Objective To investigate the changes of circulating tumor DNA (ctDNA), carcinoembryonic antigen (CEA)and carbohydrate antigen 199 levels (CA199) in patients with colorectal cancer (CRC) before and after treatment and their correlations.
Methods Thirty-eight CRC patients were selected, and were treated with radiotherapy combined with oral capecitabine for 5 weeks. The changes of ctDNA, CEA and CA199 levels before and after treatment were detected and analyzed. The correlations of ctDNA with CEA and CA199 were analyzed.
Results The levels of serum CA199, CEA and ctDNA after treatment were significantly lower than those before treatment (P < 0.05). Before treatment, ctDNA level was not correlated with CEA (r=0.005, P=0.323), and positively correlated with CA199 (r=0.365, P=0.021). After treatment, ctDNA level was not correlated with CEA level (r=-0.013, P=0.354), and positively correlated with CA199 level (r=0.318, P=0.013).
Conclusion Compared with change in CEA level, changes in ctDNA and CA199 levels are more valuable in evaluating the clinical efficacy and prognosis of CRC patients.
DownLoad: