Serum Uric Acid Level May Be a Predictive Factor for BRAF V600E Mutation in Older Patients with Metastatic Colorectal Cancer: An Exploratory Analysis.

ABSTRACT

INTRODUCTION: This study aimed to show the relationship between the serum uric acid level measured at diagnosis and the BRAF mutation status in the primary tumor tissue in patients with metastatic colorectal cancer. METHODS: In this retrospective cross-sectional study, 264 patients (64% male) whose serum uric acid level was measured at the time of diagnosis and whose BRAF mutation status in the primary tumor was determined were included. RESULTS: The BRAF mutation rate was 14% (n = 37). The median serum uric acid levels of all patients were 6.9 mg/dL (25%, 75% percentile range 3.7, 8.2). The serum uric acid level cut-off value was 6.6 mg/dL. Sensitivity and specificity for BRAF mutated patients were 84% and 27%, respectively. These rates were calculated as 85% and 70% in BRAF-mutated patients aged 65 and over. There was a significant correlation between BRAF mutation and high serum uric acid level, female gender, tumor located in the ascending colon, and multiple metastatic sites. The independent factors affecting BRAF mutation were age 65 and over, tumor in the ascending colon, and high serum uric acid level. CONCLUSION: As a result, we concluded that high serum uric acid level measured during diagnosis in metastatic colorectal cancer is an accessible and economical biomarker that can predict BRAF mutation in patients aged 65 and over.