Analysis of circulating tumor DNA in plasma at diagnosis and during follow-up of lung cancer patients

We evaluated whether the amount of circulating DNA in plasma could discrimi nate between lung cancer patients and healthy individuals and whether it is related to disease progression, and we analyzed the kinetics of plasma DNA in disease-free, surgically resected patients. Plasma DNA quantification a nd analysis of microsatellite alterations were performed in a consecutive s eries of 84 patients with non-small cell lung cancer, who were studied duri ng follow-up, and 43 healthy controls. In patients, the mean values of plas ma DNA concentration were higher than in controls even considering stage Ia patients. Sensitivity and specificity estimates were calculated as the are a under the receiver operating characteristic curve (AUC-ROC) curve and sho wed a value of 0.844, Variations in DNA level and in microsatellite changes correlated with the clinical status of 38 patients monitored during follow -up. The data suggest that quantification and molecular characterization of plasma DNA in lung cancer patients are valuable noninvasive diagnostic too ls for discriminating patients from unaffected individuals and for detectin g early recurrence during follow-up.