Predictors of Recurrence in Nonmetastatic Appendiceal Epithelial Cancers: An Updated Single-Center Experience Over 25 Years.

Background: Appendiceal epithelial tumors are rare and encompass a broad set of adenocarcinoma histologies, including mucinous (mAC), colonic-type (cAC), and goblet cell (GCA) adenocarcinomas. It has previously been reported that nodal disease predicted recurrence in patients with nonmetastatic appendiceal adenocarcinomas, supporting diagnostic laparoscopy with right hemicolectomy for staging and assessment for risk of recurrence. In this update, we sought to identify predictors of nodal disease on initial diagnostic pathology in nonmetastatic adenocarcinomas.

Methods: Patients with nonmetastatic appendiceal adenocarcinoma at a single institution from 1994 to 2020 were included. Clinicopathologic characteristics that predict recurrence and lymph node metastasis were analyzed. Workup included staging laparoscopy with right hemicolectomy, seriel imaging and biochemical monitoring.

Results: A total of 147 patients with mAC (18%), cAC (22%), and GCAs (59%) were included. After median follow-up of 53 months, 23 (16%) patients recurred, most commonly in the peritoneal cavity (17/23, 74%). Recurrence rates were higher among node-positive patients (59% vs. 5%, P < 0.001). Nodal disease was more common in mAC (27%) and cAC (37%) than in GCA (11%); however, adenocarcinoma grade was not associated with nodal involvement.

Conclusions: Nodal metastasis was more common in mAC and cAC compared with GCA and was the only significant predictor of recurrence in appendix cancer.