Contemporary practices in abdominoperineal resection for early-stage rectal cancer in the United States.

Aim: In contrast to significant advances in organ preservation in locally advanced rectal cancer, the contemporary management of early-stage rectal cancer, including the frequency of abdominoperineal resections, remains largely unexplored in the United States. Therefore, we assessed the utilization of neoadjuvant therapy and oncological resections in early-stage rectal cancer patients.

Study Design: This is a retrospective cohort study of patients with cT1-T3N0 rectal cancer who underwent proctectomies between 2016 and 2022 in the National Surgical Quality Improvement Project proctectomy files. Multivariable logistic regression was used to identify factors associated with abdominoperineal resections and Kendall's tau statistics to evaluate clinical-pathological staging agreement.

Results: In all, 3078 patients (29.6% cT1-2N0, 70.4% cT3N0) were included with 55.3% of tumours <5 cm from the anal verge. Overall, 58.2% received neoadjuvant therapy within 3 months of surgery (30.6% for cT1-T2N0 vs. 69.8% for cT3N0, P < 0.001), and 58.6% underwent abdominoperineal resection (55.5% for cT1-T2N0 vs. 59.9% for cT3N0, P = 0.058). The adjusted odds of undergoing abdominoperineal resection were associated with increasing age (OR 1.4 per every 10-year increase; 95% CI 1.2-1.5), cT3N0 tumours (OR 1.7; 95% CI 1.1-2.7) and tumour location <5 cm from the anal verge (OR 10.6; 95% CI 7.7-14.7). There was a weak clinical-pathological T staging correlation (Kendal tau coefficient 0.25; 95% CI 0.20-0.29).

Conclusion: In this large cohort of patients with early-stage rectal cancer with high rates of neoadjuvant therapy, over half of patients underwent abdominoperineal resection and one in five had a pathological complete response. These findings underscore opportunities for organ preservation in early-stage rectal cancer, suggesting that treatments typically reserved for locally advanced disease may extend to early stages with the completion of ongoing clinical trials.