Association between proto-oncogene mutations and clinicopathologic characteristics and overall survival in colorectal cancer in East Azerbaijan, Iran.

BACKGROUND

Colorectal cancer (CRC) is the third-most common cancer in Iran. The increasing incidence of CRC in the past three decades has made it a major public health burden in the country. This study aimed to determine any relationship of specific mutations in CRCs with clinicopathologic aspects and outcome of patients.

MATERIALS AND METHODS

This study was conducted on 100 CRC patients by the case-only method. Polymerase chain-reaction products were analyzed by Sanger sequencing, and sequence results were compared with the significant and gene mutations in the My Cancer Genome database. Logistic regression models were used to detect associations of clinicopathologic characteristics with each of the mutations. Kaplan-Meier and Cox regression models were constructed to estimate overall survival in patients.

RESULTS

A total of 26 subjects (26%) had heterozygote-mutant , and mutations were not detected in the amplified exon of in both tumor and normal tissues of the 100 CRCs. Rectal tumors had 1.53-fold higher likelihood of mutations than colon tumors, and men had 1.37-fold higher odds than women. The presence of metastasis increased the likelihood of mutations 2.36-fold over those with nonmetastatic CRCs. Compared to patients with wild-type cancers, those with mutations had significantly higher mortality (hazard ratio 3.74, 95% confidence interval 1.44-9.68; log-rank =0.003).

CONCLUSION

Better understanding of the causality of CRC can be established by combining epidemiology and research on molecular mechanisms of the disease.