Similar treatment outcomes following intermittent and continuous hormone therapy

This study compared intermittent and continuous androgen deprivation therapy (ADT) in treating locally advanced prostate cancer. Researchers reported that both intermittent and continuous ADT were equally as effective and well-tolerated.

ADT is a type of hormone therapy that blocks male hormones (such as testosterone) active in prostate cancer. ADT has improved survival among many patients. It is currently the standard-of-care for advanced prostate cancer.

Continuous ADT, however, is associated with a number of side effects. These include a decreased sex drive, impotence, a gain in body fat, increased insulin resistance, and brittle bones. An alternative approach is to apply ADT intermittently, with breaks between treatments. The aim of intermittent ADT is to lessen the intensity of potential side effects. However, the relative benefits of intermittent versus continuous ADT remain unclear.

This study compared intermittent ADT (I-ADT) and continuous ADT (C-ADT) in 701 men with locally advanced prostate cancer. After a 6-months course of ADT, men were randomly assigned to either take a break (I-ADT) or continue treatment (C-ADT). Men undergoing I-ADT restarted treatment every 3 months if blood markers indicated prostate growth. Both I-ADT and C-ADT were stopped after 3 years.

36% of men receiving I-ADT did not need to restart treatment after the first year. 22% of men did not need further ADT after the second year. After 3 years, 16% of men undergoing I-ADT did not need to restart treatment.

There were no differences in treatment effectivity between I-ADT and C-ADT. Overall survival, disease progression, as well as quality of life were all similarly improved. 5-year overall survival (time from treatment until death from any cause) was 85% for C-ADT and 81.8% for I-ADT. Disease progression after 3 years was observed in 10.6% of men undergoing C-ADT and in 10.1% of men undergoing I-ADT.

Overall, 25.8% of men experienced one or more serious side effect associated with ADT. Hot flushes, high blood pressure, and constipation were among the most commonly reported. A similar number of side effects was observed for I-ADT and C-ADT.

The researchers concluded that there are no differences in safety and effectiveness between intermittent and continuous ADT in treating locally advanced prostate cancer.