[The application of p53 gene mutation status in fecal specimen in the diagnosis of colorectal carcinoma].

OBJECTIVE: To explore the value of analysis of p53 gene mutation in fecal specimen in the diagnosis of colorectal carcinoma (CRC) in order to establish a non-invasive method for the screening of CRC.

METHODS: The status of p53 gene mutation of the tumor tissues and corresponding fecal specimens was analyzed by polymerase chain reaction-single strand configuration polymorphism with EB staining in 40 CRC, 20 colorectal adenoma and 15 gastrocarcinoma.

RESULTS: Amplification rates of fecal p53 gene were 90%, 85% and 93% in 40 CRC, 20 colorectal adenoma and 15 gastrocarcinoma, respectively. Total amplification rate was 89%. p53 gene mutation in tumor tissue was detected in 29 of 40 cases of CRC, 23 cases of which had p53 mutation in fecal specimens with the diagnostic sensitivity rate of 57.5%. Analysis of fecal p53 gene mutation had relatively higher diagnostic sensitivity rate than the detection of serum carcinoembryonic antigen and fecal occult blood (P < 0.05) for the diagnosis of CRC. 3 of 20 colorectal adenoma had p53 mutation both in tumor tissues and fecal specimens. 10 of 15 gastrocarcinoma had p53 mutation in tumor tissues but none in fecal specimens.

CONCLUSIONS: Analysis of fecal p53 gene mutation has relatively higher diagnostic sensitivity rate for diagnosis of CRC and is expected to be a relatively sensitive, specific and effective method for early diagnosis of CRC, especially for CRC screening in large scale of the population.