Personalized
chemotherapy is the ideal treatment usually chosen to help improve the survival chances of patients with advanced
lung cancer. However, there is no short-term evaluation protocol for predicting the efficacy of the
therapy. The aim of this study was to determine the value of using plasma
DNA to monitor chemotherapeutic efficacy and to select most appropriate chemotherapeutic regimen for patients with advanced
lung cancer. Eighty-eight
lung cancer patients and 200 healthy controls were included in this study. Plasma
DNA was extracted from plasma samples with internal controls by using the BILATEST
DNA Kit. The quantity of plasma
DNA was determined by using duplex real-time quantitative PCR. After first-line
chemotherapy, plasma
DNA levels of partial response patients were significantly different from those of stable disease patients or progressive disease patients, but with no statistical difference from healthy controls (P=0.014, P<0.001 and P=0.418, respectively). Survival analysis showed a statistically better survival time in patients who had lower levels of plasma
DNA after the third cycle
chemotherapy (P=0.031). In this study, the correlation of the kinetics of
DNA concentrations with chemotherapeutic efficacy during the whole
therapy was also observed. The quantification of plasma
DNA is a sensitive
indicator of chemotherapeutic efficacy in advanced
lung cancer patients, and it can be useful in predicting response to
therapy and guiding medication.