Circulating tumor cells (CTCs) – cancer cells shed from tumors to the bloodstream – are some of the most studied liquid cancer biomarkers and offer enormous predictive and prognostic potential. But their rarity and heterogeneity as resulted in a plethora of isolation and detection methods aiming to expand their clinical utility.

In a collaboration with the University of Copenhagen, Rigshospitalet, the Herlev and Gentofte Hospitals, VARCT Diagnostics reports the use of rVAR2 – our proprietary recombinant VAR2CSA which specifically binds oncofetal chondroitin sulfate (oncofetal CS) – to detect CTCs directly in blood samples from two diverse cancer patient cohorts, bypassing the need for CTC enrichment or separation technologies.

In a first cohort of patients with advanced cancer – those that have exhausted standard of care treatment – we showed that rVAR2 was able to detect 7 out of the 11 cancer types. Critically, this included those for which current CTC strategies remain suboptimal, such as non-small cell lung cancer, urothelial carcinoma, ovarian carcinoma, and glioblastoma. Also important, no CTCs were detected in blood samples from 13 healthy donors. We subsequently explored the use of rVAR2 to detect CTCs in a second cohort of patients with no cancer diagnosis but reporting serious non-specific symptoms or signs of cancer. Here we showed that rVAR2 could detect CTCs in 57% of cases also independently diagnosed with cancer.

The detection of ofCS on CTCs across diverse cancer types and disease stages highlights the broad clinical utility of CTCs. This study demonstrates the potential of our tumor-agnostic CTC diagnostics platform to expand the applicability of CTC liquid biopsies to a wider range of cancers while reducing sample handling and costs.

We are deeply grateful to the patients for donating samples and to the Innovation Fund Denmark for supporting this effort as part of a Grand Solutions.

Read more about it here: https://www.nature.com/articles/s41698-025-00936-3