Is there a relationship between one’s testosterone levels pretreatment and overall survival for men who get brachytherapy and ADT combined?

ADT is frequently combined with brachytherapy to treat prostate cancer. Although this can decrease the risk of dying from the cancer, the side effects of ADT, such as metabolic syndrome, can increase the risk of dying from other causes, such as diabetes and cardiovascular disease. So is there any way to predict who will benefit overall from adding ADT to brachytherapy and who will not?

In a recent study, researchers examined data from 1,916 men who completed brachytherapy treatment, 26% of whom also received ADT. The researchers collected serum testosterone levels from all the men prior to the start of their treatment, and looked at mortality data after 10 years. Their results are summarized below.

- The risk of prostate cancer-specific death, even in patients with high-risk prostate cancer, was very low, at 0.8% after 10 years.

- The overall mortality after 10 years was 22%.

- The strongest predictors of overall mortality were age, tobacco use, diabetes, cardiovascular disease, and % positive biopsy samples.

- Increased risk of overall mortality was found only in men who had lower than normal testosterone levels prior to starting brachytherapy and ADT, when compared with men who received brachytherapy without ADT.

- In men with normal or higher pre-treatment testosterone, ADT use was not associated with increased risk of overall mortality.

The researchers note that low testosterone is frequently associated with greater risk of cardiovascular disease and myocardial infarctions (heart attacks). Higher rates of fatal myocardial infarctions may have contributed to the association of low pre-treatment testosterone and subsequent elevated overall mortality in the men who received ADT plus brachytherapy.

These findings suggest that pretreatment measurements of testosterone levels may help clinicians identify men who might be better off not using ADT, if they are going for brachytherapy. The study highlights the importance of remaining mindful of cardiovascular health when undergoing ADT.

For more information on the study, please see:

Taira, A. V., Merrick, G. S., Galbreath, R. W., Butler, W. M., & Adamovich, E. (2018). Impact of androgen deprivation therapy on overall mortality in prostate brachytherapy patients with low pretreatment testosterone levels. American Journal of Clinical Oncology, 41(7), 667-673. doi: 10.1097/COC.0000000000000340