Comparing blood collection tubes for the prospective BrOvED study for early detection of cancer in women at high risk of breast and ovarian cancer

Wendy Cooper ^1,2 Patricia Harrington ³ Craig Luccarini ³ Irena Hudecova ^1,2 Andreia Ribeiro da Silva ⁴ Daniel Barrowdale ⁵ Debra Frost ⁵ Karen Pooley ⁵ Heather Machado ⁶ Jamie Blundell ⁷ Joanna Baxter ⁴ Alison Dunning ³ Charles Massie ⁷ Elizabeth Moore ^1,2,8 James D. Brenton ^1,2,7 Douglas Easton ⁵ Nitzan Rosenfeld ^1,2

¹Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
²Cancer Research UK Cambridge Centre, University of Cambridge, Cambridge, UK
³Centre for Cancer Genetic Epidemiology, Department of Oncology, University of Cambridge, Cambridge, UK
⁴Cambridge Blood and Stem Cell Biobank, Department of Haematology, University of Cambridge, Cambridge, UK
⁵Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
⁶Wellcome Trust, Sanger Institute, Hinxton, UK
⁷Department of Oncology, University of Cambridge Hutchison–MRC Research Centre, University of Cambridge, Cambridge, UK
⁸Department of Obstetrics and Gynaecology, University of Cambridge, Cambridge, UK

Developing a test for earlier cancer detection requires sample collection from a very large number of participants to observe sufficient incident cancers for meaningful analyses. As part of the BrOvED programme for breast and ovarian cancer early detection we will, in the primary care setting, collect annual blood samples from women with a substantially elevated risk of breast and/or ovarian cancer. We expect to recruit ~4400 women with a strong family history or a known pre-disposing mutation conferring high risk of these cancers. Over the 5-year study we expect to observe 160 incident breast cancers and 100 ovarian cancers in this population.

To support analysis of circulating tumour DNA (ctDNA) and other markers from blood collected in the primary care setting, appropriate tube types must be used that can retain quality of cell-free DNA (cfDNA). Samples will be returned by post and based on data from the current long running EMBRACE study we expect ~80% to arrive within 3 days, and more than 99% within 7 days. Several commercial tubes claim to preserve cfDNA during postage for these periods.

In this sub-study, we aim to compare tubes from multiple commercial providers. For 4 healthy donors we collected blood in tubes from deltaDNA Biosciences, Nonacus, Norgen, PAXgene, Roche and Streck. The tubes were posted, and processed 3 days after blood draw. These were further compared to samples collected in EDTA tubes and either posted or immediately processed. We recorded cell viability, plasma volume recovery, evidence for haemolysis, cfDNA yield (by digital PCR) and size profile (by Tapestation and shallow whole genome sequencing (sWGS)). Sequencing error profile and ability to undergo bisulphite conversion will be presented along with cell viability and genomic DNA yield from the same blood draw.