Early detection of cancer is crucial for reducing the global burden of cancer, but effective screening tests for many cancers do not exist. A new study, published in BMJ Oncology, aimed to develop a novel proteome-based multi-cancer screening test that could detect early-stage cancers with high accuracy.

Plasma samples were collected from 440 individuals, healthy and diagnosed with 18 early-stage solid tumours. Using a proximity extension assay, more than 3,000 high-abundance and low-abundance proteins were measured in each sample. A multi-step statistical approach then identified a limited set of sex-specific proteins that could detect early-stage cancers and their tissue of origin with high accuracy.

The sex-specific cancer detection panels consisting of 10 proteins showed high accuracy for both males and females and were able to identify 93% of cancers among males and 84% of cancers among females, with 99% specificity. In addition, the sex-specific localisation panels consisted of 150 proteins and were able to identify the tissue of origin of most cancers in more than 80% of cases. The analysis of the plasma concentrations of proteins selected showed that almost all the proteins were in the low-concentration part of the human plasma proteome.

The authors concluded that the proteome-based screening test showed promising performance compared with other technologies and could be a starting point for developing a new generation of screening tests for the early detection of cancer. While further validation in larger population cohorts is necessary to establish the reliability and generalisability of the findings, they say the results provide a foundation for future research and emphasise the potential of proteomic analysis in revolutionising cancer diagnosis at the population level.