Longitudinal Analysis of Local Recurrence and Survival After Transanal Abdominal Transanal Radical Proctosigmoidectomy for Low Rectal Cancer Treated With Neoadjuvant Chemoradiation Therapy

BACKGROUND: The transanal abdominal transanal radical proctosigmoidectomy was developed in 1984 as a sphincter preservation surgery in patients with low rectal cancers after preoperative radiation therapy. While serving as a catalyst for disruptive sphincter preservation surgery, it continues to be used and evolve. With the controversy over safety and local recurrence in other sphincter-preserving surgery, review of transanal abdominal transanal radical proctosigmoidectomy long-term oncologic outcomes is warranted. OBJECTIVE: To assess local recurrence and survival after transanal abdominal transanal radical proctosigmoidectomy after neoadjuvant chemoradiation therapy. DESIGN: Retrospective cohort study of a prospectively maintained database. SETTINGS: Tertiary rectal cancer referral center. PATIENTS: Patients with low adenocarcinoma (=5 cm anorectal ring) receiving neoadjuvant chemoradiation therapy and then transanal abdominal transanal radical proctosigmoidectomy for curative resection between 1998 and 2021. MAIN OUTCOME MEASURES: Local recurrence rates and overall survival rates. RESULTS: Of 255 included patients, 67.8% were men (n = 173); the mean age was 58.7 years (SD 11.5) and the mean BMI was 27.1 (SD 5.4), with 50.2% (n = 128) having ASA class II and 49.8% (n = 127) having ASA class III/IV. The mean tumor size was 4.8 cm (SD 1.9), the majority of patients had clinical T3 disease (81.8%; n = 184), and 52.1% had nodal disease (n = 100). The median radiation dose was 5400 cGy, with 73.7% (n = 149) achieving good response and 90.2% (n = 230) receiving minimally invasive surgery. The complete total mesorectal excision rate was 94.3%, and 100% of patients (n = 255) had negative distal margins. The mean number of examined lymph nodes were 13.9 (SD 10.7). After a median follow-up of 55.4 months, 5.1% of patients (n = 13) developed local recurrence at a median time of 29.6 months. The 5-year overall survival was 84.1% (95% CI, 78.889.4). LIMITATIONS: Retrospective review with risk of bias and lack of generalizability. CONCLUSIONS: In this longitudinal study, the transanal abdominal transanal radical proctosigmoidectomy demonstrated excellent long-term locoregional control and survival in very low rectal cancers. The superior transanal abdominal transanal radical proctosigmoidectomy outcomes are durable over time, warranting expansion of the sphincter-preserving surgery technique. See Video Abstract.