Hormonal contraception and chemoprevention of female cancers

Oral contraceptive (OC) use significantly reduces the risk of endometrial a nd ovarian cancer, has only a minimal effect on breast cancer, but may incr ease the risk of cervical cancer. These effects can be readily explained in terms of the effects of OCs on cell proliferation in these tissues. This a nalysis suggests how a hormonal contraceptive based on a GnRH agonist plus low-dose add-back sex steroids could be made that would greatly reduce life time risk of breast and ovarian cancer. Such a hormonal contraceptive is al so likely to significantly reduce the lifetime risk of cervical cancer. It is also likely to reduce the risk of endometrial cancer, although not to th e same extent as OCs.