Non-functional Neuroendocrine Carcinoma of the Pancreas: Incidence, Tumor Biology, and Outcomes in 2,158 Patients

Pancreatic neuroendocrine cancer is a rare, indolent malignancy with no effective systemic therapy currently available. This population-based analysis evaluated the hypothesis that long-term survival benefit is greater with aggressive, rather than limited, surgical therapy. Non-functional pancreatic neuroendocrine carcinoma (NF-pNEC) cases diagnosed from 1973 to 2004 were retrieved from the SEER database. A total of 2,158 patients with NF-pNEC were identified, representing 2% of all pancreatic malignancies. The annual incidence increased from 1.4 to 3.0 per million during the study period. On average, tumors measured 59 +/- 35 mm (median 50), and age at diagnosis was 59 +/- 15 years; 29% of patients were younger than 50. Nodal (44%) and systemic metastases (60%) were common. Overall the 5-, 10-, and 20-year survival rates were 33%, 17%, and 10%, respectively. Removal of the primary tumor significantly prolonged survival in the entire cohort (median 1.2 vs. 8.4 years; p < 0.001) and among those with metastases (median 1.0 vs. 4.8 years; p < 0.001). No survival difference was seen between enucleation and resection of the primary tumor (median 10.2 versus 9.2 years, p = 0.456). This study suggests that surgical therapy improves survival among patients with localized, as well as metastatic, NF-pNEC. Enucleation may be oncologically equivalent to resection.