A population-based study of radiotherapy in a cohort of patients with rectal cancer diagnosed between 1996 and 2000.

AIMS: To study, in a population-based setting, the use of delayed radiotherapy (RT) in a cohort of 2008 unselected rectal cancer patients diagnosed between 1996 and 2000.

PATIENTS AND METHODS: Radiation within 6 months of diagnosis was considered part of the primary treatment (PRT). RT given 6 months or later after diagnosis or after PRT was considered as delayed or secondary RT (SRT). Number, percentage and cumulative proportion of patients receiving SRT were calculated. The odds for receiving SRT (total and for recurrent rectal cancer only) were studied by logistic regression analysis, taking into account age, gender, co-morbidity, socio-economic status, stage, prior PRT and RT department (2 departments, each serving general hospitals only).

RESULTS: Forty-six percent of all newly diagnosed patients received RT. Ten percent (n=203) received at least once SRT, either after PRT or as first RT, of which 96 patients for a relapsed rectal tumour (31 after PRT on the rectal tumour, 65 as a first radiation treatment). In a multivariate analysis of patients with rectal recurrence secondary pelvic irradiation was less often given after primary irradiation (OR: 0.7, 95% CI: 0.4-1.1). Patients with a stage III significantly more often received SRT on a recurrence (OR=2.5, 95% CI=1.4-4.5). Generally, patients in the eastern department received more often PRT and less often SRT for recurrence (OR: 0.5, 95% CI: 0.3-0.8).

CONCLUSIONS: Five percent of all patients with rectal cancer received SRT on a recurrent tumour, with a large variation between the two RT departments in the region.