Colonic screening is a hot topic these days, and rightly so.
Colorectal malignancy is a major cause of cancer deaths, yet most cases are preventable.
The majority of cases evolve insidiously from benign adenomatous polyps, which typically grow slowly and silently for several years before they turn malignant. There have been a few proponents of this viewpoint, but until recently the idea seemed too radical to seriously contemplate. The higher prevalence in Lieberman's study may partly reflect the inclusion of subjects at greater risk because of a family history of colon cancer, but nevertheless it is clear that a significant minority of asymptomatic individuals harbour dangerous colonic polyps or early malignancy. In an editorial appearing in the same issue of the journal, Daniel Podolsky 11 concludes that it does and states, as others have as well, that sigmoidoscopic screening is as illogical as examining only 1 breast with mammography to screen women for breast cancer. Although catchy, this is an invalid analogy because colonoscopy is a far more complex exercise than sigmoidoscopy.