E4 is a steroid that may become a treatment for advanced prostate cancer, both alone and fin combination with hormone therapy. Ellen Dutman, MSc, a clinical researcher, studied E4 as a treatment to lower testosterone.

“An important advantage of E4 is expected to be the avoidance of the hypoestrogenic side effects that occur with other types of testosterone-suppressing hormone therapy, including hot flushes and sweating, arthralgia, mood, sleep and cognition disturbances, and bone loss and fractures,” said Ms Dutman.

In Ms. Dutman’s study, E4 doses were well tolerated, with no change in body weight or safety parameters, but libido decreased and nipple tenderness was reported.

“E4 treatment may not be as expensive as recently developed new prostate cancer therapies,” said Ms Dutman. “We expect that in the future, patients with advanced prostate cancer will have the opportunity to choose to be treated with E4, especially in combination with their current therapy.”


  1. Dutman AE, Zimmerman Y, Bennink HJTC. The effects of the human fetal estrogen estetrol (E4) in healthy men to estimate its potential use for the treatment of prostate cancer. Poster presented at: ENDO 2017, the annual scientific meeting of the Endocrine Society; April 1-4, 2017; Orlando, FL. Abstract SAT 171.