or search on
|Title:||Injectable and Oral Contraceptive Use and Cancers of the Breast, Cervix, Ovary, and Endometrium in Black South African Women: Case–Control Study|
|Authors:||Urban M; Banks E; Egger S; Canfell K; O’Connell DL; Beral V; Sitas F|
|Categories:||Cancer Type - Breast Cancer|
Cancer Type - Cervical Cancer
Cancer Type - Endometrial Cancer
Cancer Type - Ovarian Cancer
Etiology - Exogenous Factors in the Origin and Cause of Cancer
|Journal Title:||PLOS Medicine|
|Abstract:||Abstract Background Oral contraceptives are known to influence the risk of cancers of the female reproductive system. Evidence regarding the relationship between injectable contraceptives and these cancers is limited, especially in black South Africans, among whom injectable contraceptives are used more commonly than oral contraceptives. Methods and Findings We analysed data from a South African hospital-based case–control study of black females aged 18–79 y, comparing self-reported contraceptive use in patients with breast (n = 1,664), cervical (n = 2,182), ovarian (n = 182), and endometrial (n = 182) cancer, with self-reported contraceptive use in 1,492 control patients diagnosed with cancers with no known relationship to hormonal contraceptive use. We adjusted for potential confounding factors, including age, calendar year of diagnosis, education, smoking, alcohol, parity/age at first birth, and number of sexual partners. Among controls, 26% had used injectable and 20% had used oral contraceptives. For current and more recent users versus never users of oral or injectable contraceptives, the odds ratios (ORs) for breast cancer were significantly increased in users of oral and/or injectable contraceptives (OR 1.66, 95% CI 1.28–2.16, p<0.001) and separately among those exclusively using oral (1.57, 1.03–2.40, p = 0.04) and exclusively using injectable (OR 1.83, 1.31–2.55, p<0.001) contraceptives; corresponding ORs for cervical cancer were 1.38 (1.08–1.77, p = 0.01), 1.01 (0.66–1.56, p = 0.96), and 1.58 (1.16–2.15, p = 0.004). There was no significant increase in breast or cervical cancer risk among women ceasing hormonal contraceptive use ≥10 y previously (p = 0.3 and p = 0.9, respectively). For durations of use ≥5 y versus never use, the ORs of ovarian cancer were 0.60 (0.36–0.99, p = 0.04) for oral and/or injectable contraceptive use and 0.07 (0.01–0.49, p = 0.008) for injectable use exclusively; corresponding ORs for endometrial cancer were 0.44 (0.22–0.86, p = 0.02) and 0.36 (0.11–1.26, p = 0.1). Conclusions In this study, use of oral and of injectable hormonal contraceptives was associated with a transiently increased risk of breast and cervical cancer and, for long durations of use, with a reduced risk of ovarian and endometrial cancer. The observed effects of injectable and of oral contraceptives on cancer risk in this study did not appear to differ substantially.|
|Division:||Cancer Research Division|
|Funding Body:||The NHLS/MRC Cancer Epidemiology Research Group at the National Health Laboratory Service is currently funded by the South African Medical Research Council and the (South African) National Health Laboratory Service; previous funding was received from the University of the Witwatersrand, CANSA (Cancer Association of South Africa), and Cancer Research UK. The Cancer Epidemiology Research Unit at The Cancer Council NSW is funded in the main by The Cancer Council New South Wales. The Cancer Research UK Epidemiology Unit is supported by Cancer Research UK. EB and KC are supported by the Australian National Health and Medical Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.|
|Appears in Collections:||Research Articles|
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.