Abstract
Purpose.
In recent years, the incidence of colo-rectal cancer has increased and elevated lesions of the colon and rectum have often been found in hemodialysis patients. As a screening test for colo-rectal cancer in hemodialysis patients, we applied the passive hemagglutination method which is specific to human hemoglobin.
Subjects and Methods.
Two-hundred thirty hemodialysis patients over the age of 30 years at Kojin-kai Central Hospital were studied. RPHA was performed twice on the patients who had no dietary restrictions, Examination of the lower digestive tract was conducted on those patients in whom RPHA was positive. The conventional chemical test for fecal occult blood was carried out together with RPHA.
Results
Thirty-one patients (13%) were positive in the first RPHA examination and 35 (15%) in the second one; 50 patients (21%) eventually showed positive. Thirty-one of the 50 patients were further examined. Twenty-nine lesions were found in 19 patients (one early cancer in one, 24 adenomas in 16 and four non-identifiable tissues in two). In six patients both of two RPHAs were positive, while in the remaining 13, one of two was positive. The positive rate by the conventional fecal blood test accounted for over 50% of the patients studied, suggesting that a substantial number of false-positive results due to food or drugs may be included.
Conclusions
RPHA is more reliable for the screening of colo-rectal lesions in hemodialysis patients than the conventional chemical method. Lesions were found mostly in patients on longterm hemodialysis. Therefore, RPHA, which is specific to human hemoglobin and available without dietary restrictions, is beneficial to the screening of colo-rectal lesions in hemodialysis patients. Since there are some patients who were positive only one of two RPHAs. repeated measurements are necessary.
