Background: The National Health Service (NHS) bowel cancer screening programme (BCSP) was initiated across England in April 2006. To determine the feasibility of using national cancer registration data to assess the impact of the BCSP on stage-specific incidence, we studied trends in the incidence rates of colon (ICD10 C18) and rectosigmoid junction and rectum (ICD10 C19-C20) cancers and the completeness of data on Dukes stage in England.
Methods: Data were obtained from all nine cancer registries for the period 1996-2004, before the introduction of the BCSP, in men and women aged 50-79 years.
Results: Overall, incidence rates declined by 1% per year in the 9 years before the introduction of the BCSP (P<0.001). Dukes stage was recorded for 60% of all registrations but this varied between regions and over time. Only four registries had completeness of 74% or more. Registrations with unknown Dukes stage decreased from 1996 to 2000, and then increased during 2001-2004 affecting trends in stage-specific incidence.
Conclusion: To study the impact of the BCSP on stage-specific incidence, regional variations in data completeness need to be addressed.