Assessing the Duration of Intermittent ADT

ADT works by blocking male sex hormones called androgens, as lowering the levels of these hormones can slow the cancer’s growth.

Increasingly, men with prostate cancer have “intermittent” androgen deprivation therapy (ADT), rather than continuous hormone therapy. With intermittent ADT, the patient goes on ADT for a set amount of time or until his PSA drops, followed by an off period. The patient starts the ADT again either when his PSA begins to rise or after a set amount of time. Research is continuing to assess the efficacy of intermittent therapy at controlling the spread of the disease compared to continuous hormone therapy.

The benefit of having intermittent ADT with an “off” period is that the treatment has some unpleasant side effects, such as weight gain, especially belly fat, as well as fatigue, loss of muscle mass, and increased risks of cardiovascular problems with continuous treatment. Some research has also linked ADT use with increased risks of Alzheimer’s and dementia, although these findings have not been consistent. Intermittent therapy also reduces the cost of treatment.

The recent CONSORT trial randomized 90 prostate cancer patients to receive ADT for either four or ten months to see if the longer initial treatment period led to men having a longer length of time between the next treatment. The men in the study had already undergone local therapy for prostate cancer and had subsequent rising PSAs, indicating recurrent cancer.

Ultimately, the study found no difference in the duration of off treatment times between men who had initial ADT for four or ten weeks. The two groups of men also had similar rates of testosterone recovery. However, men in the four-month treatment group saw less of a negative impact on their quality of life than men who were on ADT for ten months.