The role of VEGF and other parameters in tracking the clinical course in metronomic chemotherapy.

The purpose of this study was to investigate the effect of metronomic chemotherapy on serum vascular endothelial growth factor (VEGF) levels in cancer patients. The study included 11 metastatic cancer patients who received daily 50 mg cyclophosphamide and biweekly 5 mg methotrexate per os as metronomic chemotherapy. Bevacizumab together with FOLFIRI chemotherapy was administered as anti-angiogenic treatment in another group of 16 metastatic colorectal carcinoma patients. Furthermore, VEGF levels of 10 healthy individuals and 5 cord blood samples served for comparisons. VEGF levels of patients before therapy and 3 months after treatment were analyzed and compared. Serum VEGF levels prior to metronomic chemotherapy were higher compared with the healthy controls (p=0.0001). Similarly, serum VEGF levels prior to the bevacizumab-based chemoimmunotherapy were significantly higher compared with the healthy controls (p=0.005). In patients on metronomic chemotherapy VEGF levels showed non significant decrease (p=0.075). On the contary, VEGF levels decreased significantly (p=0.002) with bevacizumab treatment. Serum VEGF levels may be used for assessing of the efficacy of anti-angiogenic therapies.