Background: Regional lymphadenectomy is recommended for all colon carcinoids, whereas resection without lymphadenectomy is accepted for selected appendiceal and rectal carcinoids. We examined the relation of tumor size and depth to lymph node metastasis in order to determine whether colon carcinoids could be selected for endoscopic resection.
Methods: Patients were identified from the Surveillance Epidemiology and End Results Registry. The Pearson chi-square and the log rank tests were used. P < 0.05 was considered significant.
Results: We identified 929 patients who underwent resection of localized colon carcinoids without distant metastasis diagnosed from 1973 to 2006. The diagnosis of small and superficial tumors increased over time (p < 0.001). The presence of lymph node metastasis was adversely associated with survival (p < 0.001); however, there was only a trend toward independence on multivariate analysis (p = 0.054). Tumor size and depth were associated with lymph node metastasis (p < 0.001, p < 0.001). Tumors were subgrouped by size and depth to find cases with a low risk of lymph node metastasis. Intramucosal tumors < 1 cm had a 4% rate of lymph node metastasis, while all other subgroups had rates ≥ 14%.
Conclusion: Tumor size and depth predict lymph node metastasis for colon carcinoids. Endoscopic resection may be appropriate for intramucosal tumors <1 cm.