title: Detection of tumor DNA in serum of colorectal cancer patients.
abstract: We previously found p16 promoter methylation in DNA in the sera of 13 colorectal cancer patients out of 44 (30%) whose tumor DNA exhibited the methylation, using methylation-specific PCR (MSP). To examine whether the cancer detection rate could be improved by using a different tumor marker, we examined the K-ras status in 90 colorectal cancer patients using a mismatch ligation assay. Among the 31 patients showing K-ras gene mutations in their tumors, the same mutations were observed in serum DNA of 11 patients (35%). Among the 90 patients, 63 showed tumors positive for K-ras mutation or p16 promoter methylation, or both, and 22 had serum DNA positive for one or both. K-ras mutation was found even in serum DNA of patients with Dukes A cancer, suggesting that colorectal cancer might be detected even in patients without symptoms by using this ligation assay.
authors.affiliation: Second Department of Surgery, Nagoya University School of Medicine, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ito
authors.forename: Kenji
authors.initials: K
authors.lastname: Hibi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakayama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kodera
authors.forename: Katsuki
authors.initials: K
authors.lastname: Ito
authors.forename: Seiji
authors.initials: S
authors.lastname: Akiyama
authors.forename: Akimasa
authors.initials: A
authors.lastname: Nakao
mesh_terms: D020137:Base Pair Mismatch; D015179:Colorectal Neoplasms / Q000097:blood / Q000235:genetics*; D004273:DNA, Neoplasm / Q000097:blood*; D011905:Genes, ras; D006801:Humans; D009154:Mutation
chemical_list: D004273:DNA, Neoplasm