Reflecting the rapidly increasing level of research and clinical interest in liquid biopsies, May 2019 saw the first EACR–ESMO Joint Conference on Liquid Biopsies, in Bergamo, Italy.

In the opening address, Nick Papadopoulos described the possibility of achieving the ultimate goal, or ‘holy grail’ of liquid biopsy research — the use of liquid biopsies for routine screening and early detection of cancers — and this ultimate goal emerged as a common theme of the meeting. Opinions vary as to how feasible an objective this is, although a general agreement emerged among delegates regarding the need to combine measures of several different circulating biomarkers, thus emphasizing the importance of integrating research involving circulating tumour cells, epigenetic alterations, RNAs, exosomes and other circulating material, in addition to circulating tumour DNA (ctDNA), all of which were featured in this meeting.

The enormous clinical potential of liquid biopsy-based assays was discussed in detail, including sessions devoted to monitoring of tumour evolution and minimal residual disease during and after treatment. Here, emerging data from use of ctDNA-based assays to monitor acquired resistance in patients with colorectal cancer or non-small-cell lung cancer are providing early examples of the clinical implementation of this technology.

The lively panel debate on the future of liquid biopsy research was another notable highlight. Many themes emerged from this debate, including the currently limited financial incentives for the development of a circulating biomarker that might then restrict the use of a novel anticancer drug to a subpopulation of patients.

A final observation, supported by virtually all the speakers, is that many questions relating to the biology of circulating tumour material remain unanswered. The need for robust, reproducible basic science must not be overlooked in the drive towards the development of clinical assays. Indeed, such research will be essential to the many attempts to harness liquid biopsy-based technologies.

Closing the meeting, EACR president Alberto Bardelli noted that, owing to the high level of interest shown, further meetings focusing on this area of research are likely to follow shortly.