Outcomes Of Patients With Pancreatic-Only Oligometastatic Renal Cell Carcinoma (Rcc)

681 Background: Patients (pts) with RCC and oligometastatic pancreas metastases are treated with pancreatectomy, stereotactic body radiation therapy (SBRT), or systemic therapy. The optimal approach is not clear. We aimed to evaluate the comparative efficacy of the modalities in terms of progression-free survival (PFS) and overall survival (OS). Methods: This IRB-approved, multi-institutional, retrospective study evaluated pts with pancreatic-only RCC metastasis without concurrent metastases elsewhere. Data on pt demographics, tumor characteristics, treatment, and outcomes were collected. PFS and OS in pts treated with pancreatectomy vs. systemic therapy were compared by log rank tests. Results: Fifty-one pts from 9 institutions were included. All had clear cell RCC; 50 pts had nephrectomy; 30 pts (58.8%) and 18 pts (35.3%) had IMDC favorable and intermediate risk, respectively. Median time from RCC diagnosis to oligometastatic disease was 120 months (mo) (range: 0, 175). As initial treatment, 23 (45%) pts had pancreatectomy (mostly partial); 25 (49%) had systemic therapy (VEGFR TKI and/or immunotherapy); 1 had SBRT; 2 had other treatments. Too few pts had SBRT for comparison. With a median follow-up of 25 mo (2, 68), median PFS for the population was 25 mo (17, 42 95% CI). Median PFS was 36 mo (8, 43 95% CI) for surgery pts and 22 mo (17, NR 95% CI) for systemic therapy pts; this was not statistically significant (NS), p = 0.3. Median OS for the population was 121 mo (100, NR 95% CI). With a median follow-up of 51 mo (2, 217), OS was 121 mo (100, NR 95% CI) for surgery pts and not reached (64, NR 95% CI) for systemic therapy pts; NS, p = 0.52. Conclusions: In this retrospective series, RCC pts with oligometastatic pancreatic-only disease had similar PFS and OS outcomes from initial pancreatectomy or systemic therapy. RCC pts with pancreas-only metastases represent a unique patient population and studies informing the underlying biology are needed to optimize clinical management.