Tumor flare occurs
during the use of the LHRH agonist and GnRH agonist.
The agonist occupies the receptors of the pituitary
gland, and for the first seven to ten days after prostate
cancer hormone therapy begins, the levels of testosterone
spike. After this period of tumor flare, the level of
testosterone drops to castrate levels which slows or
stops the growth and spread of prostate cancer. Tumor
flare is also known as hormone flare.