Colorectal cancer: implications of mass screening for public health.

The faecal occult blood test (FOBT) for colorectal cancer has a place in clinical practice in case finding, and, perhaps, in screening high-risk groups, but is it a worthwhile screening test when applied to the general population? This question is important and topical: there is increasing interest in Australia in screening by FOBT, but such a programme would be neither free of risk, nor inexpensive. We argue that there is not yet satisfactory evidence that screening by FOBT reduces mortality from colorectal cancer. There is no quicker way of learning whether FOBT saves lives than to wait for the results of the major overseas trials, the first of which should become available in the next three to five years. Until this evidence becomes available, Australia should not proceed with mass screening for colorectal cancer by FOBT. Sporadic and haphazard screening should be discouraged. What we can, and should, do now is find out more about the attitudes and behaviour of consumers and providers of screening by FOBT, the infrastructure that would be required to promote and sustain an effective mass screening programme, the total costs of colorectal cancer screening, and the performance in representative populations of new screening technologies.