Late-stage prostate cancer: Prolonging survival with immediate hormone therapy

This study compared immediate and delayed androgen deprivation therapy (ADT) for men with relapsed or non-curable prostate cancer. Authors reported improved survival and disease progression with immediate ADT.

ADT is a type of hormone therapy used to treat prostate cancer. It targets the production of male hormones (such as testosterone) and reduces their effect on cancer cell growth. Reducing androgen levels can dramatically improve survival. ADT is often the first-line treatment for advanced prostate cancer, including cancer that has spread (metastatic). It also offers a survival benefit to patients with relapsed disease or those not suitable for curative therapy (such as surgery or radiation). Recurrent disease is usually defined by rising PSA levels (prostate specific antigen; a protein elevated in the blood in prostate cancer) after initial treatment.

The optimal timing of initiating ADT after PSA relapse is still being debated. Since ADT is associated with a number of side effects, some men may benefit from delayed treatment. However, immediate treatment may offer better cancer control.

The aim of this study was to compare immediate and delayed ADT in men with relapsed or non-curable prostate cancer.

This study included 293 men with recurrent advanced prostate cancer not suitable for curative therapy. Most men (89.1%) had PSA relapse. Men were randomly assigned to either undergo immediate ADT (started within 8 weeks) or delayed ADT (started after at least 2 years). All patients could take breaks between treatments (intermittent ADT) with a minimum of 9 months of ADT at a time. 64 to 71% of physicians prescribed intermittent ADT to patients. Treatment outcomes were followed for an average of 5 years.

11% of men undergoing immediate ADT died during the study follow-up. In contrast, 20% of men undergoing delayed ADT died during the same period. The 5-year overall survival rate (proportion who have not died from any cause since treatment) was 91.2% with immediate ADT and 86.4% with delayed ADT. Overall, men undergoing immediate ADT were 55% more likely to survive the study period compared to delayed ADT. This was not affected by choice of intermittent ADT, the rate at which PSA was rising, and the type of treatment center.

The time until local or distant disease progression was significantly longer with immediate ADT. In the immediate ADT group, 13% showed local progression and 19% showed distant progression (metastases) during the study period. In the delayed ADT group, 20% showed local progression and 20% showed distant progression. Overall, immediate ADT reduced the risk of local progression by 49%. The risk of becoming resistant to treatment was also reduced by 24% with immediate ADT.

The most frequent side effects included hot flushes, erectile dysfunction, fatigue, and male breast enlargement. 10% of men reported serious side effects. The most common serious side effects were related to the heart and blood vessels (reported in 9% of men in immediate and 6% in delayed ADT). No significant differences in side effects or quality of life were noted between the two ADT groups. 

Authors concluded that survival can be prolonged with immediate ADT in men with relapsed or non-curable prostate cancer.