OS versus Testosterone Nadir - 5

[janebob99]

This plot shows the Overall Survival Probability after RT and ADT, for Advance Prostate Cancer men, comparing two different ranges of testosterone nadir (< 10 ng/dL, and 10-20 ng/dL) after 11 years.

The best outcomes are significantly associated with a lower testosterone nadir ( < 10 ng/dL).

At 11 years, the OS probability = 95% for T-nadir <10 ng/dL, compared to only 70% for T-nadir = 10-20 ng/dL. That's a significant (and important) difference !

This may be well-known to many of you, but it was new to me. (Ref: 2024)

The prior definition of castration being < 50 ng/dL probably needs to redefined to < 20 or < 10 ng/dL. (I read that the level of 50 ng/dL may be an artifact representing the lowest limit that testosterone could be accurately measured many years ago. That makes sense to me).

Ref: (2024) bjui-journals.onlinelibrary...

[maley2711]

True that lower T nadir also correlated with lower PSA nadir......which is more often the number that is folowed of course.

[janebob99 in reply to maley2711]

You're right!

Here's a plot that I made today showing a linear drop in PSA as you decrease testosterone (using estrogen patches...but the same relationship should hold for Lupron ADT, since estrogen and Lupron work the same way on reducing testosterone.)

Bob

PSA vs Testosterone

[dhccpa]

Encouraging!