Immunological detection of occult blood in bowel cancer patients

Abstract

Summary The ability of a highly sensitive gel immunodiffusion technique to detect faecal occult blood in control subjects and in patients with colorectal carcinoma, was compared to that of Hemoccult II. In 1,200 samples from 200 control subjects, 3.3% were positive by the immunological technique, 5.0% by Hemoccult II with rehydration and 2.3% without rehydration, representing 7.5%, 10.5% and 5.0% of subjects, respectively. A total of 2 carcinomas and 6 polyps were detected in the 27 positive subjects. (Doran & Hardcastle, 1982). The proportion of false negative results can be diminished by using kits of higher sensitivity or by preliminary rehydration of the faecal specimens, but both give an increased proportion of false positive results (Frommer & Logue, 1981;Winawer et al., 1980 Materials and methods SubjectsTwo hundred members of the general public (aged 61.6 +10.2y) who agreed to take part in bowel cancer screening studies and 40 patients with colorectal carcinomas (aged 67.0+12.1y), collected 6 faecal smears on filter paper from six bowel actions for immunological testing. During the last three bowel actions, Hemoccult II cards (containing two sample windows for each bowel action, giving a total of 6 samples per card) were also used. In order to reduce the numbers of false positive results with Hemoccult II, the subjects were asked to abstain from eating red meat (but chicken and fish

Sensitized immunochemical method for the specific detection of human haemoglobin in dried biological samples

“…Furthermore, ELISA has not been found to be a suitable mass screening method for occult colorectal bleeding because of high positivity and expenses (5,14,24,31).…”

“…Colour reactions based on peroxidase activity such as the conventional benzidine-and guaiac-type reactions are not specific to human Hgb; many times they yield false results. So it has been proposed that some immunological methods to detect human Hgb be introduced in both fields of medicine (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(25)(26)(27).…”

Effective Screening for Bowel Cancer: A United Kingdom Perspective

“…The use of Hemoccult (Smith Kline Diagnostics Incorporated, Sunny Vale, CA), a guaiac-impregnated paper test requires special diets, 80 but can be positive in 90 percent of cancers that bleed >30 ml per day. 81 The other forms of this test, which detect blood using immunologic techniques, [82][83][84][85] are more difficult and currently more expensive.…”

The pros and cons of fecal occult blood testing for colorectal neoplasms

“…Since then other immunologic approaches to occult blood detection have been devised, and a burgeoning number of methods have been published [88][89][90][91][92][93][94][95][96]. These vary considerably in technical details.…”

“…Most studies reveal positive results in about two-thirds of patients with known malignancy [56,68,89,126]; by using repetitive testing and rehydrated slides a sensitivity as high as 90% can be achieved [68]. Immunologic tests for occult blood have even greater clinical sensitivity, with abnormal results reported in about 75% to over 90% of patients with known bowel cancer 189, [92][93][94]96]. Early results with the HemoQuant test are equally impressive; almost all patients with colorectal cancer can be detected if 2 mg Hgb/g stool is uscd as the cutoff point [53].…”