Colorectal; cancer.

Kathy Whayman, MSc, DipN, RN, is a lecturer at the Burdett Institute of Gastrointestinal Nursing with King's College London and St Mark's Hospital, Harrow.

Colorectal cancer is the second most common cause of cancer death, with a five-year survival rate of about 50%.1 It is more common in individuals over the age of 50 and the average age at diagnosis is 70.2 More than 35,000 new cases are diagnosed in the UK each year, but incidence is increasing as the population ages. There is also evidence of an increasing age-specific incidence, particularly among men aged between 65 and 84, to which lifestyle and environmental factors are thought to contribute.2 Most colorectal cancers evolve from polyps, which can develop over many years to form adenocarcinomas. Two-thirds occur in the colon, with the remainder in the rectum, and although incidence of colon cancer is the same for both sexes, rectal cancer is more common in men.3 Diagnosing colorectal cancer is changing rapidly, and involves both primary and secondary care.

Risk factors Two rare specific genetic syndromes cause colorectal cancer: familial aden-omatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), although clusters of the disease can also occur in families with neither of these conditions.2 Those with close relatives diagnosed with colorectal cancer are at increased risk, so establishing family history is essential. In response to the rapidly increasing research base on the role of cancer genetics in this disease, there is a current emphasis on setting up services and clinics to provide genetic screening and counselling. These are often led by specialist nurses. People with ulcerative colitis account for around 1% …