Appendiceal Carcinoid Tumors: Is There a Survival Advantage to Colectomy over Appendectomy?

Background Guidelines recommend colectomy for appendiceal carcinoid tumors larger than 2 cm, but physicians debate whether colectomy would be beneficial in treating smaller tumors. We sought to determine when colectomy confers a survival advantage over appendectomy. Methods Appendiceal carcinoid patients in the US Surveillance, Epidemiology, and End Results (SEER) database (1988–2011) were stratified by age group, gender, TNM stage, tumor grade, and race. Kaplan-Meier and logistic regression analyses relating grade, stage, and receipt of colectomy to overall and cancer-specific survival were performed. Results Of 817 patients who underwent surgical extirpation of an appendiceal carcinoid, 338 (41%) had appendectomy alone and 479 (59%) had additional colectomy. Surprisingly, patients who underwent colectomy had worse cancer-specific survival (HR 1.98, 95% CI 1.32–2.98, p = 0.001) than those who underwent appendectomy, and colectomy did not confer a survival advantage over appendectomy in any subset analysis including low-grade or high-grade tumors, smaller or larger than 2 cm, or node-positive, non-metastatic tumors. Even when accounting for stage and grade, colectomy was not associated with significantly better survival rates. Furthermore, as colectomy frequency has increased over the last decade, the 5-year survival rate has trended down. The main predictors of cancer-specific mortality in carcinoid patients were high-grade (grades 3–4) and high-stage (node positive or metastatic) tumors. Conclusions Survival in patients with carcinoid tumor of the appendix is primarily determined by tumor grade and stage. Our study found no survival advantage to colectomy over appendectomy in a large cohort of patients with the disease. Further investigation is necessary prior to recommending change of practice for patients with appendiceal carcinoid tumors.