How Long Should Hormone Therapy Be Given with Radiation?
A large international study combined the results of 13 clinical trials involving more than 10,000 men with localized prostate cancer to determine the best length of androgen deprivation therapy (ADT), or hormone therapy, when it is given with radiation treatment. Most of the men had high- risk or very high-risk prostate cancer and were followed for more than 11 years.
The researchers found that hormone therapy improved outcomes by reducing the risk that prostate cancer would spread, lowering thechance of dying from prostate cancer, and improving overall survival. Most of these benefits occurred during the first 9 to 12 monthsof treatment. Extending hormone therapy beyond one year provided smaller additional benefits.
However, longer treatment also had drawbacks. The longer men remained on hormone therapy, the greater their risk of dying from causes unrelated to prostate cancer. This finding highlights the importance of balancing the benefits of treatment against its long-term side effects.
The ideal duration of hormone therapy depended on the patient’s cancer risk. Men with only one intermediate-risk feature received little benefit from ADT. Those with two or more intermediate-risk features appeared to benefit most from about six monthsof treatment. Men with high-risk or very high-risk prostate cancer benefited from at least 12 months of hormone therapy. However, the study could not determine whether treatment longer than one year provides additional worthwhile benefit.
The researchers concluded that there is no single “best” treatment duration for everyone. Instead, the length of hormone therapy should be individualized based on the patient’s cancer risk, overall health, life expectancy, possible side effects, and personal preferences.
JAMA Oncology. Published online November 20, 2025.
