BEVACIZUMABIN AND FIRST-LINE CHEMOTHERAPY IN THE TREATMENT OF METASTATIC COLORECTAL CANCER: EVALUATION OF CLINICAL EFFICACY AND PROGRESSION-FREE SURVIVAL

The clinical effectiveness of bevacizumab in combination with FOLFIRI protocol first line chemotherapy in the treatment of advanced colorectal cancer was evaluated. Eighty patients with advanced colorectal cancer were split into two groups, one for observation (n = 40, conventional FOLFIRI chemotherapy plus bevacizumab treatment) and the other for control (n = 40, conventional FOLFIRI chemotherapy). The clinical efficacy, serum CEA (carcinoembryonic antigen) and CA19-9 (carbohydrate antigen 19-9) levels, and toxicity were compared. PFS (predicting progression-free survival) was analysed using Kaplan-Meier curves in patients with various baseline CEA and CA19-9 levels. The addition of bevacizumab to conventional FOLFIRI chemotherapy decreased the incidence of total toxicity and side effects and increased the overall response rate (ORR) and disease control rate (DCR) (p < 0.05), while decreasing the serum levels of CEA and CA19-9. Serum CEA and CA19-9 levels had a positive predictive value of 93.3%, a negative predictive value of 90.6%, a sensitivity of 84,5% and a specificity of 97.8% for the DCR evaluation when compared to Response Evaluation Criteria In Solid Tumours (RECIST) 1.1. Patients with elevated CEA and CA19-9 levels had significantly shorter PFS compared to those with normal baseline levels (p < 0.05). Bevacizumab combined with FOLFIRI as the first-line chemotherapy has excellent clinical results and has few toxic and adverse effects on patients with advanced colorectal cancer. For assessing the clinical impact of chemotherapy, serum CEA and CA19-9 levels can be used as significant auxiliary indicators. They can also be used to predict PFS in advanced colorectal cancer.