LHRH-RECEPTORS AND LHRH-AGONIST TREATMENT IN OVARIAN-CANCER - AN OVERVIEW

Considerable evidence exists that ovarian cancer might be gonadotrophin-dependent. Receptors for LH and FSH have been discovered in these tumors. Proliferation of ovarian cancer cells in vitro could be stimulated by gonadotrophins. Withdrawal of LH and FSH in animal models of ovarian cancer inhibited growth of these tumors. Phase-II clinical studies have shown that suppression of endogenous gonadotrophins by LHRH-agonists can be beneficial in women with advanced ovarian cancer. Respective controlled clinical trials are performed at present. Also direct effects of LHRH analogues on ovarian tumors have been reported. An LHRH like protein was found in human ovarian tissue. We discovered a specific LHRH binding site (mol. wt 63.2 kDa) in ovarian cancer tissue which is very similar to other human extrapituitary LHRH binding sites, of the low-affinity, high-capacity type, e.g. in breast cancer and the placenta. In the latter tissues, LHRH or a related substance has been proposed as an autocrine regulator of cellular function. If this was also the case in ovarian cancer, direct effects of LHRH analogs on the tumor cells could be used as additional therapeutical points of attack.