Clinical and Pathological Properties of Patients with Metastatic Colorectal Cancer According to the RAS Mutation Status

We aimed to compare the clinical and histopathologic features at the time of diagnosis of patients with metastatic colorectal cancer according to the RAS mutation status. In this cross-sectional study, archive records of patients with diagnosing colorectal cancer who were followed-up and treated at oncology center of an university hospital in Turkey between 01.04.2012 and 24.08.2017 was analyzed retrospectively. A totally 530 patients' archive records were evaluated. The relationship between the RAS mutant/wild groups and primary tumor localization, location of metastases at diagnosis, tumor markers, tumor differentiation grade and overall survival rates were compared with the literature data. We found no statistically significant difference between RAS mutant and wild groups. When overall survival rates were compared with the RAS mutation status, the overall survival of 2 years in patients with RAS wild type was 59% while the 2 year overall survival of RAS mutant patients was 27.8% and this difference was statistically significant (p = 0.004). However, there was no statistically significant difference between the median survival of patients receiving bevacizumab or cetuksimab/panitumumab in th efirst line treatment of RAS wild patients (57.1% versus 70.7%; p=0.221, respectively). In this study, we determined that RAS mutation status of our patients with metastatic colorectal cancer is more similar to Western countries and the clinical and pathological characteristics of patients at the time of diagnosis are independent of RAS mutation status. However, there is still need broader participation and prospective trials in this subject