Several series report higher recurrence after transanal excision of T1 rectal cancer than after radical resection. However, the impact of transanal excision on cancer mortality has not been adequately studied. The purpose of this study was to compare oncologic outcomes of transanal excision with those of radical resection.

Patients with transanal excision or radical resection for T1 rectal cancer treated between 1985 and 2004 were identified from a prospective database. Patients receiving preoperative chemotherapy or radiation or with tumors >12 cm from the anal verge were excluded.

The final cohort comprised 145 radical resections and 137 transanal excisions. The transanal excision group was notable for older mean age (64 vs. 59 years), shorter mean distance from anal verge (5.9 vs. 7.8 cm), and smaller tumor size (2.3 vs. 3.1 cm). Lymphovascular invasion and poor differentiation were similar in both groups. Twenty percent of radical resection specimens had lymph node metastasis. Median follow-up was 5.6 years. Local recurrence was noted in a higher proportion of transanal excision patients (13.2 vs. 2.7 percent, P = 0.001). After transanal excision the hazard ratio for local recurrence was 11.3 (95 percent confidence interval, 2.6-49.2), and disease-specific survival was inferior (87 vs. 96 percent at 5 years, P = 0.03, hazard ratio 2.8 [range, 1.04-7.3]).

Transanal excision offers inferior oncologic results, including greater risk of cancer-related death. This procedure should be restricted to patients who have prohibitive medical contraindications to major surgery or have made an informed decision to accept the oncologic risks of local excision and avoid the functional consequences of rectal resection.