Screening for carcinoma of the colon: a family practice perspective.

Carcinoma of the colon is the second commonest malignancy in both sexes in North America. With little hope for a suitable method of primary prevention, physicians are forced to look for an effective secondary preventive technique. Through a collaborative effort between the physician and family practice nurse, an effective protocol for screening was developed and implemented on 355 patients aged over 40. Of these, 17 were positive. Ten of those were true positive and seven false positive. One false negative was found, but no carcinoma has been found to date-the positive patients have polyps, diverticular disease or hemorrhoids. In view of increasing evidence for the polyp-cancer sequence, this finding may be significant. Widespread use of Hemoccult II in this fashion will clarify the usefulness of this test.