Incidence of venous thromboembolism in patients with colorectal cancer according to oncogenic status.

BACKGROUND: There are conflicting data regarding the role of KRAS mutation on the risk of venous thromboembolism (VTE) in colorectal cancer (CRC) patients. Moreover, the role of other biomarkers such as NRAS or BRAF has not been studied. PURPOSE: To analyze the incidence of VTE in a cohort of patients with CRC based on KRAS, NRAS, and BRAF status. METHODS: We performed a retrospective review of patients with unresectable locally advanced and metastatic CRC (mCRC) and known KRAS/NRAS/BRAF status, attended in the Medical Oncology Department of the Hospital General Universitario Gregorio Maranon (Madrid, Spain). The primary outcome was VTE defined as any venous thromboembolic event that occurred either 6 months before or at any time after the diagnosis of CRC. The biomarker status (KRAS, NRAS, and BRAF) and other predictors of thrombosis were collected. RESULTS: One hundred and ninety-four patients were identified and included in the analysis. Forty-one patients (21.1%) experienced VTE. The incidence was 19.1% in RAS-mutated patients, 28.6% in BRAF-mutated patients and 21% in triple wild-type patients (p = NS). In multivariate analysis, ECOG >/= 2 was the only independent predictor of VTE (OR 8.73; CI 95% 1.32-57.82; p = 0.025). CONCLUSIONS: In our study, biomarkers have not been associated with an increased risk of VTE in CRC patients. A high incidence of VTE in BRAF-mutated patients has been observed and should be explored in further studies.