Faecal occult blood testing in the secondary prevention of colorectal cancer.

Ž . Three major randomized trials RCT have confirmed the results of a large number of case control studies, demonstrating a reduction in mortality from Ž . colorectal cancer CRC by screening average-risk Ž . persons 45 80 years annually or biennially with Ž . Ž Haemoccult-II H-II Smith Kline Diagnostics Inc., . Ž . Palo Alto, CA, USA Table 1 . The largest reduction has been obtained by the use of rehydrated H-II in Minnesota. However, this benefit was paid for by a very high rate of full colonoscopy in persons with positive H-II. The Danish study suggests that the reduction in mortality may be most pronounced in patients with CRC above the sigmoid colon, and the English as well as the Danish study suggest a more pronounced reduction in persons less than 65 years. The possibility of reproducing the results from randomized trials with Haemoccult-II in countrywide population screening programmes will be examined in the UK in two large pilot studies, and a detailed medico-technical evaluation has been performed in Denmark, suggesting that a pilot study should be set up in one or two counties. Other trials with H-II are performed in France and Sweden, but the final results are not available yet. Different types of faecal occult blood tests are available, making it possible at least to some degree to tailor the screening programme to the available colonoscopy resources. Economics suggest that in a Danish setting it would be optimal to screen 50 75year-old persons with annual H-II; this represents a more cost-effective programme than that for breast cancer and cervical cancer, although the last two cancers are detected more effectively.