LAUSR

Coming of age is the transition from childhood to adulthood and, traditionally, was considered to be at 21 years. It is now 21 years since the first guaiac faecal occult blood tests (gFOBT), surrogate markers for faecal haemoglobin, were sent to eligible invitees in the UK colorectal cancer screening pilot. Following this and subsequent pilots in England and Scotland, national rollouts began in 2006 and 2007, respectively, followed by programmes in Wales and Northern Ireland. These programmes employed different screening algorithms, but all used gFOBT as the initial investigation. However, the disadvantages of gFOBT were more and more acknowledged as evidence grew concerning the merits of quantitative faecal immunochemical tests (FIT) that gave estimates of faecal haemoglobin concentration (f-Hb). Following evaluations in Scotland and England, FIT were successfully introduced into the screening programmes of the four UK nations, the main benefits being increased uptake and improved detection of colorectal neoplasia. But, further maturation of the screening programmes does seem warranted. The international recommendations are that screening should be offered to 50–74 -year-olds, but this has not been achieved to date except in Scotland. Throughout the UK, different f-Hb thresholds are used to decide the participants who would most benefit from further investigation, usually colonoscopy. Compared to other countries, these thresholds are at high f-Hb; driving down the f-Hb thresholds used would increase the colorectal cancer (CRC) detection rate (CDR) and would decrease both incidence and mortality through removal of adenoma, potential CRC precursor lesions, but this would require additional endoscopy resources. Currently, one threshold is used for all, but women are disadvantaged by this, since they have lower f-Hb, lower CDR, higher interval cancer proportions and screening has a smaller effect on CRC mortality than for men: using different f-Hb thresholds for the sexes to give the same ‘positivity’, as has been successfully introduced in Sweden and Finland, would be of advantage. It has been shown that, in screening, any detectable f-Hb (i.e. above the limit of detection (LoD)), even if lower than the threshold applied, does confer risk of future neoplasia and the risk is related to the f-Hb. It has been often suggested that screening interval might be linked to the f-Hb and participants with such results could receive different communications and advice depending on the f-Hb; these proposed strategies do not seem to have been translated into practice. Moreover, integration of f-Hb estimates into ‘risk-scores’, including data on easily obtainable data such as sex, age and deprivation status, all of which significantly affect f-Hb, and perhaps results of other investigations, has been proposed as likely to lead to improvements. Further, in screening, how f-Hb is used, if simply one of a set of variables used in the assessment of risk, may become increasingly complex if