Colorectal cancer is one of the most significant causes of cancer death. A genetic model for colorectal cancer has been proposed in which the sequential accumulation of mutations in specific genes, including adenomatous polyposis coli (APC), Kirsten-ras (K-ras), and p53, drives the transition from healthy colonic epithelia through increasingly dysplastic adenoma to colorectal cancer. APC(Adenomatous polyposis coli) gene mutation and hypermethylation occur early, and lead to dysplasia or formation of a polyp, followed by K-ras mutations, in the K-ras gene, it grows at a faster rate resulting in a benign Class I adenoma. DCC (Deleted in colon cancer) and p53 genes mutations lead to late adenoma and finally carcinoma. The most common combination of mutations was p53 and APC (27.1%), whereas mutations in both p53 and K-ras were extremely rare. We examined 35 cases with colon cancer APC and p53 gene mutations. In this study, we used polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses to detect APC gene mutation (nucleotide 1876-codon 641-exon 11, and nucleotide 5241-codon 1764-exon 15) and p53 gene mutation (codon 72 exon 4 and intron 6,exon7) with  colon cancer cases.  

Tissues were collected from 35 cases with  colon cancer  ages of female 40-90(mean age 65.95±2.76) and ages of male 40-79(mean age 61.67±3.07). Genomic DNA was extracted from parafin embedded tissues using EZNA Tissue DNA Kit (Omega) protocol. We used Standard PCR-RFLP methods. The informativity for  PCR-RFLP was 21(75.0%) for RsaI polymorphism in exon 11 and 22 (88.0%) for Bbv12I polymorphism in exon 15 for APC gene. The informativity for PCR-RFLP was 27 (77.1%) for BstFNI polymorphism in exon 4 and 30 (85.7%) for BstHHI polymorphism in exon 7 for p53 gene.

As a result; although combination of mutations APC and p53 may be present in carcinoma, but combination of mutation  APC and p53 may not be early adenoma. The loss of APC and p53 genes by mutation and deletion seems to be a marker for the conversion of adenoma to carcinoma, and may be using as prognostic indicators of tumor behavior and survival in patients with colorectal cancer.