Test for obscure bleeding vs colonoscopy in the prevention of colorectal cancer

Colorectal cancer is one of the most common forms of cancer and its frequency has been on the constant and significant increase over the past 20 years. Prevention aiming for early precancerous detection, results in huge financial savings in the health care system. METHODOLOGY AND TEST SUBJECTS: Prospective randomized clinical research was conducted on 150 randomly chosen asymptomatic persons over the age of 50, with positive family history. All test subjects were given a Haemoccult test and colonoscopy examination. Primary objective of the research was to detect precancerous symptoms of colorectal cancer or large intestine cancer in the early stage of the disease when it is therapeutically curable. Secondary objective was to prove that colonoscopy represents an obligatory examination of the large intestine, as well as to introduce a Haemoccult test as a regular diagnostic procedure on the level of primary and secondary health care for asymptomatic patients over the age of 50.

Out of 80/230 test subjects who did not fully complete the examination, 62 (77.5%) did not respond to the test reading for obscure bleeding, whereas 18 of them did not consent to be given a colonoscopy examination. Two registered neoplasm were found in the rectosigmoid colon, and the polyps were found in rectosigmoid colon in over 2/3 of the patients. In 125/150 test subjects, the test for obscure bleeding was negative (p < 0.001), but the colonoscopy procedure proved that 11 patients had precancerous changes (polyps). This proved that the test was not highly sensitive and it was recommended that it should be conducted in combination with colonoscopy. Patients with positive test (n = 14) had 8 normal colonoscopy results, but the difference was not significant.

Application of the test for detection of obscure bleeding once a year, in combination with flexible colonoscopy every 5 years, significantly reduces the risk of colorectal cancer inception.