Quantification of circulating plasma DNA fragments as tumor markers in patients with esophageal cancer

The quantity and quality of circulating DNA fragments was analyzed by quantitative real-time polymerase chain reactions (qPCR) in plasma from patients with esophageal carcinomas, in order to assess their diagnostic value. Patients and Methods: Plasma was collected preoperatively from 24 patients with esophageal cancer and 21 healthy controls. qPCR was performed using two primer sets for the beta-actin gene, amplifying short and long segments. Results: The DNA concentrations in both the short and long assays of esophageal cancer patients were significantly higher than the controls (p < 0.001). The area under the receiver-operating characteristic curve was 0.83 (short) and 0.91 (long) for esophageal cancer patients versus the controls. There was also a significant difference in DNA integrity (short/long) between esophageal cancer patients and the control group (p = 0.001). Conclusion: qPCR assays for plasma DNA concentrations and their integrity can serve as new diagnostic markers for screening and monitoring patients with esophageal cancer.