**Preface to "Cancer Biomarkers in Body Fluids"**

Over the next 20 years, a sharp rise in cancer cases is expected, increasing from 18.1 million people diagnosed in 2018 to an expected 29.5 million people in 2040 (Global Cancer Observatory; WHO). Cancer burden can be reduced by promoting prevention campaigns, increasing early detection, and implementing personalized cancer therapies. In such a scenario, the identification of circulating biomarkers in body fluids is emerging as a breakthrough in cancer diagnostics for the relative ease of obtaining biological samples using minimally invasive procedures before, during, and after cancer treatment; additionally, the availability of groundbreaking technologies which perform high-throughput and informative biomolecular analyses on limiting sample amounts is boosting biomarkers screening studies. Recently, several scientific publications have provided proof of principle studies which show the great advantage of using circulating biomarkers to monitor exposure to cancer risk factors, increase the accuracy of cancer screening protocols, and detect actionable therapeutic targets. Liquid biopsy shows promise for cancer screening and diagnostics, though some technical challenges still remain.

> **Fabrizio Bianchi** *Editor*
