Clinical outcome of patients with pancreatic metastases from renal cell cancer

BACKGROUND: Renal cell cancer (RCC) is one of the most frequent primary sites for metastatic pancreatic tumors although metastatic tumors are rare among pancreatic malignant tumors. The purpose of this study is to disclose the characterization and treatment outcomes of pancreatic metastases from RCC. METHODS: Of 262 patients with metastatic RCC treated at our hospital between 1999 and 2013, the data of 20 (7.6%) who simultaneously developed or subsequently acquired pancreatic metastases were retrospectively reviewed and statistically analyzed. RESULTS: The median follow-up period from RCC diagnosis and pancreatic metastases was 13.4 years (inter-quartile range: IQR, 7.8–15.5 years) and 3.8 years (IQR, 2.1–5.5 years), respectively. Median duration from diagnosis of RCC to pancreatic metastasis was 7.8 years (IQR, 4.2–12.7 years). During this observation period, the estimated median overall survival (OS) time from the diagnosis of RCC to death or from pancreatic metastasis to death was not reached. The probability of patients surviving after pancreatic metastasis at 1, 3, and 5 years was 100, 87.7, and 78.9%, respectively. The estimated OS period from the diagnosis of metastases to death of the patients with pancreatic metastasis was significantly longer than that of the patients with non-pancreatic metastasis (median OS 2.7 years) (P < 0.0001). Surgical management for pancreatic metastasis was performed in 15 patients (75%). When the median follow-up period for these surgeries was 3.5 years (IQR, 1.9–5.2 years), the estimated median recurrence-free survival was 1.8 years. For the patients with multiple metastatic sites, molecularly targeted therapies were given to six (30%) patients. When the median follow-up period was 4.1 years (IQR, 3.0–4.4 years), no disease progression was observed. CONCLUSIONS: The pancreas is frequently the only metastatic site and metastasis typically occurs a long time after nephrectomy. The OS period of these patients is long and both surgical and medical treatment resulted in good outcomes.