Approximately 3.8% of pancreatic masses are metastases from other primary malignancies. RCC is the most common with melanoma second. Of patients with metastatic RCC, 0.25-3% have pancreatic metastases.
Pancreatic metastases generally have a very indolent course and respond well to surgical excision as well as treatment with targeted therapy. Median time from nephrectomy to diagnosis of a pancreatic metastasis from RCC is 9 years. More than 50% are asymptomatic at diagnosis and only 30% of patients have more than one metastatic site within the pancreas (multifocal involvement). When it is the only site of metastases from RCC, surgical resection can be associated with 75% 5 year survival.In patients with pancreas only metastatic disease, it was recommended that an initial trial with targeted therapy would be reasonable to rule out further systemic progression prior to surgery. Multiple pancreatic metastases are more likely to be associated with other systemic metastatic disease. Pancreatic metastases can occur late in the natural history of RCC (20 or 30 years after initial treatment), and thus emphasize the need for long term followup of theses patients.(Source: European International Kidney Cancer Symposium : University of Barcelona : May 2007.)