He requested that every time they had a breast surgery that they take a blood test and save it so that he could test the progesterone level at the time of surgery. He tested testosterone, progesterone and estrogen. He found that progesterone level at the time of surgery was correlated with better survival. This was written up in the British Journal of Cancer in 1996. There is no treatment that provides that degree of benefits.
Progesterone is the treatment.
He calls estrogen the angel of life, the angel of death. It is necessary at the beginning to create a successful pregnancy, and if you have estrogen dominance later in your life it is the angel of death. When the body tries to metabolize estradiol and estrone it is possible to end up in this pathway which ends up in cancer. This is real human estrogen, and the body is trying to get rid of it. If the body does it correctly it methylates it, and it is safely excreted.