Could a wait and see policy be justified in T3/4 rectal cancers after chemo-radiotherapy?

Chemoradiotherapy (CRT) followed by total mesorectal excision is the standard when MRI staging demonstrates threatened surgical margins in locally advanced rectal cancer (LARC). Interest in non-surgical management of LARC as an alternative to a resection has been provoked by published excellent long-term outcomes of patients who achieve clinical complete responses (cCR) after CRT. The present retrospective study aimed to determine whether similar rates of local disease control are seen in a UK cancer centre in patients with T3-4 tumours, who obtained a cCR after preoperative CRT, but did not undergo surgery.

The outcome and treatment details of 266 patients who underwent CRT for clinically staged T3-4 rectal adenocarcinomas between 1993 and 2005 were reviewed.

Fifty-eight patients did not proceed to surgery, 10 of whom were identified as having a cCR. Six of these 10 patients subsequently developed intrapelvic recurrent disease with a median time to local progression of 20 months. Local relapse preceded the development of metastatic disease or occurred simultaneously. No patients underwent salvage resection.

CRT alone in cT3/T4 rectal cancers has a high rate of local relapse even after cCR. Delaying or avoiding surgery might be appropriate for cT1 or cT2 tumours, or elderly and frail patients with co-morbidity, but these results do not support the current uncritical move to extrapolate this approach to all surgically fit patients with rectal cancer.