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
Rosenblatt, K.A.; Thomas, D.B.; Noonan, E.A.
European Journal of Cancer 28a (11): 1872-1876
1992
ISSN/ISBN: 0959-8049 PMID: 1389530 DOI: 10.1016/0959-8049(92)90026-xDocument Number: 361653
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.