A national cohort study of long-course preoperative radiotherapy in primary fixed rectal cancer in Denmark

Preoperative radiotherapy has been shown to enable a fixed rectal cancer to become resectable which in turn may result in long-time survival. In this study, we analysed the outcome of long-course preoperative radiotherapy in fixed rectal cancer in a national cohort including all Danish patients registered with primary inoperable rectal cancer and treated in the period May 2001 to December 2005.

The study was based on surgical and demographic data from a continuously updated and validated national database. In addition, retrospective data were retrieved from all departments of radiotherapy concerning technique of radiotherapy, dose and fractionation and use of concomitant chemotherapy. Outcome was determined by actuarial analysis of local control, disease-free survival and overall survival.

A total of 258 patients with fixed rectal cancer received long-course radiotherapy (> 45 Gy). The median age at diagnosis was 66 years (range: 32-85) and 185 (72%) patients were male. The resectability rate was 80%, and a R0 resection was obtained in 148 patients (57% of all patients and 61% of those operated). The 5-year local recurrence rate for all patients was 5% (95% CI: 3-7%), and the actuarial distant recurrence rate was 41% (95% CI: 35-47%). The cumulative 5-year disease-free survival was 27% (95% CI: 22-32%) and overall 5-year survival was 34% (95% CI: 29-39%).

This study is the first population-based report on outcome of preoperative long-course radiotherapy in a large unselected patient group with clinically fixed rectal cancer. Most patients could be resected with the intention of cure and one in three was alive after 5 years.