Hemicolectomy or appendectomy for appendiceal neuroendocrine tumours sized 1-2 cm? A retrospective population-based study of 1514 patients.

Abstract

Management of appendiceal neuroendocrine tumours (aNET) with a size of 1-2 cm is a topic of debate, with the conflict centred on the potential oncological benefits of right hemicolectomy (RHC) versus appendectomy and the impact of RHC on quality of life. A recent study suggested that RHC may not be needed for certain aNET 1-2 cm in size. A total of 1244 adult patients with aNET 1-2 cm (diagnosed 2012-2022) who underwent appendectomy or RHC were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Similarly, a total of 270 patients (diagnosed 2012-2021) were extracted from the National Cancer Registration and Analysis Service (NCRAS) database. Kaplan-Meier (KM) plots for overall survival (OS) were generated with log-rank tests (LR). Univariable and multivariable Cox regression for all-cause mortality were performed. In the NCRAS cohort, 159 and 111 patients underwent appendectomy and RHC, respectively. The median age was 41 and 51 years for appendectomy and RHC, respectively. Most patients were female (63.7%) and of white race (86.3%). Patients who underwent RHC had a higher proportion of node-positive disease. In the SEER cohort, 957 and 287 patients underwent appendectomy and RHC, respectively. Median age was 39 and 47 years for appendectomy and RHC, respectively. Most patients were females (65.3%) and of white race (67.7%). Patients who underwent RHC had a higher proportion of node-positive disease and M1 stage. Sex and race distribution were similar for the two procedures in both NCRAS and SEER. The KM plot for OS in NCRAS (p = .061) and SEER (p = .14) showed no statistical difference between appendectomy and RHC. Cox regression for all-cause mortality showed that there is no statistical difference between appendectomy and RHC in both cohorts after adjusting for other factors, including age and N stage. Cox regression for all-cause mortality for both cohorts combined showed the same result. Survival of appendectomy is non-inferior to RHC in the management of aNET 1-2 cm, even in patients with node-positive disease. These study findings address the gap in current clinical practice guidelines.