Preoperative radiotherapy and local excision of rectal cancer with immediate radical re-operation for poor responders: a prospective multicentre study.

Purpose: To assess local control after preoperative radiation and local excision and to determine an optimal radiotherapy regimen.

Methods: Eighty-nine patients with G1-2 rectal adenocarcinoma <3-4 cm; unfavourable cT1N0 (23.6%), cT2N0 (62.9%) or borderline cT2/cT3N0 (13.5%) received 5 × 5 Gy plus 4 Gy boost (71.9%) or 55.8 Gy in 31 fractions with 5-FU and leucovorin (28.1%). Local excision (traditional technique 56.2%, transanal endoscopic microsurgery 41.6%, Kraske procedure 2.2%) was performed 6-8 weeks later. If patients were downstaged to ypT0-1 without unfavourable factors (good responders), this was deemed definitive treatment. Immediate conversion to radical surgery was recommended for remaining patients.

Results: Good response to radiation was seen in 67.2% of patients in the short-course group and in 80.0% in the chemoradiation group, p = 0.30. Local recurrence at 2 years (median follow-up) in good responders was 11.8% in the short-course group and 6.2% in the chemoradiation group, p = 0.53. In the total group, a lower rate of local recurrence at 2 years was observed in elderly patients (>69 years, median value) when compared to the younger patients; 8.3% vs. 27.7%, Cox analysis hazard ratio 0.232, p = 0.016. A total of 18 patients initially managed with local excision required conversion to abdominal surgery but either refused it or were unfit. In this group, local recurrence at 2 years was 37.1%.

Conclusions: This study suggests an acceptable local recurrence rate after preoperative radiotherapy and local excision of small, radiosensitive tumours in elderly patients.