Prospective analysis of clinical outcomes and prognostic factors in patients with neuroendocrine tumors (NETs).

Abstract

4044 Background: The clinical course of NET patients (pts) remains poorly defined. We evaluated clinical outcomes and prognostic factors in 853 NET pts enrolled in a large, prospective outcomes study. Methods: NET pts presenting to our institution were enrolled in the study beginning in 2003. Demographics and clinical information were recorded from time of initial diagnosis since 1958 and updated at 6-month intervals following study enrollment. Prognostic factors were evaluated with multivariate Cox regression analysis including age, gender, presence (M1) or absence (M0) of distant metastasis at initial diagnoses, tumor subtype (pancreatic NET, small bowel carcinoid or other carcinoid), histologic grade (well, moderate, or poorly differentiated) and octreotide administration (yes/no). Results: 853 pts enrolled with a > 98% consent rate. Median follow-up (initial diagnosis to death or last known follow-up) was 4.45 years; 210 (24.6%) deaths occurred in this interval. Patients included 190 pancreatic NET, 321 small bowel carcinoid, and 342 other carcinoid; male: female = 46%: 54%; M0: M1 = 44%: 55.9%. Median OS for the entire cohort was 12.8 yrs. For M0 pts, median OS was not reached, 5-yr OS was 94%, and 5-yr DFS was 65%. Median time to recurrence for resected (M0) pts was 7.9 yrs (9 yrs for small bowel carcinoid, 4.6 yrs for pancreatic NET, and 10 yrs for other carcinoid). Older age, male gender, pancreatic primary site, and higher histologic grade were associated with higher risk of recurrence. For M1 patients, median OS was 7.6 yrs (12.5 yrs for small bowel carcinoid, 4.7 yrs for pancreatic NET, and 4.6 yrs for other carcinoid). Older age, male gender, pancreatic primary site, and higher histologic grade were associated with shorter survival in pts with metastatic disease. A possible association between octreotide treatment and improved survival in metastatic pts was observed, but did not reach statistical significance (HR for death = 0.87, p = 0.37). Conclusions: Pts with NETS experience prolonged survival, even in the setting of metastatic disease. Tumor recurrences, when they occur, may develop more than 5 years after initial diagnosis. No significant financial relationships to disclose.