Background: This study was undertaken to evaluate whether genetic analysis in the stool can be useful for detecting malignant tumors in the colon and rectum. We searched for the possible presence of mutations in the p53 gene in the stool of patients with resectable colorectal cancer. Alterations in the p53 gene are the most frequent among mutant genes related to colorectal cancer.
Methods: Surgically resected tumor specimens and stool samples from 25 patients with colorectal cancer were examined for mutations of exons 5-8 of the p53 gene by polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP). Results were compared with those achieved by fecal occult blood testing.
Results: Mutations of the p53 gene were found in the tumor tissues in 11 of 25 patients (44%). Of these 11 patients, 7 (64%) had evidence of alterations in the p53 gene within the stool. Of five patients who were negative for fecal occult blood testing, p53 mutations in the stool were evident in three patients.
Conclusions: This method of stool DNA analysis for tumor-specific mutations is expected to have a wide application in clinical screening for colorectal cancer.