Brachytherapy: positive long-term survival outcomes

This study examines the 15-year cancer-specific and overall survival in men treated with prostate brachytherapy.

Brachytherapy is a form of radiotherapy used for the treatment of some cancers including prostate cancer. It involves a radiation source being implanted inside the body next to the cancer. Brachytherapy can be used alone or combined with other therapies, such as hormone therapy, external beam radiotherapy (uses a high-energy x-ray machine to direct radiation to the tumor from outside the body) or chemotherapy.

Previous studies have shown that low-risk prostate cancer patients are highly likely to experience cancer-specific survival (surviving cancer in the absence of other causes of death). For higher-risk patients very little is known about the long-term outcome. As well as this, little is known about the impact of long-term hormone therapy in high-risk patients.

A total of 1,669 men with prostate cancer that had not spread beyond to the seminal vesicles (glands positioned below the bladder; stage T1 – T3) were included in the study. Patients were followed for an average of 10 years. Patients were grouped based on risk and received the following treatments: brachytherapy implant alone (low risk), implant plus hormone therapy or external beam irradiation (intermediate risk), or implant plus hormone therapy plus external beam radiotherapy (high risk). Overall hormone therapy was administered to 898 men (53.8%) for an average of 6 months.

The 15-year cancer-specific survival rate was 94.1%. Cancer-specific survival was high in all risk groups: 96.3% for low-risk, 97.5% for intermediate-risk, and 85.2% for high-risk. The 15-year overall survival rate was 57%, indicating that that the majority of deaths were not due to the cancer. Hormone therapy increased the risk of mortality by 4%, but risk was not increased when hormone therapy was limited to 6 months or less. The presence of diabetes, atrial fibrillation (abnormal heart rhythm), emphysema (air sacs of the lungs are damaged) and smoker status all significantly increased the risk of mortality.

The authors concluded that prostate brachytherapy yields favorable 15-year cancer-specific survival.