Over the past 2 decades, the field of urology has made dramatic progress in understanding the etiology and pathophysiology of BPH/lower urinary tract symptoms.
"The field has entered a period of reflection as we consider the vast amount of information and data that have accumulated and try to determine how we can make further improvements in clinical practice to maximize the benefits for patients," said Steven A. Kaplan, MD, professor of urology and chief of the Institute for Bladder and Prostate Health at Weill Cornell Medical College, New York.
One area that has attracted considerable attention relates to mounting evidence of associations between BPH/LUTS and other chronic medical conditions, including diabetes and obesity. Studies presented at the upcoming AUA annual meeting in San Francisco represent ongoing efforts to characterize and define the nature of the associations, including the directionality of the associations.
Studies of botulinum toxin will include an update of an ongoing National Institutes of Health-sponsored study. One analysis examines the association between baseline characteristics, especially PSA levels, and outcomes with botulinum toxin therapy.
"It's not clear how Botox works, but we know it doesn't work by shrinking the prostate," Dr. Kaplan said. "The prostate size or volume does not change. We used to think that Botox worked by decreasing prostate volume, but that's clearly not the case."
Wider use of combination therapy?
Other investigations will focus on refining indications for use of combination medical therapy. Combination therapy appears to work best in patients with larger prostates, and data will be presented to support that observation. However, the landmark Medical Therapy of Prostatic Symptoms (MTOPS) study showed that half of patients with BPH/LUTS have prostates that are <30 grams.
"It will be interesting to see how many men with smaller prostates, if any, might benefit from combination therapy," said Dr. Kaplan. "We know that combination therapy is effective in relieving symptoms associated with large prostates, but we have no data from the CombAT [Combination of Avodart and Tamsulosin] study to indicate how applicable combination treatment might be in other men."
Other AUA reports will focus on the long-term safety and efficacy of 5-alpha-reductase inhibitors for treatment of BPH/LUTS. Urologists and patients should be reassured by the clinical track record the drug class has compiled.
More data on PSA-activated protoxin
Other research from the AUA meeting to look for includes ongoing evaluations of a bioengineered PSA-activated protoxin (PRX302) that represents a new approach to treatment of BPH/LUTS. The agent is injected into the prostate, activated by exposure to PSA, and then creates small holes in the organ, effecting shrinkage.
New delivery systems for treatments, including ablative therapies, also are being evaluated. More efficient or accurate targeting of therapy might lead to more effective treatment. Preliminary, but promising, data on use of nanoparticles to deliver ablative therapy will be presented at the meeting.
Several new lasers have been developed in an effort to improve on currently available technology for treatment of BPH/LUTS. Whether the new devices translate into better treatment remains to be seen.
"I'm not sure that the different energy sources or delivery systems will make a difference," Dr. Kaplan said. "The data presented thus far have come primarily from small, single-center studies. Personally, I think operators become comfortable with one device or another and use that device in most cases or exclusively, and there's nothing wrong with that."
Given the new knowledge and clinical tools for BPH/LUTS, the challenge in urology is to determine where each type of therapy works best as a component of the entire spectrum of therapy, he added. Studies reported at the upcoming AUA meeting will provide an update as to how far the field has come in meeting that challenge.