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.
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.
Rosenblatt
K A
KA
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Thomas
D B
DB
Noonan
E A
EA
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
D003277:Contraceptives, Oral, Combined