Comparison of oncologic outcome of abdominoperineal resection versus sphincter saving resection for low lying rectal cancer.

PURPOSE

The present study compares the peri/postoperative and oncological outcomes of abdominoperineal resections (APR) and sphincter saving resection (SSR) for low lying rectal cancer.

METHODS

Between January 2001 and December 2014, 176 patients who underwent SSR (n=67) and APR (n=109) for low rectal cancer, without stage IV, were retrieved from a retrospective database.

RESULTS

With a median follow-up of 66.5 months. The mean total number of harvested lymph nodes was 16.7 (SSR) versus 17.1 (APR) (P=0.801). The advanced T stage was higher in the APR group (82.6%) versus the SSR group (55.2%) (P=0.006). The positive rate of lymph nodes after surgery was significantly higher in the APR group (45.9%) versus SSR group (25.4%) (P<0.05). The 5-year overall survival rates for SSR and APR were 87.3% and 67.6%, respectively (P<0.005). The 5-year disease-free survival rate (DFS) was 83.6% (SSR) versus 65.5% (APR) (P=0.002). The recurrence rate was higher in the APR group (34.9%) versus the SSR group (14.9%) (P=0.004). Local recurrence rate was not different between the two groups. However, distant recurrence rate was significantly higher in the APR group (26.6% vs. 11.9%, P=0.023). In multivariate analysis, node positive (N0 vs. N1-2) was an independent prognostic factor for DFS (P<0.005).

CONCLUSION

Based on the present data, SSR achieved better 5-year oncological outcome than APR. The positive lymph node ratio in the N stage after surgery was higher in the APR group and this seems to have an effect on the oncological outcomes of the APR group.