This ninety-first volume of IARC Monographs contains evaluations of the carcinogenic hazard to humans of combined estrogen-progestogen contraceptives and combined estrogen-protestogen menopausal therapy. The hormonal drugs reviewed in this volume involve co-administration of an estrogen and a progestogen. Studies that did not provide information on the use of combined estrogen-progestogen agents are not reviewed. It should also be noted that this volume reviews only studies that are publicly available and therefore does not include pharmaceutical test results that are not in the public domain.