Upfront Colectomy vs. Initial Appendectomy followed by Completion Colectomy for Appendiceal Cancer: A Comparison of Outcomes.

OBJECTIVE

Determine whether staged right colectomy for appendiceal cancer (initial appendectomy followed by completion colectomy - SRC) is detrimental to oncologic outcomes compared to upfront right colectomy (URC).

BACKGROUND

The decision to perform right hemicolectomy for appendiceal cancer depends on histologic features of the primary tumor. SRC allows for histologic assessment of primary tumor and may avoid an unnecessary right colectomy if not indicated.

METHODS

Stage I-III appendiceal cancer patients undergoing resection from 2000-2019 in California. Tumor histologies for which consensus guidelines recommend right hemicolectomy were included. Matched analysis was performed using 'Entropy Balancing' to compare overall survival (OS).

RESULTS

A total of 908 patients (median age 58 years; 46% female) were included of which 239 (26%) underwent appendectomy alone and 669 (74%) underwent colectomy. Of these 669 patients, 349 (52%) underwent URC, whereas 320 (48%) underwent SRC. URC (vs. SRC) was more likely to be performed for larger tumors (size >5 cm; 17% vs. 10%), high-grade disease (13% vs. 9%), and higher stage (Stage III; 10% vs. 5%) (all P<0.001). Expectedly, patients undergoing URC (vs. SRC) had worse OS (ref: SRC; Hazard Ratio [HR] 2.13; P<0.001) on univariable analysis. A subset survival analysis of elective cases with entropy balancing demonstrated that patients undergoing SRC had comparable survival to patients undergoing URC.

CONCLUSIONS

After adjusting for covariates, compared to URC, a staged approach is not detrimental to oncologic outcomes. Therefore, when possible, a staged approach should be prioritized, as it may prevent unnecessary right colectomy in many patients.