Researchers at Duke Cancer Institute (DCI) have identified blood markers associated with tumor resistance to two common hormone therapies.
The Duke-led team reported that they isolated multiple key gene alterations in the circulating prostate tumor cells of patients who had developed resistance to abiraterone or enzalutamide.
The drug enzalutamide blocks the male androgen receptor, while abiraterone decreases testosterone levels. Both drugs are approved to treat hormone-resistant prostate cancer, but the tumors usually develop resistance within a few years.
The study used sophisticated blood analysis technology to demonstrate that tumor cells detected circulating in the blood may reveal important genetic information. This information could guide future treatment, as well as suggest possibilities for new therapies.
The DCI, in collaboration with the Duke Molecular Physiology Institute (DMPI), used a process called array-based comparative genomic hybridization to examine the genome of the circulating tumor cells within 16 men suffering advanced, treatment-resistant prostate cancer. The process allowed the team to identify which genes had extra copies and which regions were deleted.
The researchers located changes in several genetic pathways that appear to be common among the circulating tumor cells.
The noted alterations could be used as biomarkers as a part of a blood-based biopsy to determine which treatment would likely be most effective. They must first be similarly identified within larger studies. A large prospective clinical validation study is currently underway at DCI. If located, the results could direct new drug development.
Image credit: Wellcome Collection