Energetics and lifestyle in inherited syndromes (ELLIES Project): Feasibility of remote specimen collection for biomarker analysis.
Authors: Venkatesh Priyanka , Knight Catherine J. , Klemp Jennifer R. , Puri Rajni V. , Pathak Harsh B. , Bloomer Clark , Nye Lauren Elizabeth 
Published: June 2023

e22545 Background: Hereditary breast cancer (BC) impacts ~39,000 individuals annually and about 10% of BCs result from an inherited mutation. Obesity is independently associated with an increased risk of BC and there is interest in studying modifiable risk factors such as nutrition, obesity, and physical activity in correlation to risk, but there is a paucity of data on the impact of lifestyle on risk and less is known about biomarkers specific to lifestyle interventions and mutation carriers. Biologic pathways are implicated in the association of obesity and cancer risk and several biomarkers have been adequately measured in fingerstick samples in controlled settings but not studied in remote specimens. To characterize metabolic risk factors and lifestyle habits over the lifetime and inform a future intervention, we explored the feasibility of obtaining sufficient specimens for biomarker analysis using home collection kits within a cohort of hereditary cancer mutation carriers. Methods: Cohort 1, recruited from a prospective registry of mutation carriers were mailed a home biospecimen collection kit containing a bloodspot collection card (BCC), a lancet for fingerstick blood collection, a tube containing a nucleic acid stabilizing buffer for saliva collection, return postage, and detailed instructions. Cohort 2, recruited from a High-Risk BC Clinic, provided a fasting intravenous blood draw and fingerstick for a BCC. Dried BCCs were analyzed for biomarkers: leptin, IGF-1, IGF binding proteins 1 and 2, glucose, and CRP. Variances between biomarker levels in home kits and plasma samples were examined. Saliva samples were evaluated for miRNA and SNPs. Results: 40 individuals were invited to participate in Cohort 1; 20 enrolled within 7 days and were mailed a kit; ~14 days occurred between mailing the kits and receiving specimens; 5 participants (25%) were unable to fill all circles on the BCCs, 1 (5%) was unable to draw blood with the lancet provided; 5 participants (25%) required additional postage and 5 (25%) were lost to follow-up. Rate of return of completed biomarker kits was 70% (15), with only one incomplete. 11 clinic patients were invited to participate in Cohort 2; 10 enrolled and provided a fasting intravenous blood draw and fingerstick for a BCC. Pearson coefficients between plasma samples and matching dried BCC samples indicated good correlations for most markers (leptin r = 0.97, p = 0.001; IGFBP1 r = 0.98, p = 0.001; IGFBP2 r = 0.97 p = 0.001; glucose r = 0.97, p = 0.003; CRP r = 0.98, p = 0.001; IGF1 r = 0.39, p = 0.30. Of the remote saliva collections, 14 of 15 samples had adequate quality and quantity of gDNA for SNP analysis and miRNA for miRNAseq. Conclusions: Remote self-collection of capillary blood and saliva was well-accepted in a cohort of hereditary mutation carriers and feasibility was established as specimens were adequate for measuring defined biomarkers.