OC-115 Comparison of screen detected and interval colorectal cancers in the bowel cancer screening programme: experience from the North East of England

Introduction The NHS Bowel Cancer Screening Programme (BCSP) commenced screening in North East England in February 2007. It offers biennial faecal occult blood testing (FOBt) followed by colonoscopy for those with a positive FOBt. All cases of colorectal cancer (CRC) known to the MDTs in this region are registered with the Northern Colorectal Cancer Audit Group (NORCCAG) database. Methods CRCs occurring in the screening population (aged 60–69 years) between April 2007 and March 2010 were identified from the NORCCAG database. Their screening history was obtained by cross-referencing this database with the regional BCSP database. Cases were classified into four groups: a control group (cancers diagnosed prior to first screening invite), screen detected, interval (cancers diagnosed between screening rounds after a negative FOBt) and non-uptake (patients who declined screening). Patient demographics, tumour characteristics and survival were compared between the four groups. Results 1336 CRCs were diagnosed in the screening population. 511 (38.2%) cancers were in the control group. 825 cancers (61.8%) were detected in individuals who had been invited for screening. 322 (39.0%) were screen detected, 311 (37.7%) were in the non-uptake group and 192 (23.3%) were interval cancers. All of the interval cancers followed a negative FOBt. Compared to both the control group and the interval cancer group, the proportion of males in the screen detected group was significantly higher (73.0% vs 62.4% & 60.4%, χ 2 =9.88, p=0.002 and χ 2 =8.77, p=0.003 respectively). Screen detected cancers were more likely to be left sided than in the control or interval cancer groups (78.6% vs 70.1% & 66.7%, χ 2 =7.32, p=0.007 & χ 2 =8.89, p=0.003). Significantly more Dukes A and fewer Dukes D cancers were found in the screen detected group compared to the control and interval groups (p 2 =50.36, p 2 =53.62, p Conclusion This is one of the first studies that provides data on the performance of the BCSP in one region since its national implementation. The FOB test is better at detecting cancers in the left colon and in men. There are significant numbers of interval cancers, which were not found to have an improved outcome compared to the non-screened population as has previously been published. Competing interests None declared.