NEW YORK (GenomeWeb) – Circulating tumor cells (CTCs) and rare, large, blood platelet-producing bone marrow cells called megakaryocytes may provide clues to disease outcomes in individuals with prostate cancer, new research suggests.
After searching for strategies to better distinguish between CTCs and other cell types in the blood, investigators from the UK and China explored potential ties between CTC and other circulating cell subtypes and disease outcome in 43 individuals with castration-resistant prostate cancer and 38 more individuals with untreated, localized prostate cancer.
The team's results, published online yesterday in Clinical Cancer Research, led to circulating cell types that were enhanced in those with decreased survival time, more aggressive tumors, and/or an enhanced disease burden. In particular, megakaryocytes appeared to be present in higher than usual amounts in patients with better prognoses, while poorer outcomes tended to coincide with a rise in cells showing signs of epithelial-to-mesenchymal transition (EMT).
"The discovery of the role of megakaryocytes in patient blood as a favorable prognostic biomarker has the potential to open up new avenues of research in the fight against cancer, not only in prostate cancer, but potentially other cancers too," corresponding author Yong-Jie Lu, a molecular oncology researcher with Barts Cancer Institute at Queen Mary University of London, said in a statement.
The study, which was funded in part by the liquid biopsy firm Angle PLC, used that company's epitope-independent Parsortix CTC isolation system to track circulating cells in blood samples from 81 prostate cancer patients enrolled at St. Bartholomew's Hospital in London. The microfluidics-based cell capture approach differs from CTC capture technologies already approved by the US Food and Drug Administration, which typically target specific circulating cell expression profiles.
Based on the cells isolated in blood samples from these individuals, the researchers found that prostate cancer metastasis could be best predicted by combining prostate specific antigen profiles from the blood with information on the levels of CTCs with EMT-associated expression patterns. From those data, they reportedly predicted prostate cancer metastases with around 92 percent accuracy.
On the other hand, an uptick in overall megakaryocyte levels in the blood — and a shrinking mesenchymal cell-to-megakaryocyte ratio — appeared to correspond to better survival in the patients profiled.
"We have already started to test more patient samples and will soon move on to wider clinical trials to confirm the efficacy of the [Parsortix system-based] test," Lu said. "We are also working to see if this test can be used on other types of cancer."