Circulating bone marrow cells predict prostate cancer outcomes

A study^[1]
has found that the increased presence of a type of bone marrow cell called a megakaryocyte in the blood indicates a more favourable prognosis in people with prostate cancer.

The research team showed that by combining information on the number of circulating tumour cells (CTCs) and megakaryocytes, they were able to predict that some patients with advanced prostate cancer had a ten-fold increased risk of death.

The researchers studied blood samples from 81 patients with prostate cancer, 28 who had localised untreated disease and 43 with progressive treatment-resistant and, in most cases, metastatic disease.

The aim of the study was to see if the detection of mesenchymal CTCs could be used as a predictive biomarker in prostate cancer. These are tumour cells that have undergone epithelial-mesenchymal transition, a key process in cancer metastasis that is associated with invasiveness and resistance to therapy.

They found that the number of mesenchymal CTCs was associated with high-risk localised disease and metastasis and were a better predictor of the latter than prostate-specific antigen level, which is routinely used for prostate cancer diagnosis and monitoring.

The team also incidentally discovered that an increased number of megakaryocytes showed a trend towards increased survival. When they combined information on both mesenchymal CTCs and megakaryocytes to create a score for each patient with metastatic disease, they found that the 16 patients with the highest scores were 10 times more likely to die than the 24 patients with the lowest scores.

Writing in Clinical Cancer Research, they say the role of megakaryocytes in cancer progression needs further study, but the results indicate that they could become a new prognostic biomarker in metastatic prostate cancer.

Dr Yong-Jie Lu, reader in medical oncology at Barts Cancer Institute, London, says: “The discovery of the role of megakaryocytes in patient blood as a favourable 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.”