Prostate cancer is often fatal, but a new gene study might show the way to treating 90 percent of patients. Recognizing genetic markers for the disease could permit the development of precision medicine for men suffering from the disease, according to the international study.
Arul Chinnaiyan and Charles L. Sawyers of the Stand Up to Cancer-Prostate Cancer Foundation Dream Team headed the research. Their team examined DNA and RNA in prostate cancer samples collected from 150 patients, which were donated by eight institutions in the U.S. and Europe. The samples came from tumors with metastatic castration-resistant prostate cancer, an advanced form of the disease that has stopped responding to standard hormone treatments. It is extremely difficult to treat patients at this stage using conventional methods.
"One of the surprising findings in this study was that approximately 90 percent of cases harbored some kind of genetic anomaly that was clinically actionable, meaning we have potential treatments to target that specific aberration," Chinnaiyan said. "This suggests that clinical genomic sequencing could impact treatment decisions in a significant number of patients with disease."
Prostate cancer is the second leading cause of death for men across all 50 states, taking one life every 18 minutes. A new diagnosis of prostate cancer occurs every 2.4 minutes.
Earlier studies have examined the genomes of various forms of prostate cancer, only to find few genetic targets for future forms of treatment. The large selection of samples in this study made it possible to identify segments of genetic code that could be utilized for treatment.
Around two-thirds of the samples were revealed to have mutations in receptors for androgen, a group of hormones. Researchers believed they would find this kind of a mutation, given the inability of hormones to treat these cases of prostate cancer.
"One avenue for treatment of patients diagnosed with prostate cancer is the reduction of androgen hormones, such as testosterone and dihydrotestosterone, by chemical or surgical means. However, as with most hormone dependent tumors, prostate cancer becomes resistant to hormone-deprivation therapy," Stand Up to Cancer stated in a post.
The BRCA1 or BRCA2 genes were found to be mutated in 14 percent of samples. Changes to this section of the genetic code were already known to increase the risks from ovarian and breast cancers. New treatments, known as Parp inhibitors, have already been approved for BRCA-positive ovarian cancers, and they could hold promise for treatment of prostate cancer.
Future research will examine genetic samples from 500 patients, and follow the progress of the disease over the course of several years.
This study was published in the journal Cell.
Photo: Lisa Brewster | Flickr
