While the below is inconclusive having testosterone levels ≤ 0.7 nmol/L (about
21 ng/dl) during the first year of ADT seems prudent to me.
Although the primary purpose of the Canadian-led pr.7 trial in men with nonmetastatic disease was for continuous vs intermittent ADT some sub data was analyzed.
“The data from [this] study represent some of the strongest evidence to date that failure to achieve deep testosterone suppression after first-line ADT may herald poor outcomes in men with hormone-sensitive nonmetastatic prostate cancer,” wrote Daniel L. Suzman, MD, and Emmanuel S. Antonarakis, MD, of the Prostate Cancer Research Program at Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins in Baltimore, in their accompanying editorial.
Based on the current analysis of the PR-7 trial, Klotz and colleagues recommend that men starting ADT should have their testosterone and prostate-specific antigen (PSA) levels checked regularly during the first year of therapy. They also recommend that if testosterone levels ≤ 0.7 nmol/L are not achieved during ADT, then the type of hormone therapy be changed.
But, the editorial authors believe that caution is warranted in interpreting these post hoc results because “the primary analysis of the PR-7 study showed that intermittent hormone therapy was non-inferior to continuous therapy with respect to overall survival.” Therefore, the importance of the further manipulation of testosterone levels in prostate cancer patients after ADT is still unclear. They also point to an ongoing trial, the SWOG-S1216 trial, which is currently evaluating the role of deeper testosterone suppression. “Until these or similar results are available, we should not recommend deeper androgen suppression in the first-line setting for men with (metastatic or nonmetastatic) hormone-sensitive prostate cancer,” concluded Suzman and Antonarawww.cancernetwork.com/prostate-cancer/testosterone-levels-during-adt-may-predict-prostate-cancer-outcomes