A national study, published in the Journal of Clinical Oncology and led by Dr. Daniel Krauss, a radiation oncologist with Corewell Health in southeast Michigan, is giving patients with intermediate-risk prostate cancer a clearer picture of what to expect when it comes to treatments involving hormonal therapy and radiation.
While the primary finding of the research indicated that the addition of hormonal therapy to radiation treatment did not improve overall survival, the added therapy did improve other clinical outcomes such as decreasing the chances of patients still exhibiting elevated prostate-specific antigen (PSA) levels, or having cancer recurrence by 48%, as well as decreasing the risk of the cancer spreading by 75% or death due to prostate cancer by 90%.
The addition of the hormonal therapy during the clinical trial also gave physicians a better look at what individuals could expect when it came to the side effects of the therapy. Two temporary side effects included a significant decrease in a patient’s hormone levels and some sexual disfunction, but after one year, those issues seemed to subside. Additionally, regular bowel or urinary functions stayed the same.
Dr. Krauss shares more on what individuals need to know about the impact of this study on prostate cancer treatment.
WHAT IS HORMONAL THERAPY, AND HOW DOES IT WORK?
Hormonal therapy for prostate cancer typically refers to drugs that suppress the body’s production of testosterone. A low testosterone environment has been shown to improve the effectiveness of radiation therapy in men with certain types of non-metastatic prostate cancer.
IS HORMONAL THERAPY WITH RADIATION CURRENTLY PRESCRIBED FOR OTHER LOWER- AND HIGHER-RISK PROSTATE CANCERS?
Hormonal therapy is routinely prescribed and has been shown in the past to improve survival in men with aggressive, or high-risk forms of prostate cancer. Other studies have indicated improved survival in men with intermediate-risk prostate cancer as well, but in those cases, the radiation treatment was less aggressive than what was used in this current study. In cases of low-risk prostate cancer, hormonal therapy is not needed.
WHAT ELSE ABOUT THIS STUDY IS IMPORTANT TO NOTE FOR PHYSICIANS AND PATIENTS ALIKE?
This is the first prospective study defining the survival and overall cancer control benefits of hormonal therapy exclusively in the intermediate-risk prostate cancer population, which is the most common group of men receiving radiotherapy for prostate cancer. Study participants were given radiation therapy techniques directly comparable to those used in current clinical practice.
This study had an accompanying patient-reported, prospective, quality-of-life analysis, which gives physicians the ability to study the benefits of hormonal therapy with a quantifiable description of the impact it would be expected to have on their patient’s daily activities.
CAN YOU EXPLAIN MORE ABOUT THE SIDE EFFECTS PATIENTS IN THE STUDY EXPERIENCED?
The side effects observed in the study were largely those that would be expected with the combination of radiotherapy and hormonal therapy:
Radiotherapy: irritative symptoms related to rectal and bladder function as well as mild fatigue
Hormonal therapy: fatigue, hot flashes, sweats, weight gain, sexual side effects (ED, loss of libido)
As mentioned above and per patient reported outcomes, most of the increased toxicity for patients getting hormonal therapy was resolved by one year following the start of treatment, at which point patient well-being metrics were not significantly different between the study’s two randomization arms.
WHAT IS THE MAIN TAKEAWAY OF THIS STUDY THAT YOU WANT PEOPLE TO KNOW?
While hormonal therapy together with high-dose radiotherapy did not improve overall survival compared to patients treated with high-dose radiotherapy alone, it did improve long-term cancer control rates including a reduction in the odds of the cancer spreading outside the prostate. These benefits can now be explained to patients with a clearer, more detailed expectation of what to expect in terms of both cancer outcomes and side effects than could be done previously.
HOW WILL THIS SERVE AS A FOUNDATIONAL STUDY FOR FUTURE RESEARCH ON PROSTATE CANCER TREATMENT?
Now that we know there are patients with intermediate-risk prostate cancer who benefit from the addition of hormonal therapy to high-dose radiotherapy, the challenge will be to better select patients MOST likely to benefit from the treatment. Incorporation of newer technologies in imaging (e.g. MRI, PET, etc.) and genomic classification are being actively studied and are expected to dramatically decrease the likelihood of giving hormonal therapy to patients who wouldn’t benefit from the treatment.