Updated trends in second primary malignancy in patients with renal cell carcinoma: A retrospective population-based analysis.

e16546 Background: Survival outcomes for patients with renal cell carcinoma (RCC) have improved in recent years. However, the risk of developing second primary malignancy (SPM) in RCC survivors remains underexplored. SPM pose significant challenges in cancer survivors, impacting long-term morbidity and mortality. Therefore, we aim to evaluate and discuss incidence and risk of SPM in RCC patients using a large population-based dataset. Methods: We analyzed the Surveillance, Epidemiology, and End Results (SEER) database, comparing secondary cancer rates among RCC cases diagnosed from 2000 to 2021. The histologic code for RCC in the SEER database is 8312/3. A second primary malignancy was defined as a malignancy developing at least six months after the initial RCC diagnosis. We used the SEER Multiple Primary Standardized Incidence Ratios (MP-SIR) session to obtain the p-value, observed/expected (O/E) ratios, absolute excess risk (AER) per 10,000. Results: 43,477 Renal Cell Carcinoma cases from 2000-2021 met our inclusion criteria and were included in our study. Of these cases, 5,931 (13.6%) developed second primary malignancies. The mean age of SPM was 70.45 years. The risk of developing SPM was significantly higher than the general population, with an O/E ratio of 1.27 (CI 1.23-1.30, AER 42.67, p < 0.05). Most common SPM included Brain (O/E ratio 1.33 CI 1.02-1.72, p < 0.05), Pancreas (O/E ratio 1.18 CI 1.01-1.36, p < 0.05), Liver (O/E ratio 1.67 CI 1.4-1.97, p < 0.05), Lung (O/E ratio 1.27 CI 1.18-1.36, p < 0.05), Prostate (O/E ratio 1.16 CI 1.09-1.23, p < 0.05, Thyroid (O/E ratio 2.7 CI 2.29-3.17, p < 0.05), Multiple Myeloma (O/E ratio 1.42 CI 1.17-1.71, p < 0.05), AML (O/E ratio 1.6 CI 1.23-2.03, p < 0.05), CML (O/E ratio 1.77 CI 1.2-2.51, p < 0.05). Conclusions: Compared to the general population, there is a statistically significant increased risk of secondary primary malignancies in RCC patients. These findings highlight the importance of ongoing surveillance, risk stratification, and tailored follow-up strategies to improve early detection and intervention for SPM in RCC survivors.