Fecal blood tests-screening methods for identification of pre-tumor changes and tumors at the early stage

Abstract

Mortality due to cancer of the rectal colon is currently increasing in all groups of the adult population. Various screening methods are used to identify the pre-tumor and early stages of the development of tumor pathology of the colon: occult blood tests in feces, computer colonography (virtual colonoscopy), colonoscopy, DNA testing, tumor marker M2-PK (tumor fractional pyruvate kinase fraction M2). All of these colorectal cancer screening methods give good results, but there is no consensus among experts regarding the choice of the most optimal method. One of the first tests to detect hidden blood in the stool was biochemical tests: guaiac test (gFOBT guaiac fecal occult-blood test ), in which hemoglobin in the stool was detected by a biochemical method that exploited the pseudoperoxidase activity of hemoglobin and the Gregersen reaction, which is a benzidine test in which benzidi was used instead of guaiac resin And instead of a hydrogen peroxide barium peroxide. Enzyme-linked immunosorbent assays, in contrast to biochemical ones, use antibodies specific only to human hemoglobin, which excludes false-positive results obtained using the biochemical method. The FIT test (Fecal Immunochemical Test or Immunochemical Fecal occult blood test) specifically determines human hemoglobin in feces at lower threshold values (40300 g HB/1 g feces) compared to g-FOBT. Due to its high accuracy, Enzyme-linked immunosorbent assays are successfully used to detect occult blood in inflammatory bowel diseases, allergic enteropathies, acute intestinal infections, and erosive gastritis.