Evaluation of long-term oncological outcomes of inter-sphincter resection compared with abdominoperineal resection for treatment of ultra-low rectal cancers: a single center 5-year experience.

Objectives: Abdominoperineal resection (APR) is considered the gold standard surgical treatment for ultra-low rectal cancer. Anus-preserving alternative procedures have been tested to avoid the need for a permanent colostomy. The present study compares the functional and oncological outcomes of the traditional APR methods with inter-sphincteric resection (ISR). Methods: Sixty patients with ultra-low rectal cancers that underwent tumor resection using the ISR and APR methods were compared retrospectively. Patients' demographic information as well as tumor characteristics were evaluated. All patients were followed after the operation every three months for two years, and then every six months for at least three years. Results: Thirty-four (56.6%) patients were male, and 26 (43.3%) were females, which showed no statistical significance between the two groups. The mean tumor distance from the anal verge in the APR group was 5.11±0.06 cm and in the ISR group was 5.22±1.1 cm. In the APR group, 9 (30%) patients developed primary tumor recurrence, while in the ISR group, 10 (33.3%) patients had relapses. The observed difference was not statistically significant. However, the study showed that patients with a T stage of T2 or higher had a higher probability of tumor recurrence. Conclusion: There is no significant difference in the efficacy of the ISR method compared with the conventional APR for the treatment of ultra-low rectal cancer.