TY - JOUR T1 - Optimization of cfDNA routine use for NSCLC genomic alteration analysis JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2016.PA3417 VL - 48 IS - suppl 60 SP - PA3417 AU - Pascale Tomasini AU - Frederic Fina AU - Clotilde Fournier AU - Laurent Greillier AU - L'Houcine Ouafik AU - Celine Mascaux AU - Fabrice Barlesi Y1 - 2016/09/01 UR - http://erj.ersjournals.com/content/48/suppl_60/PA3417.abstract N2 - Introduction: Advanced non-small cell lung cancer (NSCLC) treatment is based on molecular testing of tissue samples sometimes hard to collect, especially for old or frail patients. Cell-free tumor DNA (cfDNA) is an emerging technique and seems to be a good alternative to tumor biopsy. However, cfDNA routine use is limited by its poor sensitivity and the need to perform the analysis within 3h after blood sample collection. We studied the feasibility to extend this delay to 24h to improve the accessibility of cfDNA.Patients and methods: Stage IV KRAS mutant NSCLC patients followed in our center were selected. Two blood samples were collected and stored at 4°C. cfDNA was extracted 3h later for the 1st sample and 24h later for the 2nd sample. KRAS mutation status was analyzed using 2 techniques: conventional PCR-HRM and Sanger sequencing or droplet digital PCR (ddPCR).Results: 21 patients were selected. There was no significant difference regarding the number of DNA copies extracted after 3h or 24h (p=0.91). With conventional technique (PCR-HRM and Sanger sequencing), KRAS mutation was found for 7 (33%) patients after 3h and 24h; with ddPCR, KRAS mutation was found for 12 (57%) patients after 3h and 24h. ddPCR was more sensitive than conventional PCR. The results were the same whether DNA was extracted 3h or 24h after blood sample collection.Discussion: cfDNA extraction and analysis was feasible with conventional PCR or ddPCR 24h after blood sample collection without any sensitivity decrease. These results are important since the accessibility of this emerging technique is facilitated and may be extended to smaller centers. Moreover, ddPCR improves cfDNA analysis sensitivity. ER -