Percutaneous transluminal coronary angioplasty (PTCA), in which a balloon catheter distends the vessel at the site of obstruction (Medical Letter, 25:97, 1983), is now an established therapeutic option for treatment of patients with coronary artery disease, especially those with single-vessel disease. Major problems related to PTCA include acute occlusion during the procedure (usually caused by dissection), restenosis at the site of angioplasty, and inability to treat complete occlusions and long or ostial lesions. Some cardiologists have tried using lasers during PTCA to deal with these...

Currently available techniques for colorectal cancer screening include fecal occult-blood testing, flexible sigmoidoscopy, double contrast barium enema (DCBE) and traditional optical colonoscopy. Optical colonoscopy requires bowel cleansing and sedation, and involves some risk, but is generally accepted as the best available method for detection of lesions and offers the advantage that polyps can be removed when they are identified. A less invasive screening tool, computed tomography (CT) colonography, also known as virtual colonoscopy (VC), offers an additional option.

Options in screening for colon cancer include fecal occult blood tests, flexible sigmoidoscopy, colonoscopy, computed tomography (CT) colonography and fecal DNA tests. Since the last Medical Letter article on this subject, more data have become available on colonography.

Most colorectal cancers arise from localized adenomatous polyps in a process that may take 10 years or more. Early detection and removal of a precancerous colonic lesion (polyp) can prevent cancer from developing.

Use of screening tests to identify cancers before they cause symptoms can lead to earlier therapy and may improve outcomes. Screening tests for some common cancers are reviewed below.