• Colorectal cancer screening

The randomised controlled trial (RCT) of colorectal cancer screening carried out in Nottingham between 1981 and 1991 was one of a small number of pivotal studies which demonstrated the effectiveness of the Haemoccult faecal occult blood (FOB) test in reducing colorectal cancer mortality. Meta-analysis of the results of these trials provided an evidence base to support the introduction of population-based colorectal cancer screening programmes both in the UK and internationally,1 and a recent updated systematic review of follow-up data from each of the earlier studies has confirmed the reduction in colorectal cancer-related mortality.2

However, no reduction in all-cause mortality has been demonstrated in any of the trials and it has been posited that the impact of screening may be confined to ‘mortality substitution’ where those who would have died from colorectal cancer indeed did die from another cause, but without any benefit in terms of overall life years gained.3

This has led to a call for further analyses relating to the specific reasons for the deaths contributing to all-cause mortality, as well as of the mean life years gained in screened versus control populations. The study by Whynes and colleagues (see page 1088) providing updated outcomes relating to the cause and timing of death of >78 000 subjects in the Nottingham …