A study found that it may be safe to postpone androgen deprivation therapy in men with a PSA-only based relapse after prostate surgery or radiation therapy.
Delaying ADT until the onset of symptoms or appearance of cancer on a scan does not substantially compromise long-term survival, according to the population-based observational study.
“Rising PSA levels trigger a lot of anxiety, and many men want to start treatment as soon as possible,” said lead study author Xabier Garcia-Albeniz, a research associate at Harvard University School of Public Health.
“These findings suggest that there may be no need to rush to ADT.”
“If our results are confirmed in randomized trials, patients could feel more comfortable waiting until they develop symptoms or signs of cancer that are seen on a scan, before initiating ADT,” said Garcia-Albeniz.
The study will be presented June 1 at the American Society of Clinical Oncology annual meeting in Chicago.
The study provided novel data on patients with so-called “PSA relapse,” where PSA levels are increased but patients have no symptoms, and there is no evidence of a tumor on a CT or bone scan. There are no standard guidelines for timing of ADT initiation in such patients.
The study analyzed national prospective registry data (CaPSURE: Cancer of the Prostate Strategic Urologic Research Endeavor, based at the University of California, San Francisco) on over 14,000 patients, 2,012 of whom had a PSA relapse after radical prostatectomy or radiation therapy with curative intention. Patients were assigned to the “immediate” strategy if they received ADT within three months of PSA relapse. They were assigned to the “deferred” strategy if they started ADT at least two years after the PSA relapse, or when they presented with metastasis, symptoms, or a short PSA doubling time.
The median time from primary treatment to PSA relapse was 27 months. After a relapse, patients were followed for a median period of 41 months. The estimated five-year overall survival was similar between the two ADT timing strategies: 87.2 percent for deferred ADT vs. 85.1 percent for immediate ADT, suggesting that there was little or no survival benefit of immediate ADT initiation compared with deferred initiation.
In practice, deferred initiation could help delay ADT by two or more years for some men, according to the authors, offering men substantially better quality of life by avoiding common and often debilitating side effects.
Targeted Biopsy More Effective At Selecting Men For Active Surveillance, Study Says
Researchers found that selection of men for active surveillance for prostate cancer should be based not on conventional biopsy, but with imaging-guided targeted biopsy.
Conventional “blind” biopsy failed to reveal the true extent of presumed low-risk prostate cancers, and that when targeted biopsy was used, more than a third of these men had more aggressive cancers than they thought, according to researchers at UCLA.
Their aggressive cancers were not detected by conventional blind biopsy using ultrasound alone, and the men were referred to UCLA’s active surveillance program thinking they were at no immediate risk. The new biopsy method is now a routine part of the UCLA active surveillance program.
The study was published in Urology. The targeted biopsy method is performed by combining MRI with real-time ultrasound. This study is the first to show the value of using it early in the selection process for men interested in active surveillance.
“These findings are important as active surveillance is a growing trend in this country,” said study senior author Leonard Marks, a professor of urology and director of the UCLA Active Surveillance Program. “It’s touted as the best course for many men thought to have slow-growing cancers. But we show here that many men thought to be candidates for active surveillance based on conventional biopsies really are not good candidates.”
Researchers identified 113 men enrolled in the UCLA active surveillance program who met the criteria for having low-risk cancers based on conventional biopsies. Study volunteers underwent an MRI to visualize the prostate and any lesions. That information was then combined with three-dimensional ultrasound, allowing the urologist to visualize and target lesions during the biopsy.
Of the 113 volunteers enrolled in the study, 41 men, or 36 percent, were found to have more aggressive cancer than initially suspected.
