This is not a new question. We have known for 35 years that leuprorelin acetate (AKA Lupron) is an effective drug for suppressing testosterone (T) down to castrate levels. This new paper, however, looks at that suppression in a bit more detail and in a real-life setting. The data are from 694 patients on ADT in Germany, prescribed Lupron either short term to facilitate radiotherapy or long term because of prostate cancer progression and biochemical failure.
Lupron drove the patients’ T below 0.2 ng/mL within the first month of their first injection. For 92-99% of the men in this study, a three-month depot injection held T below 0.5 ng/mL. But is that good enough? What about those 1-8% of patients whose T snuck up above 0.5 ng/mL? It turns out that those elevated T values were found in 5.3% of all the measurements collected and occurred at the end of the three-month period, when the patients were due for their next injection.
So what does this mean for patients? Although the authors do not comment on that, what it suggests to us is that patients should probably get the T measured when they get their PSA tested. If they are on depot injections of LHRH drugs, like Lupron, and their T is above 0.5 ng/mL, they might consider getting their injections a little more frequently, perhaps a week or two earlier than they might otherwise.
As an aside, it’s interesting to note that the target value of 0.5 ng/mL has been considered the cut off for castrate level T in North America. In Europe, the European Association of Urology suggests a target level of 0.2 ng/mL. But, as the authors note, what needs to be taken into consideration is when the T levels are measured. If it’s one month after a person has started on ADT, we can expect T to be at or below 0.2 ng/mL. On the other hand, if it’s at the end of a multi-month depot injection, we might expect T levels to be closer to the 0.5 mg/mL level.
Bottom line— You can trust the LHRH drugs to do what they’re supposed to do, but there are a few exceptions. If you are on ADT and your T is a bit high, ask you physicians if you can get your depot injections a bit earlier.
To read the study abstract, see: https://pubmed.ncbi.nlm.nih.gov/33631760/
Schmitz-Dräger, B. J., Mühlich, S., Lange, C., Benderska-Söder, N., Bismarck, E., Starlinger, R., Ottillinger, B., & Hakenberg, O. W. (2021). Effectiveness and Distribution of Testosterone Levels within First Year of Androgen Deprivation Therapy in a Real-World Setting: Results from the Non-Interventional German Cohort LEAN Study. Urologia internationalis, 1–10. Advance online publication. https://doi.org/10.1159/000513073