ABSTRACT:
KRAS gene mutations in codon 12 are detected remarkably in high occurrence in Iraqi patients with colorectal adenocarcinoma. This study aims to investigate the mutations in codon 12 of this gene in colorectal tumor specimens. Fresh biopsies samples were collected from one hundred and twenty colorectal cancer (CRC)patients and one hundred (ulcerative colitis) as non-malignant negative control for revealing mutations in KRAS (codon 12) using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR), mutations were compared between patients and negative control, clinicopathologic features (age, gender, tumor size, grade, stage and tumor site) were compared between mutated and wild-type KRAS in CRC patients. Heterozygous mutations in KRAS codon 12 were significant only in individuals with CRC 52 of 120 (43.33%) when compared with non-malignant control group (ulcerative colitis) 0 (0%) (P<0.001), Odd ratio was 1.765; 95% CI was (1.765-2.202), other CRC patients were present in wild-type homozygotes 68(56.66%). High mean age, well-moderate grade, stage II and recto-sigmoid tumor was significant in association with heterozygous KRAS mutation in codon 12 than homozygous wild-type of CRC patients (P<0.05). Mutation in codon 12 KRAS is regarded as aprognostic marker used for early diagnosis of CRC, also it determines which patient responds to anti-EGFR targeted antibodies treatment.