Regional differences in local recurrence rates after rectal cancer surgery

Aim To analyse a substantial regional difference in local failure rate after rectal cancer surgery focusing on management. Method National, population-based, prospective registry data were used, including comprehensive 5-year follow up of 3783 patients operated on in the period 1998-2000. Local recurrence rates were compared using crude rate, Kaplan-Meier estimates and competing risk methodology. Resected patients (651 regional and 3132 national) were analysed and subgroup comparisons of management were performed. Results The crude local recurrence rate was 13.7% in the regional cohort and 7.1% in the national cohort. The absolute difference of 6.6% may partly be explained by systematic errors of underreporting (<= 1.4%), differences in patient populations and indications for surgery. A significant difference in the use of neoadjuvant radiotherapy (explaining <= 1.0%) and some aspects of surgical strategy were also observed. Conclusions We conclude that some of the difference in the registered incidence of local recurrence between the regional and the national cohorts remains unexplained and may depend on surgical technique in terms of lack of radicality in removing tumour tissue.