Local recurrence rate in a national Danish patient cohort after curative treatment for rectal cancer

Several trials have shown that preoperative (chemo)radiotherapy (CRT) reduces local recurrence rates (LRRs) in rectal cancer (RC). The use of CRT varies greatly between countries. It is unknown whether the restrictive use of CRT in Denmark results in a higher LRR relative to other countries. The aim was to evaluate the LRR in a national Danish consecutive cohort of patients with RC.

All data from patients with RC in Denmark in 2009-2010 who were operated on with curative intent were retrieved from the Danish Colorectal Cancer Group database. Patients with metastases at the time of diagnosis, patients with synchronous colon cancer, and patients, in whom only local surgical procedures were performed, were excluded. In total, 1633 patients met the inclusion criteria. Clinical follow-up was at least five years with a cut-off date of 31 December 2015.

Clinical follow-up was 5.4 years (median) with an interquartile range of 4.5-6.1 years. Of all included patients, 479 (29%) were treated with preoperative long-course CRT. Local recurrence was found in 68 patients, resulting in an LRR of 4.2%, and 182 (11%) patients developed distant metastases. Five-year overall survival was 74% (95% CI: 71.64-75.91).

Five-year follow-up of curatively treated patients with RC in Denmark revealed a low LRR. This figure is identical to those reported in other Nordic countries, despite Denmark's considerably stricter guidelines for CRT. The obtained results justify the currently adopted restrictive use of preoperative CRT in Denmark.