Effect of treatment center volume on outcomes in gastroenteropancreatic neuroendocrine tumor patients.

BACKGROUND: Medical centers with varying levels of expertise treat gastroenteropancreatic neuroendocrine tumors (GEP-NETs), which are relatively rare tumors. This study assesses the impact of center volume on GEP-NET treatment outcomes. METHODS: We used the Surveillance, Epidemiology, and End Results (SEER) registry linked to Medicare claims data. The data includes patients diagnosed between 1995 and 2010 who had no health maintenance organization (HMO) coverage, participated in Medicare parts A and B, were older than 65 at diagnosis, had tumor differentiation information, and had no secondary cancer. We identified medical centers at which patients received GEP-NET treatment (surgery, chemotherapy, somatostatin analogues, or radiation therapy) using Medicare claims data. Center volume was divided into 3 tiers - low, medium, and high - based on the number of unique GEP-NET patients treated by a medical center over 2 years. We used Kaplan-Meier curves and Cox regression to assess the association between volume and disease-specific survival. RESULTS: We identified 899 GEP-NET patients, of whom 37, 45, and 18% received treatment at low, medium volume, and high-volume centers, respectively. Median disease-specific survival for patients at low and medium tiers were 1.4 years and 5.3 years, respectively, but was not reached for patients at high volume centers. Results showed that patients treated at high volume centers had better survival than those treated in low volume centers (HR: 0.63, 95% CI: 0.4-0.9), but showed no difference in outcomes between medium and high-volume centers. CONCLUSIONS: Our results suggest that for these increasingly common tumors, referral to a tertiary care center may be indicated. Physicians caring for GEP-NET patients should consider early referral to high volume centers.

Impact of Mesenteric Mass in Patients With Midgut Neuroendocrine Tumors.

OBJECTIVES: In this study, we used the institutional pathological and clinical databases from The Mount Sinai Hospital to investigate the impact of mesenteric mass on clinical and staging features in small intestinal neuroendocrine tumors. METHODS: Demographic, clinical, and staging data were collected. Tumor-node-metastasis stage was assigned according to the American Joint Committee on Cancer eighth edition staging manual. We used a χ-square test to evaluate the association between mesenteric mass and presenting symptoms, as well as the association between mesenteric mass and tumor characteristics, type of surgical resection, and use of somatostatin analogues. RESULTS: Presence of mesenteric mass was strongly associated with highly symptomatic clinical presentation (P < 0.0001). Patients with a mesenteric mass were more likely to have more advanced tumor status (T3 and T4; P = 0.005). The presence of a mesenteric mass was also more strongly associated with metastatic disease (P = 0.002). Patients with a mesenteric mass were more likely to undergo extensive surgical resection (P < 0.0001) and be treated with somatostatin analogues (P < 0.003). CONCLUSIONS: The data confirm our clinical observations that mesenteric involvement represents more extensive disease and is also associated with more aggressive treatment.