Background: The aim of this study was to compare the oncologic results of abdominoperanal intersphincteric resection (ISR) and abdominoperineal resection (APR).
Methods: Between 2003 and 2014, 277 consecutive patients with stage I-III low rectal cancer located within 5 cm from the anal verge underwent curative ISR and APR. A retrospective comparison of these two procedures was performed.
Results: Overall, 128 patients underwent ISR and 149 underwent APR. The ISR group had earlier clinical stages and shorter distal margins (p < 0.01). The 5-year relapse-free survival rates in patients who underwent ISR/APR were 84.7/74.7% with T1-2 tumors and 51.3/67.6% with T3-4 tumors. In T3-4 tumors, the rate of local recurrence was higher in the ISR group (13.2%) than in the APR group (3.8%). The 5-year relapse-free survival rates in patients who underwent ISR/APR were 89.7/92.3% for stage I cases, 84.4/87.5% for stage II cases, and 39.8/51.8% for stage III cases. Patients with stage III tumors had high rates of distant recurrence in both groups (24.3 vs. 26.3%).
Conclusion: ISR is a feasible surgical procedure for T1-2 tumors. Patients with stage III tumors should be considered for adjuvant therapy to control distant recurrence regardless of the surgical procedure.
Keywords: APR; ISR; Recurrence.