Abstract 3145: Clinical evaluation of streck cell-free DNA blood collection tubes for liquid profiling in oncology

Liquid profiling based on circulating tumor DNA (ctDNA) extracted from blood has become a powerful diagnostic approach in oncology. Making ctDNA analysis broadly available requires shipping whole blood to a clinical laboratory while ensuring cell-free DNA (cfDNA) and blood cell integrity to prevent dilution of ctDNA with cellular genomic DNA. Since standard EDTA blood collection tubes cannot retain this integrity for a prolonged time, several laboratories have proposed Streck Cell-Free DNA blood collection tubes (Streck cfDNA BCTs) as an alternative for sample collection. Qualification data for the use of Streck cfDNA BCTs in oncology is limited and mainly based on blood collected from healthy individuals as well as data extrapolated from the prenatal field. However, the data generated from these samples may not represent the unique dynamics of clinical oncology specimens and therefore a study of true clinical oncology samples is required to support the use of Streck cfDNA BCT tubes in routine practice. In this study, we performed a clinical evaluation of cfDNA sample integrity from matched Streck cfDNA BCTs vs standard EDTA tubes from colorectal, pancreatic and non-small cell lung cancer patients (N > 50). Blood drawn into Streck cfDNA BCTs was either processed immediately or 3 days after phlebotomy. DNA quantification was followed by BEAMing digital PCR (OncoBEAM™) on KRAS, NRAS and EGFR mutations and compared to matching specimens collected in EDTA tubes. Our results suggest that cfDNA yield as well as the genomic DNA background is not affected by prolonged storage of clinical samples in Streck cfDNA BCTs for up to 3 days. In all sample sets containing mutated ctDNA, the detected mutational load was comparable between Streck cfDNA BCTs and EDTA tubes. In conclusion, this study represents a comprehensive clinical evaluation of Streck cfDNA BCTs vs EDTA tubes for ctDNA profiling. In conjunction with the findings of our previously presented Streck cfDNA BCT shipping condition studies, our data supports the compatibility of clinical oncology specimens collected in Streck cfDNA BCTs with the BEAMing technology. Citation Format: Inga Medina Diaz, Stefan Holdenrieder, Annette Nocon, Makbule Kobilay, Dirk Skowasch, Stefanie Held, Johanna Weiland, Claudia Stamm, Frank Diehl, Frank Holtrup. Clinical evaluation of streck cell-free DNA blood collection tubes for liquid profiling in oncology. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3145.