Analysis of Ki-ras and p53 gene mutations in laterally spreading tumors of the colorectum

• Published in: Pathology international 2003-12, Vol.53 (12), p.828-836
• Main Authors: Noro, Akihiro, Sugai, Tamotsu, Habano, Wataru, Nakamura, Shin-ichi
• Format: Article
• Language: English
• Subjects: Adenoma, Villous - genetics; Adenoma, Villous - pathology; Adenoma, Villous - surgery; Adult; Aged; Aged, 80 and over; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Colorectal Neoplasms - surgery; colorectum; DNA Mutational Analysis; DNA Primers - chemistry; DNA, Neoplasm - analysis; Female; Genes, p53; Genes, ras; genetic heterogeneity; Humans; Ki-ras; laterally spreading tumor; Male; Microdissection; Middle Aged; Mutation; p53; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational
• ISSN: 1320-5463; 1440-1827
• DOI: 10.1046/j.1440-1827.2003.01564.x

A laterally spreading tumor (LST) is considered to be a specific subtype of superficial colorectal tumors, in view of its characteristic clinicopathological features. We attempted to compare genetic alterations found in LST (>10 mm) with those found in IIa‐type adenomas (10 mm or less (small superficial elevated lesion)) and conventional polypoid adenomas (>10 mm). In addition, multiple sampling by microdissection was performed for 14 LST to examine genetic heterogeneity in the Ki‐ras and p53 gene mutation patterns. Polymerase chain reaction, single‐strand conformation polymorphism and direct sequencing were used to analyze Ki‐ras and p53 gene mutations in 73 sporadic colorectal adenomas: 28 LST; 22 IIa‐type adenomas; and 23 polypoid adenomas. Ki‐ras gene mutations were found more frequently in LST (6/28 tumors) and polypoid adenomas (6/23 tumors) than in IIa‐type adenomas (2/22 tumors), although this difference was not statistically significant. The frequency of p53 gene mutations in the 28 LST was 25% (7/28), which was significantly higher than that found in IIa‐type adenomas (P