From guaiac to immune fecal occult blood tests: the emergence of technology in colorectal cancer screening.

Colorectal cancer is the second leading cause of cancer deaths in the United States for both men and women. Colorectal cancer screening is an important means for reducing morbidity and mortality. The American Cancer Society recommends five different screening regimens for adults of average risk, age 50 years and older. The optimal effectiveness of a screening program is dependent on the accuracy of the screening test used. An accurate screening test would have high sensitivity (positive) when an adenomatous polyp or cancer is present and high specificity (negative) in their absence. In April 2002, the American Cancer Society Colorectal Cancer Advisory Group concluded that the immunochemical fecal occult blood test has some advantages that merit revision of their guideline statement for fecal occult blood testing, to include the immunochemical fecal occult blood test. The advantages cited were the possibility of improved sensitivity and specificity and the lack of required dietary restrictions, which make it a more patient-friendly test. Several types of immunochemical fecal occult blood tests are discussed in this article, including their advantages and disadvantages compared with those of the traditional guaiac fecal occult blood testing.