Colon-cancer screening in dialysis patients

The usefulness of colon-cancer screening using stool-guaiac testing has been established in large control populations, but not in dialysis patients. In 72 asymptomatic dialysis patients [51 treated with hemodialysis (HD), and 21 with peritoneal dialysis (PD)] who underwent outpatient stool occult blood testing, the test result was positive in 11 (15%) patients (8 HD and 3 PD). Eight of the 11 were investigated further by colonoscopy and, when deemed necessary by the treating physician, esophagogastroduodenoscopy and/or barium enema were also performed. A site of active bleeding was identified in three of the eight patients (hemorrhoids, telangiectasia, ulcerative colitis). In each of the five other patients, potentially bleeding lesions were identified: colonic polyps (two malignant and two benign) in four patients. Barrett's esophagus in one, diverticulosis in two, and colonic vascular deformities in two. These results were compared with those of a large ongoing fecal occult blood screening program in which the prevalence of positive stool occult blood tests is 5% and in which 42% of the positive patients have colonic neoplasms. Thus, although the baseline incidence of positive guaiac tests may be higher in dialysis patients than in nonuremic controls, our results suggest that stool guaiac testing of dialysis patients may not only be useful in detecting colonic polyps, but may also identify other previously unsuspected causes of gastrointestinal bleeding.