Population screening for colorectal cancer

Each year in the UK, around 16,000 people die from colorectal cancer. At disease presentation, around 55% of people have advanced cancer that has spread to lymph nodes, metastasised to other organs or is so locally advanced that surgery is unlikely to be curative (Dukes' stage C or D). Overall 5-year survival for colorectal cancer in the UK is around 47-51% (compared to 64% in the USA), but only 7% at most in those presenting with metastatic disease. These facts underlie the current introduction of national bowel screening programmes in the UK. Here we assess the role of screening of the general population in reducing mortality from colorectal cancer. We do not consider the screening arrangements needed for high-risk populations, including those with inflammatory bowel disease or a strong family history of colorectal cancer.