New Trial Examines Adding Hormone Therapy to Radiation Treatment

Radiation therapy is the standard treatment for men whose prostate cancer returns after radical prostatectomy. However, a new trial found that combining salvage radiation therapy with hormone therapy (also known as androgen deprivation therapy, or ADT) significantly delayed disease progression when compared to radiation alone.

The GETUG-AFU 16 trial included 743 patients who were randomly assigned to receive only radiation therapy or radiation plus hormone therapy (with 10.8 mg of goserelin) for 6 months. The goal of the study was to assess progression-free survival in the patients.

Hormone Therapy Delayed Disease Progression

After a median follow-up of 63.1 months, more men in the radiation only group had disease progression than men in the combined treatment group (138 vs. 78). In addition, men in the combined treatment group had a 5-year progression-free survival of 79.6% compared to 62.1% for men who had radiation therapy alone. The 5-year overall survival was 94.8% for radiation therapy vs. 96.2% for combined treatment.

The trial was reported at the 2015 ASCO Annual Meeting in June. It was the first randomized trial comparing these two types of treatment as salvage treatment for biological relapse after radical prostatectomy with undetectable post-op PSA. The researchers noted that a longer follow-up is needed to identify the impact on overall survival.

PHI Test is More Accurate for Obese Patients

A European study compared the accuracy of the PSA and Prostate Health Index (PHI) tests in predicting prostate cancer in obese men. The analysis found that the PHI test was significantly more accurate than current tests in predicting prostate cancer in obese men. With a PHI threshold of 35.7, 32.4% of biopsies for obese men in the study could have been avoided.

The study included 965 patients, 142 of which were obese (BMI ≥30kg/m2). Upon biopsy, prostate cancer was found in 65 obese patients (45.8%).

The study was published in BJU International.

Obesity as Selection Criteria for Active Surveillance

Obesity is associated with an increased risk of high-grade prostate cancer. However, there is little research examining body mass index (BMI) as a predictor of progression in men with low-risk prostate cancer. A recent Italian study aimed to address this.

The study followed 311 patients who were eligible for active surveillance and underwent radical prostatectomy. Obesity was associated with worse prognosis. Specifically, high BMI was significantly associated with tumor upgrading, upstaging and seminal vesicle invasion, i.e., more aggressive or more advanced cancer than was anticipated before surgery. An increase of BMI by 1 unit significantly increased the risk of upgrading, upstaging and seminal vesicle invasion by 21%, 23% and 27% respectively (with multivariate analysis).

The authors concluded that BMI should be included in selection criteria for patients with low-risk prostate cancer who are considering active surveillance.

The study was published online in Urologic Oncology.

Post-Diagnostic Statin Use Does Not Prevent Lethal Prostate Cancer

Observational studies suggest potential preventive benefits of statins on prostate cancer outcomes, but there is little data on the impact of post-diagnostic use. Researchers from the University of California-San Francisco recently examined this association in 3,949 men diagnosed with localized prostate cancer between 1992 and 2008. In this group, 685 men were using statins when they were diagnosed. They followed the men through 2010. There were 242 cases of lethal prostate cancer in the study, defined as metastatic disease or prostate cancer death.

The researchers found that statin use following a diagnosis of localized prostate cancer did not lower the risk of prostate cancer death or metastatic disease. The study concluded, “We observed little evidence that statin usage after diagnosis of localized prostate cancer reduces risk of progression to metastatic disease or prostate cancer specific death.”