Urinary circulating DNA profiling in non-small cell lung cancer patients following treatment shows prognostic...

Disease relapse in non-small cell lung cancer (NSCLC) requires close monitoring for early detection. The aim of the current study examines the use of urinary circulating DNA for patients after first line therapies.

EGFR positive NSCLC patients in stages I-III were profiled using digital droplet PCR (ddPCR). Urinary circulating DNA was collected prior to treatment and all monitored patients had detectable EGFR mutations. Post treatment urinary DNA measurements were taken at multiple time intervals. Results were matched to disease-free survival.

Among the 213 patients recruited, 130 had matched EGFR profiles to corresponding tumor tissues. Concentrations of mutant DNA varied with different patients and mean concentration was 220±237 copies/mL. Measurements taken post-treatment showed a significant number of patients with undetectable EGFR mutations in their urine samples. Other patients registered a significant decline in urinary DNA concentrations. For measurements taken post treatment (6-month), we observed a significant increase of positively identified EGFR mutations in urine samples. In the patient group with higher urinary DNA concentration, 91% of the cohort experienced recurrence.

Our results indicated that urinary DNA measurements can potentially be useful for disease monitoring of minimal residual disease (MRD) in NSCLC. This can complement current serial radiographic imaging to provide early detection for lung cancer relapse.