Outcomes of patients with abdominoperineal resection (APR) and low anterior resection (LAR) who had very low rectal cancer

Abstract

We compared the oncological outcomes of sphincter-saving resection (SSR) and abdominoperineal resection (APR) in 409 consecutive patients with very low rectal cancer (i.e., tumors within 3 cm from the anal verge); 335 (81.9%) patients underwent APR and 74 (18.1%) underwent SSR. The APR group comprised higher proportions of men (67.5% vs 55.4%, P = .049) and advanced-stage patients (P < .001). Preoperative chemoradiotherapy (PCRT) was more frequently administered in the SSR group (83.8% vs 52.8%, P < .001). Overall, the systemic and local recurrence rates were 29.1% and 6.1%, respectively. On stratification according to PCRT and pathologic stage, the mode of surgery did not affect the recurrence type. Moreover, recurrence-free survival (RFS) did not differ according to the mode of surgery in different cancer stages. RFS was associated with ypT and ypN stages in patients who received PCRT, while pN stage, lymphovascular invasion (LVI), and circumferential resection margin (CRM) involvement were risk factors for RFS in those who did not receive PCRT. Notably, SSR was not found to be a risk factor for RFS in either subgroup. Patients who were stratified according to cancer stage and PCRT also showed no differences in RFS according to the mode of surgery. Our results demonstrate that, regardless of PCRT administration, SSR is an effective treatment for very low rectal cancer, while CRM is an important prognostic factor for patients who did not receive PCRT.