Phase angle, body mass index and KRAS status of metastatic colorectal cancer in response to chemotherapy with and without target therapy: clinical impact and survival

Purpose: KRAS mutations are associated with colorectal cancer survival whereas the role of body mass index (BMI) is less defined. Phase angle, which is more an indicator of cell integrity also has not been studied as prognostic and predictive factor. We evaluated the association between BMI, phase angle and colorectal cancer overall survival (OS), by KRAS mutation status and other prognostic for metastatic colorectal cancer. Methods: This prospective study included 89 patients diagnosed with metastatic colorectal cancer in oncology and pathology departments. BMI and phase angle alpha were reported from the TANITA MC-780U mutifrequency segmental body composition analyzer at presentation at our department. KRAS mutation status was analyzed. Multivariate analysis was estimated from Cox proportional hazards models. Results: High phase angle which indicated proper cell integrity was associated with good performance status, low T stage, low fat percent and high BMI. Overall response was statistically significant with left sided colon cancer and high BMI. On multivariate analysis, the factors maintaining statistical significance with OS were KRAS and overall response. High BMI was associated with higher OS in both mutated and wild groups without statistical significance. As regard progression free survival (PFS), surgery, T stage, and lymphovascular invasion maintained statistical significance on multivariate analysis. Conclusion: High phase angle was associated with improved performance status. High BMI was associated with improved OS in all KRAS subgroups.