Selective use of preoperative radiotherapy in the treatment of cancer in the lower two thirds of the rectum

PURPOSE: The authors review the result of the selection of patients with a low rectal cancer for pre-operative radiotherapy. METHODS: The selection was based on the findings of digital examination eventually combined with surgical staging consisting of bimanual palpation during a staging laparotomy or "trial" operation. This selection was used to divide the patients into three groups: one where local radicality could be expected from primary surgery (group 1), one with deeply infiltrating, but mobile tumours requiring 10 x 3 Gy pre-operative radiotherapy (group 2) and one with fixed or borderline resectable tumours requiring protracted pre-operative radiotherapy with 55-59 Gy (group 3). One hundred and one patients were eligible for this study. A resection aiming for pelvic radicality was carried out in 94 patients: primary resection in 38 (group 1), surgery subsequent to 10 x 3 Gy pre-operative radiotherapy in 20 (group 2) and 55-59 Gy in 36 (group 3). RESULTS: The calculated risk of local recurrence at 5 years was 15% (95% C.I. 4-27) for group 1, 8% (95% C.I. 0-20) for group 2 and 30% (95% C.I. 16-44) for group 3. The calculated 5 years survival for the 3 groups was respectively 60%, 49% and 39%. CONCLUSION: The overlap in local recurrence rate between the three groups suggests a substantial downgrading by this approach of selective use of pre-operative radiotherapy in the patients with the most advanced tumour. Notwithstanding recent improvements of imaging techniques there still is a place for the staging laparotomy in the selection of the treatment strategy for advanced rectal cancers