Abstract

Background: By some estimates, colorectal carcinoma is the third most common cancer worldwide. The most appropriate method of treatment, especially of its metastatic form, is determined based on KRAS status. The present study was conducted on patients with colorectal cancer positive or neagtive for a KRAS mutation in terms of survival rate and the response to treatment. Materials and Methods: Medical records of all cases with colorectal cancer hospitalized from 2010 to 2015 and with KRAS testing results were studied. Data such as gender, age, tumor (size, grade, location, stage), treatment type, KRAS status and survival were considered as variables. Survival analysis was performed using the Kaplan-Meier method and Log-rank test. Statistical significance level was defined as P value <0.05. Results: Out of 90 patients, 55 (61.2) were male and 35(38.8) were female with the age range of 22-87 years. The overall disease specific survival was 53±3 (Mean ± SE) months with 95CI:47-60, and there were statistically significant differences between the mean survival rate with tumor stage and the response to treatment (log rank test, PV=0.007 and PV=0.001) respectively. The risk of mortality was 2.02 times higher in patients with mutant KRAS compared to those with the wild type of the gene; however, this difference was not statistically significant (OR=2.016; 95CI: 0.68-5.9; PV=0.197). Conclusions: In our study the overall 5-year disease specific survival rate was low as compared to similar studies elsewhere. Significant correlations were found between survival time with treatment type and tumor stage.