Combined detection of K-ras gene mutation in cancer tissues and carcinoembryonic antigen in serums of patients with colorectal cancer to predict liver metastasis

Objective To detected mutations of K-ras gene in cancer tissues and carcinoembryonic antigen in serums of patients with colorectal cancer,and to find out their correlation with liver metastasis. Methods The specimens of 100 patients with colorectal cancer were collected. Real-time fluorescence quantitative PCR and DNA sequencing were performed in these tissues to detect K-ras gene mutations at codon 12th and codon 13 th of exon 1 ,and carcinoembryonic antigen level in serums were evaluated by radioimmunoassay, and then the results were analyzed with patients\u0027 clinical pathological data. Results Among the 100 colorectal cancer cases,39 cases (39.0% ) were detected pointmutation,and 31 (31.0% ) cases were found pointmutation at codon 12,and 8 (8.0% ) cases at codon 13. In 36 cases with liver metastasis,23 cases (23/36,63.9%) were found K-ras gene mutations,but only 16 of 64 patients without liver metastasis were found mutated K-ras gene. The difference between the two groups was significant (P\u003c0.05).CEA level in patients with liver metastasis were (66.79±127.46) (μg/L,which was higher than that in those without liver metastasis (4.93±4.62)μg/L. Twenty-five of 36 patients with liver metastasis had a high lever of CEA,24 of 64 patients without liver metastasis did so. The positive rate of combined detection of K-ras gene mutation and CEA lever was 61.1% (22/36) in patients with liver metastasis, which was higher than that in patients without liver metastasis(5/64,7.8% ) ,P\u003c0.01. The sensitivity,specificity of combined detection of K-ras gene mutation and CEA lever in patients with liver metastasis were 61.1% and 92.2%. Conclusion K-ras gene mutation and CEA lever were closely associated with liver metastasis of colorectal cancer. Combined detection of K-ras gene mutation in cancer tissues and CEA lever in serums can predict liver metastasis of colorectal cancer.\r\n\r\nKey words: \r\nColorectal neoplasms; Ras gene; Mutation; Hepatic metastasis; CEA