Utility of urinary circulating tumor DNA for EGFR mutation detection in different stages of non-small cell lung cancer patients.

PURPOSE: Non-invasive methods of molecular profiling for non-small cell lung cancer (NSCLC) are useful for monitoring disease progression. The aim of the current study was to ascertain if transrenal DNA is sensitive for clinical correlation and EGFR detection in NSCLC patients.
METHODS: 160 patients at various stages of the disease participated and samples were collected prospectively at 2-month intervals. A baseline sample was taken before treatment commencement. To ascertain the sensitivity of transrenal DNA, we compared its results with plasma DNA. ddPCR was used to profile the urine and blood samples for key EGFR mutations.
RESULTS: Using tumor tissues as references, our study showed good concordance in EGFR mutations with transrenal DNA before treatment. Results were highly matching in late-stage NSCLC patients, with stage III/IV patients yielding an agreement of more than 90%. The assay was also sensitive to detect early-stage patients after surgical procedures. Profiles were highly concordant with results derived from plasma DNA, demonstrating the specificity of transrenal DNA assays. Serial monitoring of these patients showed stable molecular signatures and correlated to different treatments. Survival analysis showed good prognostic utility for late-stage patients with high transrenal DNA variations and patients that acquired T790M mutation.
CONCLUSION: The study demonstrated the feasibility of using transrenal DNA in mutation profiling for different stages of NSCLC patients. It highlights the importance of continual monitoring and has potential clinical utility in the clinical management of NSCLC.