Molecular genetic alteration and DNA ploidy in hereditary nonpolyposis colorectal cancer

To clarify the biologic characteristics of hereditary nonpolyposis colorectal cancer (HNPCC), an investigation was made of the association of this cancer with mutations of theTP53 (aliasp53) and K-ras genes, and with DNA ploidy. Samples from 19 patients with HNPCC and from 56 patients with sporadic colorectal cancer were analyzed by polymerase chain reaction-single strand conformation polymorphism and flow cytometric analyses. Mutations of thep53 gene were found in 7 (32%) of 22 samples from HNPCC patients, and K-ras mutations were found in 8 (44%) of 18 samples from HNPCC patients. Aneuploidy was noted in 8 (44%) of 18 samples. Each incidence in HNPCC was similar to the corresponding incidence in the sporadic colorectal cancers. The results of this investigation indicate that HNPCC shows no difference from sporadic colorectal cancer in terms ofp53 and K-ras alterations, or DNA ploidy.[PUBLICATION ABSTRACT]