title: High-dose and low-dose combined oral contraceptives: protection against epithelial ovarian cancer and the length of the protective effect. The WHO Collaborative Study of Neoplasia and Steroid Contraceptives.
abstract: The relations between use of high-dose and low-dose combined oral contraceptives and epithelial ovarian cancer were compared in an international hospital-based case-control study. 393 cases from seven countries were compared with 2561 matched controls. The odds ratio (OR) was somewhat lower for women who used high-dose oestrogen oral contraceptives (OR = 0.68) than for women who used low-dose preparations (OR = 0.81) although the difference could have occurred by chance. After controlling for time since last use, risk was slightly lower for long-term users of high-dose preparations than for long-term users of low-dose pills. Both high-dose and low-dose oral contraceptives protect against ovarian cancer, but the degree of protection may be slightly weaker for the newer, low-dose products.
authors.affiliation: Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
authors.forename: K A
authors.initials: KA
authors.lastname: Rosenblatt
authors.forename: D B
authors.initials: DB
authors.lastname: Thomas
authors.forename: E A
authors.initials: EA
authors.lastname: Noonan
mesh_terms: D016022:Case-Control Studies; D003277:Contraceptives, Oral, Combined / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000517:prevention & control*; D013997:Time Factors
chemical_list: D003277:Contraceptives, Oral, Combined