Use of oral contraceptives, intrauterine devices and tubal sterilization and cancer risk in a large prospective study, from 1996 to 2006

Abstract

The association of contraceptive methods, including oral contraceptives (OC), intrauterine devices (IUD) and tubal sterilization (TS), with overall and site-specific cancer were prospectively investigated in a cohort of 66,661 Chinese women in Shanghai, 76.7% of whom used contraception. During a median follow-up time of 7.5 years, 2,250 women were diagnosed with cancer. Everuse of any contraceptive method was not associated with overall cancer risk [adjusted hazard ratio (HR adj ) 5 1.02, 95% CI, 0.92-1.12]. Use of any contraceptive method was associated with increased risk of rectal cancer (HR adj 5 1.68, 95% CI, 1.08-2.62) and reduced risk of thyroid cancer (HR adj 5 0.63, 95% CI, 0.38-1.04). Risk of gallbladder cancer increased with ever use of OC (HR adj 5 2.38, 95% CI, 1.26-4.49). IUD use was associated with a possible reduced risk of thyroid cancer (HR adj 5 0.64, 95% CI, 0.38-1.07). Longer duration of IUD use decreased risk for breast, thyroid and lung cancers. Ever having a TS was associated with increased uterine body cancer (HR adj 5 2.50, 95% CI, 1.47-4.25) and decreased risk of stomach cancer (HR adj 5 0.59, 95% CI, 0.39-0.91). We did not find any contraceptive method to be related to the risk of ovarian cancer but the analyses were based on few events. Although chance findings are a likely explanation for some of the associations found in our study, these findings suggest that various contraceptive methods or reproductive patterns may play a role in the etiology of cancer.

Tubal Ligation and Incidence of 26 Site-Specific Cancers in the Million Women Study

“…Reports of the relationship between tubal ligation and breast cancer risk have been varied, including suggestions of either a reduced Calle et al, 2001) or increased risk (Irwin et al, 1988), although the majority of studies reported no significant association Eliassen et al, 2006;Iversen et al, 2007;Dorjgochoo et al, 2009;Press et al, 2011;Gaudet et al, 2013;Nichols et al, 2013), consistent with our findings.…”

“…The strongest association was with a history of cervical intraepithelial neoplasia grade 3 (RR ¼ 4.03, 95% CI: 2.59-6.28), reflecting the importance of high-risk strains of human papilloma virus as causative agents of both cervical (Walboomers et al, 1999) example, as tubal ligation is usually performed for permanent contraception, it is likely to be more common among women who are sexually active, and who thus may be more likely to be exposed to sexually-transmitted infections, such as human papilloma virus, and the consequent increased risk of anal cancer. There have been reports on possible relationships between tubal ligation and other cancers, including possible reductions in risk of colorectal (Cape and Kreiger, 1999;Rosenblatt et al, 2004) and stomach cancer (Dorjgochoo et al, 2009), and increased risks of thyroid cancer (Braganza et al, 2014) and lymphatic and haematopoietic malignancies (Kjaer et al, 2004). We did not replicate any of these findings.…”

Estrogen-dependent gallbladder carcinogenesis in LXRβ −/− female mice

“…Female sex (19), use of contraceptive pills (46), and oral hormonal replacement therapy (25) are associated with high risk of gallbladder cancer, indicating a strong role for estrogens in the carcinogenesis process of this organ. Only female LXRβ −/− animals demonstrate preneoplastic lesions and the elimination of estrogens with ovariectomy prevents the formation of these lesions (Fig.…”

Oral Contraceptive Use and Risk of Breast, Cervical, Colorectal, and Endometrial Cancers: A Systematic Review

“…Eleven studies (4 good, 6 fair, 1 poor quality) evaluated the association between oral contraceptive use and colorectal cancer incidence (63,65,66,68,(88)(89)(90)(91)(92)(93)(94)(95). Of these, 3 were case-control studies, 7 were cohort studies, and 1 was a pooled analysis.…”