Real-time monitoring efficiency and toxicity of chemotherapy in patients with advanced lung cancer

Background: The Response Evaluation Criteria in Solid Tumors (RECIST) guideline and Common Terminology Criteria for Adverse Events (CTCAE) criteria are used to assess chemotherapy efficiency and toxicity in patients with advanced lung cancer. However, no real-time, synchronous indicators that can evaluate chemotherapy outcomes are available. We wanted to evaluate tumor response and toxicity in advanced lung cancer chemotherapy by using a novel synchronous strategy. Results: We enrolled 316 patients with advanced lung cancer who were treated with cisplatin-based therapy and followed up them for 3 years. Plasma was obtained before and after every chemotherapy cycle. We quantitative assayed total plasma DNA and methylation of the APC/RASSF1A genes. Four parameters were assessed: methylation level before chemotherapy (meth(0 h)), methylation level 24 h after chemotherapy (meth(24 h)), total plasma DNA concentration before chemotherapy (DNA(0 h)), and total plasma DNA concentration 24 h after chemotherapy (DNA(24 h)). When meth(24 h) > meth(0 h) of at least one gene was used to predict tumor response, the correct prediction rate was 82.4 %. Additionally, patients for whom DNA(24 h)/DNA(0 h) <= 2 had mild toxicities. Therefore, meth(24 h) > meth(0 h) and DNA(24 h)/DNA(0 h) <= 2 were defined as criteria for better tumor response and fewer adverse events with a high correct prediction rate (84.7 %). Conclusions: Quantitative analysis of total plasma DNA and plasma APC/RASSF1A methylation provide a real-time synchronous rapid monitoring indicator for therapeutic outcomes of advanced lung cancer, which could be a reference or supplementary guidelines in evaluating chemotherapy effects.