One of the many constantly recurring topics that we discuss is over the efficacy of intermittent hormone deprivation therapy (IAD) as opposed to continuous hormone deprivation therapy (CAD). Which therapy is better has been debated for at least ten years. The debate still rages over the question of efficacy, or survival as well as the quality of life (QOL).

Often, the debate does not consider whether one therapy might be superior depending upon the individual man’s disease state. A recent study evaluated the efficacy of these two treatment schedules in men with non-metastatic relapsing, locally advanced prostate cancer.

The study was conducted for 42-months and consisted of a phase 3b open-label randomized study using 933 men from 20 European countries.

All the subject men had a 6-month induction with leuprorelin acetate (Eligard) 22.5mg 3-month depot. They were then randomized to CAD or IAD with leuprorelin for 36 months.

The primary end point of the research was time to prostate-specific antigen (PSA) progression while receiving the Eligard. Three consecutive increasing PSA values greater than or equal to 4 ng/ml in the time period of 2 or more weeks apart were considered failure. Secondary end points included PSA progression-free survival (PFS), overall survival (OS), testosterone levels, performance status, and QoL.

Of the 933 men in the induction phase; 701 were eventually randomized.

They found that the IAD and CAD arms demonstrated similar efficacy, tolerability, and QoL in men with non-metastatic prostate cancer. In this study the principal benefit of IAD compared with CAD was only the potential cost reduction of IAD.