Local excision and chemoradiation for clinical node-negative anal adenocarcinoma

Given the lack of consensus in the surgical treatment of anal adenocarcinoma, practice-patterns demonstrate utilization of organ-preserving techniques. The adequacy of local excision compared to abdominoperineal resection (APR) as a surgical approach for stage II disease is unknown. Our study examines the utilization of local excision in the treatment of stage II anal adenocarcinoma, rates of R0 resection, and differences in overall survival compared to APR.

Using the National Cancer Database (2004-2016), we retrospectively analyzed patients diagnosed with clinical stage II anal adenocarcinoma who received chemoradiation and surgery. Patient cohorts were assigned based on the surgical procedure they received. Propensity score matching was used to offset selection bias and confounding factors. Treatment approach, pathologic margin status, and overall survival were assessed.

Overall, 359 patients underwent resection of clinical stage II anal adenocarcinoma and received chemoradiation therapy. Of these patients, 87 (24%) underwent local excision, whereas 272 (76%) received an abdominoperineal resection. In a propensity score-matched cohort, patients who underwent local excision were less likely to achieve an R0 resection (40% vs 90%), and more likely to receive adjuvant instead of neoadjuvant chemoradiation. Overall survival was not significantly different between the propensity-matched groups. Surgical approach and pathologic margin status were not independently associated with overall survival.

Among patients with clinical stage II anal adenocarcinoma who received chemotherapy and radiation, complete resection was significantly less likely with local excision compared to abdominoperineal resection, however, overall survival was not affected. Prospective studies of neoadjuvant chemoradiation followed by local excision are warranted.