Platelets Could Improve Early and Minimally Invasive Detection of Cancer

Platelets are widely recognized for their role in blood clotting and scab formation, but they also play a crucial role in immune defense by detecting pathogens and recruiting immune cells. Beyond these roles, early cancer detection remains limited by the scarcity of circulating tumor DNA in the blood, which reduces the sensitivity of liquid biopsy techniques. New findings now reveal that platelets themselves may hold crucial information for improving diagnostics.

A study led by the Ludwig Institute for Cancer Research (New York, NY, USA) has shown that platelets absorb fragments of DNA shed by dying cells, including cancer-derived DNA. These saucer-shaped cells, though lacking nuclei, act like sponges, mopping up genetic material that would otherwise accumulate and contribute to inflammation. The discovery suggests that platelets may serve not only in immune regulation but also as powerful tools for detecting disease.

Researchers investigated the unique structure of platelets, which contain a network of membrane-lined channels known as the open canalicular system. These channels enable platelets to collect biomolecules as they circulate, including viral RNA and DNA. Inspired by this property, the team hypothesized that platelets might also capture genomic fragments, a theory supported by earlier research.

Their findings, published in Science, confirm that platelets harbor human cell-free DNA in both lab cultures and clinical samples. To rule out contamination from parent cells, scientists analyzed platelets from pregnant women and successfully predicted fetal sex by detecting Y chromosome fragments in every blood sample analyzed. Additional studies revealed that platelets also take up cancer-specific mutations, even in people with pre-cancerous polyps, highlighting their untapped diagnostic potential.

This discovery opens the door to expanding the sensitivity of liquid biopsies, which currently discard platelets during analysis. By harnessing DNA within platelets, clinicians could detect cancer earlier, improve therapy monitoring, and refine prenatal testing methods. Future research will seek to clarify the role of platelets in the physiological management of cell-free DNA and the fate and consequences of DNA fragments released upon platelet activation.

“We’ve demonstrated that platelets take up DNA fragments that bear the mutational signatures of cancer cells,” said postdoc Lauren Murphy. “This is true not only in patients with advanced cancer but, remarkably, also in people who have pre-cancerous polyps in their colon, suggesting that platelets may offer an additional and so far untapped reservoir of cfDNA that could significantly improve the sensitivity of liquid biopsies.”

Related Links:
Ludwig Cancer Research