Screening for colorectal cancer
===============================

* Brian Budenholzer

Sidney Winawer and Ann Zauber claim that screening for colorectal cancer with the fecal occult blood test will save 12 325 life-years per 100 000 people screened annually and that it costs less than $20 000 per life-year saved.1 I submit that neither conclusion is tenable.

For colorectal cancer screening to save life-years, lives have to be saved. However, no colorectal cancer screening trial has shown a reduction in mortality. Indeed, when the results from the 3 published randomized controlled trials of screening with the fecal occult blood test are combined they fail to show any trend toward mortality reduction: of the 137 377 patients who were screened, 25 609 died; of the 121 348 patients who were not screened, 22 158 died.2,3,4 Thus, there were 186.41 deaths per 1000 people in the screened groups and 182.60 deaths per 1000 people in the unscreened groups.

The conclusion seems unavoidable: screening with the fecal occult blood test changes the way people die, in that it modestly reduces the rate of deaths from colorectal cancer, but it fails to save lives. The published evidence fails to support the claim that any life-years are saved by colorectal cancer screening or that screening is cost-effective. Since no lives are saved, the cost per year of life saved is incalculable.

## References

1.  1. Winawer SJ, Zauber AG. Colorectal cancer screening: Now is the time [editorial]. CMAJ 2000;163(5):543-4.
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjMvNS81NDMiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTY0LzcvOTY1LjQuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. Mandel JS, Bond JH, Church TR, Snover DC, Bradley GM, Schuman LM, et al. Reducing mortality from colorectal cancer by screening for fecal occult blood. N Engl J Med 1993;328:165-71.
    
    

3.  3. Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar SS, Balfour TW, et al. Randomised controlled trial of faecal-occult-blood screening for colorectal screening. Lancet 1996;348:1472-7.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/S0140-6736(96)03386-7&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=8942775&link_type=MED&atom=%2Fcmaj%2F164%2F7%2F965.4.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1996VV46300008&link_type=ISI) 

4.  4. Kronberg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecal-occult blood test. Lancet 1996;348:1467-71.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/S0140-6736(96)03430-7&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=8942774&link_type=MED&atom=%2Fcmaj%2F164%2F7%2F965.4.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1996VV46300007&link_type=ISI)