The risks of screening: data from the Nottingham randomised controlled trial of faecal occult blood screening for colorectal cancer

Abstract

Aims-To determine the harm that ensues from faecal occult blood (FOB) screening for colorectal cancer. Methods-150 251 people were randomly allocated either to receive biennial Haemoccult FOB tests (n =75 253) or not to be contacted (n=74 998). Study group patients returning positive tests were oVered colonic investigation; 1774 underwent complete investigation of the colon. Results-There was no significant diVerence in the stage at presentation of interval versus control group cancers. Survival in the interval cancer group was significantly prolonged compared with the control group. Sensitivity for colonoscopy or flexible sigmoidoscopy and double contrast barium enema (DCBE) was 96.7%. There were no complications of DCBE but seven (0.5%) complications of colonoscopy, of which six required surgical intervention. There were no colonoscopy related deaths. No patients without colorectal cancer died within 30 days of colonic investigation. Five patients died within 30 days of surgery for screen detected colorectal neoplasia and a further two died without having surgery. Six patients died after 30 days but within two years of surgery for screen detected benign adenomas or stage A cancers; in all cases the cause of death was not related to colorectal cancer. Conclusions-There was investigation related morbidity but no mortality and little to support overdiagnosis bias. The group returning falsely negative tests had a better outcome compared with the whole control group. There is a negative side to any screening programme but mortality reduction in this and other trials suggests that a national programme of colorectal cancer screening should be given consideration. (Gut 1999;45:588-592)

Colonoscopic screening and follow-up for colorectal cancer in the elderly

“…In this study 87% of the patients suffered from multiple organ diseases such as heart disease, encephalopathy, and nephrosis, and 24.3% of them had diseases in more than 3 vital organs, but the incidence of complication was significantly lower than that (0.4-1.4%) [29][30][31] with no occurrence of death and perforation [31] as a result of the improvement of intestinal canal preparation, simplification of colonoscopy intubation, and the appropriate measures taken for them according to the changes of their blood pressure and ECG when colonoscopy was performed. 29.2% of the patients in this study had a history of abdominal operation, but the successful rate of intubation was 98.9%.…”

Colorectal cancer screening

“…Four randomized controlled trials have investigated the effect of gFOBT screening on CRC mortality, and the results have been presented in nine reports ( [17][18][19][20][21][22][23][24][25]). Three of the trials [17][18][19][20][21][22][23]25] used repetitive, multiple screening rounds with FOBT (either annually or biennially), whereas the Swedish trial only offered two screening rounds (at the start of the trial period) with a 2-year screening interval [24].…”

“…Three of the trials [17][18][19][20][21][22][23]25] used repetitive, multiple screening rounds with FOBT (either annually or biennially), whereas the Swedish trial only offered two screening rounds (at the start of the trial period) with a 2-year screening interval [24]. Figure 3 shows a meta-analysis of data from the four randomized trials of the effect of repetitive FOBT screening on CRC mortality.…”

Alternatives to colonoscopy for population-wide colorectal cancer screening

“…76,77 Combining double-contrast barium enema with flexible sigmoidoscopy When DCBE was combined with FS, they had the same sensitivity for cancer as colonoscopy (96.7%). 78 Two RCTs in the 1990s reported a lower detection rate for small polyps for FS plus DCBE when compared with colonoscopy. 79,80 Nonetheless the detection rate for cancers and large polyps was comparable.…”