Influence of Lung Parenchyma Surgical Manipulation on Circulating Free DNA

Abstract

Objectives: Metastatic recurrence is the most frequent cause of death after surgical resection of lung cancer. Manipulation during surgery has been advocated as one of the causes contributing to promotion of spreading. Methods: We investigated if the detection of plasma circulating free DNA (cfDNA) is influenced by surgical manipulation in 25 lung cancer patients (17 males and eight females) undergoing complete resection; 20 health subjects formed the control group. Bloodstream levels of cfDNA were detected before surgery, one week and one month after surgery. Results: CfDNA levels measured preoperatively and in the control group were 23 07 ± 7 4 ng/mL and 7 5 ± 3 4 ng/mL respectively (p=0 0002); levels at one week and one month were 68 2 ± 36 2 ng/mL and 9 6 ± 3 1 ng/mL respectively. The difference between the three time points were statistically significant (preop vs. one week p=0 0006; one week vs. one month p=0 0003) with an increase in the first week and a strong decrease after one month. CfDNA levels at one month were not statistically different from those recorded in the control group. There was no correlation between preoperative cfDNA levels, tumour stage, grading and histology and patient demographics. No correlation was found between postoperative cfDNA, type of surgical procedure, histology and stage. After a median follow-up of 16 months no recurrence was detected. Conclusions: Surgical manipulation determines increased cfDNA levels in the early postoperative period; however, after one month they decrease within the normal range, at levels that are statistically comparable with healthy subjects.