168O - Quantification of Cell Free DNA as a Prognostic Factor in Advanced NSCLC

Abstract

ABSTRACT Purpose To investigate the prognostic importance of baseline circulating cell free DNA (cfDNA) in plasma from patients with advanced Non Small Cell Lung Cancer (NSCLC) prior to first-line chemotherapy. Material and methods The inclusion criteria were; histopathologically verified advanced NSCLC, indication for first-line chemotherapy and performance status (PS) 0-2. Treatment comprised carboplatin (area under the curve (AUC)5) iv day 1, and vinorelbine 30 mg/m2 iv day 1 and 60mg/m2 po day 8, q3w. A maximum of six courses was given. Plasma was obtained from a pre-treatment EDTA blood-sample. The number of cfDNA alleles at baseline was assessed by an in-house quantitative polymerase chain reaction (qPCR). Results A total of 246 patients were included, all receiving at least 1 course (median: 4). The overall response rate was 26%. The number of cfDNA alleles ranged from 480 to 1048500 per ml with a median value of 3200 and a 75th percentile of 6040 alleles per ml. The progression free survival (PFS) by intention to treat (ITT) was 5.4 months and the overall survival (OS) 8.9 months. The baseline level of cfDNA was strongly correlated to outcome. The median PFS was 2.9 months in patients with high levels (> the 75th percentile) compared to 5.7 months in patients with low levels ( Conclusion High levels of cfDNA seem to have a strong prognostic influence as estimated by both PFS and OS in patients with newly diagnosed advanced NSCLC. Combined with PS it outlines a group of patients with minimal or no benefit of chemotherapy, though further investigations are warranted. Disclosure All authors have declared no conflicts of interest.