Current and future opportunities for liquid biopsy of circulating biomarkers to aid in early cancer detection

Early diagnosis of cancer can significantly improve treatment and survival outcomes. Imaging and tissue biopsy are the gold standard diagnostic approaches but are costly, invasive, and often unable to detect early-stage tumors. The past decade has marked an acceleration in the discovery and development of liquid biopsy tests for aiding in the detection of various types of tumor markers in non-tissue samples, such as blood. Liquid biopsy markers include circulating tumor cells, as well as tumor cell fragments, nucleic acids, and proteins. Liquid biopsy may be useful in screening patients considered to be at high risk of developing cancer, for refining diagnosis when combined with other test results, and for early detection of recurrence. Advances in big data analytics, informatics, and artificial intelligence will make it possible to combine patient history, clinical data, and liquid biopsy marker profiles to achieve more accurate and earlier diagnosis. In this review, we summarize the current use of liquid biopsy in cancer care, including the development of multi-analyte panels to improve diagnostic accuracy and detect several cancer types in a single assay. We highlight recent advances for potential future applications of liquid biopsy to aid in the diagnosis of early-stage lung cancer. We also discuss the opportunities and challenges of integrating liquid biopsy into current algorithms for cancer screening and diagnosis

Development and analytical performance of a new ARCHITECT automated dipeptidyl peptidase-4 immunoassay

Background: Dipeptidyl peptidase-4 (DPP-4) may be a suitable biomarker to identify people with severe asthma who have greater activation of the interleukin-13 (IL-13) pathway and may therefore benefit from IL-13-targeted treatments. We report the analytical performance of an Investigational Use Only immunoassay and provide data on the biological range of DPP-4 concentrations. Methods: We assessed assay performance, utilising analyses of precision, linearity and sensitivity; interference from common endogenous assay interferents, and from asthma and anti-diabetic medications, were also assessed. The assay was used to measure the range of serum DPP-4 concentrations in healthy volunteers and subjects with diabetes and severe, uncontrolled asthma. Results: The total precision of DPP-4 concentration measurement (determined using percentage coefficient of variation) was ≤5% over 20 days. Dilution analysis yielded linear results from 30 to 1305 ng/mL; the limit of quantitation was 19.2 ng/mL. No notable endogenous or drug interferences were observed at the expected therapeutic concentration. Median DPP-4 concentrations in healthy volunteers and subjects with asthma or Type 1 diabetes were assessed, with concentrations remaining similar in subjects with diabetes and asthma across different demographics. Conclusion: These analyses indicate that the ARCHITECT DPP-4 Immunoassay is a reliable and robust method for measuring serum DPP-4 concentration. Keywords: Asthma, Automated immunoassay, Biomarker, Dipeptidyl peptidase-4, IL-1