcinomas ≤ 4 cm: An analysis of the SEER database.

408 Background: PN decreases the risk of developing chronic kidney disease as opposed to RN. While prior studies have demonstrated the survival advantage of PN in older patients, they have been criticized by selection bias in procedure selection due to comorbidities. We hypothesized that the long-standing effects of renal preservation would manifest in a survival advantage of a younger patient population, where this selection bias is minimized. Methods: The SEER 18-registries database was queried for patients between the ages of 20 to 44 that were surgically treated with either PN or RN for RCC between 1993 and 2003. We have excluded patients with metastatic or locally advanced disease and included patients with localized tumors ≤4 cm with known grade. The histologies selected were clear cell, papillary, chromophobe, sarcomatoid, collecting duct, and renal cell. The final cohort consisted of 222 and 494 subjects treated with PN and RN respectively. Chi-square analysis compared tumor variables and patient characteristics. Cancer-specific and overall survival rates were compared at 5 and 10 years using Kaplan-Meier analyses. Results: There were no differences between patients treated by PN or RN in demographics or tumor characteristics. Additionally, there was no difference in cancer-specific survival between the two groups at 5 or 10 years (p= 0.34 and p = 0.1 respectively). While there was no difference in 5-year overall survival (98.2% vs. 95.5%, p = 0.07), the patients treated with PN had an advantage in 10-year overall survival compared to patients treated with RN (94% vs. 89.7%, p = 0.025). Conclusions: Present SEER analyses demonstrate that when compared to RN, PN results in improved overall survival in patients treated for small, localized RCC. As expected, the survival advantage is observed late and supports the importance of long-term renal functional preservation. The present study of a younger patient population allows for minimizing selection bias in choosing surgical procedure due to comorbidities and provides further support for maximal renal preservation in patients with a life expectancy of 10 years or more.