Introduction To compare outcomes of the two groups
Method National Bowel Cancer Audit Programme data from three centres,for all colorectal cancers(CRC)in the screening age group(60–74 years)over a 2 year period(August 2011–2013)were linked for their Faecal Occult Blood Testing(FOBT)screening status(BCSP database/Eastern Hub).Patient/tumour demographics and survival for Interval cancers(IC-screening patients developing cancers within 2 years of a negative FOB test)and cancers in those who declined the screening programme were analysed.All three centres were in incident rounds of screening.Tumours at and beyond splenic flexure were considered left-sided. 1 year mortality was looked at as all patients had a minimum of 1 year follow-up.
Results Of the 521 CRC identified, 127 (25%)were IC and 228 (44%)were cancers in the declined screening group.The mean age at cancer diagnosis(66.8 years vrs 67.5 years;p=0.014 ,X2= 0.33);male:female ratio(83:44vrs 130:98;p =0.024 ,X2= 2.36)and ethnic demographics(white british:others;123:5vrs211:20; p=0.090 ,X2= 2.87)between the IC and declined screening groups were comparable.Between the IC and Declined Screening groups,the tumour location(right-sided:left-sided;48:79vrs 66:162;p =0.024 ,X2= 2.36)and polyp:non-polyp cancers(2:125vrs 1:227;p =0.262 ,X2= 1.25)were comparable.
The IC had a higher proportion of advanced cancers at presentation(Dukes C/D;89 (70%)vs122(53%);p= 0.002 ,X2 = 9.28 )compared to the declined screening group.
Mortality-data 1 year mortality was 20 (16%)and 25 (11%)for the IC and declined screening groups respectively.There was no gender,age or ethnic differences between the two groups.The mortality of right-sided cancers in the IC group was significantly higher than that for the declined screening group(10 (21%)vrs 4 (6%);p= 0.037 ,X2 = 4.32 ).
Conclusion Our findings highlight that patients on the national FOBT screening programme who develop IC (specially right-sided)fared worse in the short-term, compared to CRC in patients who had declined FOBT screening-due to a higher tumour stage and a higher 1 year mortality.
Disclosure of Interest None Declared