Most Aggressive Prostate Cancers May Not Respond to ADT, Research Finds
Emergent research has discovered evidence that androgen deprivation therapy (ADT), a common hormone therapy for patients diagnosed with prostate cancer, may not be as effective against the most aggressive strains of prostate cancer.
Topping the Gleason Score
If you know anything about prostate cancer, you’re likely familiar with the Gleason Grading System. Knowing a patient’s Gleason score can, essentially at a glance, help you understand just how aggressive their prostate cancer is likely to be; lower numbers are better, with the most aggressive forms of prostate cancer being reserved for Gleason scores of 8 through 10.
When you have a high-scoring prostate cancer, treatment for that cancer is going to be more aggressive. This includes radiation therapy, surgery, or hormone therapy in the form of ADT. Unfortunately, new research has discovered that while cancers with a Gleason score of 8 respond well to ADT, Gleason 9 and 10 cancers seem to receive little to no benefit from this widely-used therapy.
The Problem with ADT
Researchers discovered, according to their data, that using androgen deprivation therapy on patients with Gleason 8 cancers reduced risk of death by around 22 percent. Any patients that had Gleason 9 or 10 cancers, however, didn’t share these benefits — in fact, it seems that ADT doesn’t help at all when it comes to survival rates at these levels.
So why is it that Gleason 8 cancers are so responsive to ADT when prostate cancers that are only marginally more aggressive don’t? The scientists involved in the study theorize that it’s due to the type of cancers that get classified as higher than Gleason 8; these tend to be classified as “Gleason pattern 5” diseases, and this research may be evidence that Gleason pattern 5 diseases are either naturally resistant to hormone therapy or have developed a resistance specifically to ADT.
While this certainly seems like bad news for anyone concerned about finding effective treatments for the most aggressive types of prostate cancers out there, there is a silver lining. Identifying places where current treatment methods are lacking provide both the drive and the opportunity to innovate new and hopefully better treatments for any prostate cancer that is classified as Gleason pattern 5. For now, scientists recommend more research into the phenomenon, part of which includes testing whether Gleason 5 pattern diseases respond favorably to increased radiation doses.