A proposed staging system for small bowel carcinoid tumors based on an analysis of 6,380 patients.

Background: Little is known about the long-term prognosis of small bowel carcinoids because currently no staging system exists.

Methods: A search of the Surveillance, Epidemiology and End Results (SEER) database identified 6,380 patients with small bowel carcinoid tumors from 1977 to 2004. Patients were analyzed according to various clinicopathologic factors and a tumor (T1, T2, T3), lymph node (N0, N1), and metastasis (M0, M1) staging system was created according to these parameters.

Results: Among the 6,380 patients, 2,985 women and 3,395 men, with a median age of 66 years (range 14-98), the median tumor size was 1.9 cm (range .1-30 cm). Multivariate analysis demonstrated that age, size of the primary tumor, and depth of invasion were significant factors. Four stages were created according to statistically significant prognostic factors: 13% of patients were classified into stage I, 31% into stage II, 16% into stage III, and 40% into stage IV. Five-year survival rates were 96%, 87%, 74%, and 43% for stages I through IV, respectively.

Conclusions: The newly developed TNM staging system accurately discriminates prognosis for small bowel carcinoid tumors.