Epidemiology, treatment and outcomes of gastroenteropancreatic neuroendocrine neoplasms

Abstract

To investigate incidence, treatment patterns and outcomes of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) in the United States. The 2019 National Cancer Database was searched for adult GEP-NEN patients. Main outcomes included overall and site-specific incidence, treatment patterns, and overall survival (OS). Overall survival was evaluated using averaged Cox regression. 86,324 GEP-NEN patients were included (6.33% of all GEP malignancies). From 2004 to 2016, annual GEP-NEN cases increased (n = 4,010 to n = 9,379), largely driven by low-stage, low-grade disease. Most patients received surgery, either alone (72.9%) or in combination with systemic therapy (4.9%). Longest overall survival (OS) was evident in patients with low stage and low grade GEP-NEN of the small intestine and rectum (p < 0.001). Patients undergoing surgical resection demonstrated longest OS. The addition of systemic therapy was most effective in high stage G3 NEN. Having higher income (≥$63,333) and private insurance or Medicare, but not Medicaid, was associated with improved survival. GEP-NEN incidence increases, likely due to improved detection and diagnosis. Treatment patterns have evolved to follow the latest international guidelines and site-specific improvement in survival is noted. In addition to disease specific factors, insurance access and socioeconomic factors emerged as potential targets for improving outcomes.

Keywords: Incidence; Neuroendocrine tumors; Survival.

Fig. 1

Annual case numbers for gastroenteropancreatic neuroendocrine neoplasms and gastroenteropancreatic non-endocrine neoplasms stratified by location. Overall mean increase provided as black line.

Fig. 2

Neuroendocrine neoplasm incidence according to primary location of the gastroenteropancreatic system.

Fig. 3

Kaplan-Meier plots showing shorter OS for Grade 3 disease across GI and pancreatic NEN. Grade 1 and Grade 2 tumors were not classified using current WHO criteria (mitotic count and Ki67 proliferative index) given NCBD limitations. Plots were limit to 132 months due to low subsequent event rates.

Fig. 4

Overall survival of GEP-NEN patients stratified by stage and treatment. Across all strata, patients undergoing surgical resection demonstrated favorable outcomes, with longest OS reported in patients with low-stage and low-grade GEP-NEN. Patients with GEP-NEN benefited from systemic therapy over best supportive care only in Grade 3 disease.