Local excision after radio(chemo)therapy for rectal cancer: is it safe?

According to current opinion, local excision in rectal cancer should be limited to selected T1N0 tumours. Preoperative radio(chemo)therapy provides an opportunity for expanding the use of local excision for more advanced tumours. The key rationale of this approach is the correlation between the radiosensitivity and inherited low aggressiveness of rectal cancer and the correlation between the radiosensitivity of the primary tumour and the radiosensitivity of mesorectal nodal disease. This allows for a selection of local excision for radiosensitive tumours or conversion to abdominal surgery in radioresistant cases. Eleven reports including a total of 311 patients treated with preoperative radio(chemo)therapy and local excision have been published. In some series, the tumours were initially large and unresectable by the transanal approach. Pathological data suggest that local excision must involve all tissue invaded on pre-treatment examination with a margin, even in patients with a clinical complete response. The pooled analysis has shown a local recurrence rate of 1% (1/83) for patients achieving a pathological complete response, 8% (3/40) for ypT1, 11% (4/37) for ypT2 and 3/9 for ypT3. In conclusion, the results of preoperative radio(chemo)therapy and local excision are encouraging and warrant a population-based, multicentre controlled study.