Lower morbidity and improved outcomes in patients with screen-detected colorectal cancer.

Screening for colorectal cancer is now integrated into the fabric of healthcare systems across the world, as a wealth of evidence exists as regards its benefits in reducing cancer-specific mortality through the detection of early-stage disease. Options for screening include both endoscopic and stool-based tests, with a majority of countries opting for repeated faecal occult blood screening tests (FOBt). These can be either guaiac-based, as is the current system across the UK, or immunoglobulin-based, as is the case in the accompanying article from Spain. Patients testing positive for FOBt proceed to colonoscopy, where a relatively small proportion of patients, less than 10% in established screening programmes, will have a colorectal cancer identified. As national programmes have developed, multiple publications have focused on the differing aspects between colorectal cancers diagnosed through screening programmes (SD) and those diagnosed outside the screening pathway (NSD). In particular, patients diagnosed with SD tumours have been noted to be younger, more likely to be male and less socioeconomically deprived. Furthermore, tumour characteristics are different with early-stage disease and an absence of rectal tumours predominating in the SD patient group.