BODY MASS INDEX AS A PROGNOSTIC FACTOR FOR DISEASE PROGRESSION IN PATIENTS WITH METASTATIC COLORECTAL CANCER TREATED WITH BEVACIZUMAB BASED SYSTEMIC THERAPY.

CONTEXT: Epidemiological data have shown that obesity increases the risk of developing colorectal cancer and also an increased body mass index (BMI) is associated with a worse prognosis. Bevacizumab based systemic therapy, an antiVEGF targeted therapy, is an important treatment option for metastatic colorectal cancer (mCRC) patients. Obesity is associated with high level of vascular endothelial growth factor (VEGF), that might provoke resistance to antiVEGF monoclonal antibody.
OBJECTIVE: To evaluate the efficacy in terms of progression free survival (PFS) and overall survival (OS) of bevacizumab systemic therapy in patients with mCRC.
DESIGN: Retrospective cohort, single center study. SUBJECTS AND METHODS: Between January 2007 and December 2012, 112 patients with mCRC, who followed bevacizumab based systemic therapy in the "Ion Chiricuta" Oncology Institute in Cluj-Napoca, were included in our analysis.
RESULTS: Values of BMI ≥ or <27 kg/sqm was found that PFS is statistically significant superior in patients with BMI<27 kg/sqm (n=77) than in those with BMI ≥ 27 kg/sqm (n=35), 24 months versus 17.9 months (p = 0.04). Five years OS was not influenced by the BMI, 35% vs 30% (p=0.29). In patients with liver metastases with values of BMI ≥ 27 kg/sqm have PFS lower than patients with a BMI <27 kg/sqm, 17.5 months versus 24.5 months (p = 0.02). Five years OS was not influenced by the BMI, 39% (BMI <27 kg/sqm) vs. 22% (BMI ≥ 27 kg/sqm) (p = 0.09).
CONCLUSIONS: This study demonstrated the negative influence of BMI on both PFS on the entire sample of patients and in patients with liver metastases only, BMI cut-off value proved to be 27 kg/square meter and shows that the BMI may be an important prognostic factor with a high clinical relevance in patients with mCRC.