Poland belongs to the group of countries characterized by a low incidence of colorectal cancer. However, this incidence shows a steady increasing tendency. Very low rate of success in treating large intestine cancer in our
country is mainly caused by its late diagnosis. One condition to change this situation is introduction of new methods directed at very early diagnosis apart from application of widespread screening methods: examinations for
occult blood and colonoscopy as a prophylaxis. One of the suggested methods for the diagnosis of colon cancer apart from the so far widely used methods (for example per rectum examination, tests for occult blood, tests for CEA — antigen in the serum) is the examination of the immunoreactivity of exfoliated colon cells from the feces for the presence of CD44 antigen. In this
paper we present the role of intermembranous glycoprotein CD44 which is an adhesive molecule and antigen used in the early immunodiagnosis of large intestine cancer. The expressions of CD44 and PCNA protein dependent
on the cell life cycle have been compared with a suggestion that CD44 overexpression in colon cancers is asynchronically associated with the replications of the cell. In the publication we focused on the standard
form of CD44 glycoprotein coded on the short arm of human chromosome 11 of 90 kDa molecular weight and its most common isoforms (CDv6, CDv10) observed during the course of this cancer. After the tumor resection
CD44v6 and CD44v10 levels were found to have decreased significantly. It should be emphasized that finding the above markers in the stool is a completely non-invasive method while being very helpful in the early immunodiagnosis of colorectal cancer. This study was done within Research Programme Nr 3P05B 07922, financed by KBN.

Keywords: glycoprotein CD44, colorectal cancer, immunodiagnostics