c-Ki-ras mutations in colorectal adenocarcinomas from a country with a rapidly changing colorectal cancer incidence.

摘要: We have examined the incidence of mutation c-Ki-ras proto-oncogene in colorectal adenocarcinomas from two different time periods, namely 1962–1966 and 1994–1996. The first cohort samples consisted formalin-fixed, archival paraffin block represent oldest cancer for which ras has been examined, while second tumours were fresh, flash-frozen representative genetic events occurring contemporary times. Analysis status was undertaken by a mismatch-specific oligonucleotide hybridization analysis exon 1 after amplification polymerase chain reaction. Mutations codon 12 or 13 detected 28% (14/50) samples, figure consistent with locally established rates. In contrast no any 18 earlier period, result that is statistically significant (P = 0.007). Age-standardized rates Singapore seen marked increase over last 30 years, we shown such an associated, at least part specific mutagenic change. © 1999 Cancer Research Campaign