This thesis analyses the impact of the NHS Bowel Cancer Screening Programme (BCSP) since its national implementation. A regional cancer registry (Northern Colorectal Cancer Audit Group, NORCCAG, database) and the regional BCSP database were combined to obtain the full screening history for all patients diagnosed with a colorectal cancer (CRC) in the North East of England, out of the population eligible for screening.
The CRCs in the screening population between April 2007 and March 2010 were identified and classified into four groups: control (diagnosed before first screening invite), screen-detected, interval (diagnosed between screening rounds, after a negative screening episode), and non-uptake (declined screening). Patient demographics, tumour characteristics and survival were compared between groups.
In all, 511 out of 1336 (38.2%) CRCs were controls; 825 (61.8%) were in individuals invited for screening of which 322 (39.0%) were screen-detected, 311 (37.7%) were in the non-uptake group, and 192 (23.3%) were interval cancers. Compared with the control and interval cancer group, the screen-detected group had a higher proportion of men, left colon tumours, and superior survival, implying the guaiac-based faecal occult blood test (FOBt) is more effective at detecting cancers in these groups. There was no difference in demographics, tumour location/stage, or survival between control and interval groups.
A cost-effectiveness analysis of altering the screening pathway by lowering the minimum criteria for an abnormal FOBt was performed and raises potential opportunities that the screening programme could develop in order to minimise on the number of missed cancers
