Oral Contraceptive Use and Risk of Breast, Cervical, Colorectal, and Endometrial Cancers: A Systematic Review
A partir d'une revue systématique de la littérature, cette étude fait le point sur l'association entre l'utilisation d'une contraception orale et le risque de cancer du sein, du col de l'utérus, du côlon-rectum et de l'endomètre
Oral contraceptives (OC) may influence the risk of certain cancers. As part of the AHRQ Evidence Report, Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer, we conducted a systematic review to estimate associations between OC use and breast, cervical, colorectal, and endometrial cancer incidence. We searched PubMed®, Embase®, and Cochrane Database of Systematic Reviews. Study inclusion criteria were women taking OCs for contraception or ovarian cancer prevention; includes comparison group with no OC use; study reports quantitative associations between OC exposure and relevant cancers; controlled study or pooled patient-level meta-analyses; sample size for nonrandomized studies >100; peer-reviewed, English-language; published from January 1, 2000 forward. Random-effects meta-analyses were performed by estimating pooled odds ratios with 95% confidence intervals. We included 44 breast, 12 cervical, 11 colorectal, and 9 endometrial cancers studies. Breast cancer incidence was slightly but significantly increased in users (OR=1.08, CI 1.00-1.17); results show a higher risk associated with more recent use of OCs. Risk of cervical cancer was increased with duration of OC use in women with human papillomavirus infection; heterogeneity prevented meta-analysis. Colorectal cancer (OR=0.86, CI 0.79-0.95) and endometrial cancer incidences (OR=0.57, CI 0.43-0.77) were significantly reduced by OC use. Compared with never use, ever use of OCs is significantly associated with decreases in colorectal and endometrial cancers and increases in breast cancers. Although elevated breast cancer risk was small, relatively high incidence of breast cancers means that OCs may contribute to a substantial number of cases.