Unexpected rectal cancer after TEM: outcome of completion surgery compared with primary TME.

BACKGROUND

Transanal endoscopic microsurgery (TEM) has gained wide-spread acceptance as a safe and useful technique for the resection of rectal adenomas and selected T1 malignant lesions. If the lesion appears >T1 rectal cancer after resection with TEM, a completion TME resection is recommended. The aim of this study was to investigate the results of TME surgery after TEM for rectal cancer.

METHODS

In four tertiary referral hospitals for TEM, all patients with completion TME surgery after initial TEM were selected. All eligible patients who were treated with 5 × 5 Gy radiotherapy followed by TME surgery from the Dutch TME trial were selected as reference group. A multivariate logistic regression model was used to calculate odds ratio's (OR) for colostomies and for colo- and ileostomies combined. Local recurrence and survival rates were compared in hazard ratio's (HR) using the multivariate Cox proportional hazard model.

RESULTS

Fifty-nine patients were included in the TEM-COMPLETION group and 881 patients from the TME trial. In the TEM-COMPLETION group, 50.8% of the patients had a colostomy compared to 45.9% in the TME trial, OR 2.51 (p < 0.006). There is no significant difference when ileo- and colostomies are analyzed together. In the TEM-COMPLETION group, 10.2% developed a local recurrence compared to 5.2% in the TME trial, HR 6.8 (p < 0.0001).

CONCLUSIONS

Completion TME surgery after TEM for unexpected rectal adenocarcinoma results in more colostomies and higher local recurrence rates compared to one stage TME surgery preceded with preoperative 5 × 5 Gy radiotherapy. Pre-operative investigations must be optimized to distinguish malignant and benign lesions and prevent avoidable local recurrence and colostomies.