Distinctive clinicopathological features of Ki-ras mutated colorectal cancers

• Published in: Journal of surgical oncology Vol. 94; no. 3; pp. 234 - 241
• Main Authors: Lin, Jen-Kou, Chang, Shih-Ching, Wang, Huann-Sheng, Yang, Shung-Haur, Jiang, Jeng-Kai, Chen, Wei-Chone, Lin, Tzu-Chen, Li, Anna Fen-Yau
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.09.2006
• Subjects: Aged; Calcium - blood; Chi-Square Distribution; colorectal cancer; Colorectal Neoplasms - blood; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; DNA Mutational Analysis; Female; folate; Folic Acid - blood; Gene Frequency - genetics; Genes, ras - genetics; Humans; Ki-ras; Male; Middle Aged; Mutation; Neoplasm Invasiveness; Neoplasm Staging; Prognosis
• ISSN: 0022-4790; 1096-9098
• DOI: 10.1002/jso.20438

Background and Objectives We explored the relationship between the mutation pattern of Ki‐ras and the clinicopathological features of colorectal cancers (CRCs). Methods Relationships between clinicopathological parameters and Ki‐ras mutation status were analyzed in 255 CRC patients using the chi‐square and student t‐tests. Kaplan‐Meier survival curves were compared using the log‐rank test. Results Ki‐ras mutation occurred in 43.9% of tumors, and 83% affected codon 12. The most frequent mutations were GGT‐>GAT (Gly‐>Asp) (37.5%), followed by GGT‐>GTT (Gly‐>Val) (31.3%), both in codon 12. The frequency of Ki‐ras mutation was similar for different tumor stages (38.2–47.8%). The mucin component of tumors was significantly associated with Ki‐ras mutation. The 4‐year overall and disease‐free survival was 61% and 54%, respectively, for patients with Ki‐ras mutated tumors, and 73% and 60% for patients with nonmutated tumors (not statistically significant). Patients with Ki‐ras mutated tumors had lower plasma folate (24 ng/dl) than those bearing nonmutated tumors (37 ng/dl). Patients with G‐>T Ki‐ras mutations had the lowest folate level (22 ng/dl), followed by those with G‐>A mutations (25 ng/dl). Conclusions Ki‐ras mutated colorectal tumors have a higher mucin production and higher differentiation, and are associated with lower plasma folate levels and a relatively poorer disease outcome. J. Surg. Oncol. 2006;94:234–241. © 2006 Wiley‐Liss, Inc.