What are the cancer risks associated with using combined oral contraceptives (COCs) and what alternatives are available?

From the Guidelines

Combined oral contraceptives (COCs) carry a small increased risk of certain cancers, primarily breast cancer and cervical cancer, while actually providing protection against others, such as endometrial and ovarian cancers, as supported by recent studies 1. The breast cancer risk is slightly elevated during active use and for about 10 years after stopping COCs, with an estimated 1 additional case per 7,690 women using COCs for one year. Cervical cancer risk increases with longer duration of use but decreases after discontinuation. Importantly, COCs significantly reduce the risk of endometrial and ovarian cancers, with protection lasting for decades after discontinuation, as noted in a study published in the Journal of the National Comprehensive Cancer Network 1. For those concerned about cancer risks, several alternatives exist, including non-hormonal options like copper IUDs (ParaGard), barrier methods (condoms, diaphragms), and fertility awareness methods. Hormonal alternatives with potentially lower systemic effects include progestin-only pills (Micronor, Camila), hormonal IUDs (Mirena, Kyleena, Skyla), implants (Nexplanon), and injections (Depo-Provera). The cancer risk profile varies by contraceptive method, with progestin-only options generally not associated with increased breast cancer risk. When choosing contraception, consider personal and family cancer history, age, smoking status, and other health factors, as recommended by guidelines from the U.S. Centers for Disease Control and Prevention 1 and the National Comprehensive Cancer Network 1. The absolute cancer risk from COCs remains very small for most women, and benefits often outweigh risks, but individual risk assessment with a healthcare provider is essential, particularly for women with a history of breast cancer or other hormonally mediated cancers 1.

Some key points to consider:

• COCs may increase the risk of breast cancer, particularly in women under 34 years of age, as noted in a study published in the Journal of the American Academy of Dermatology 1.
• COCs may increase the risk of cervical cancer, particularly with longer duration of use, but this risk decreases after discontinuation.
• COCs significantly reduce the risk of endometrial and ovarian cancers, with protection lasting for decades after discontinuation.
• Alternatives to COCs, such as progestin-only pills and hormonal IUDs, may have a lower risk profile for certain cancers.
• Individual risk assessment with a healthcare provider is essential to determine the best contraceptive option for each woman.

In terms of specific cancer risks, a study published in the Journal of the National Comprehensive Cancer Network found that COCs reduced the risk of ovarian cancer by 45%–50% in carriers of a pathogenic BRCA1 variant and by 60% in carriers of a pathogenic BRCA2 variant 1. Another study published in the Annals of Oncology found that COCs decreased the risk of endometrial neoplasia in pre-menopausal and peri-menopausal women 1. Overall, the decision to use COCs or alternative contraceptive methods should be based on individual risk assessment and consideration of personal and family cancer history, age, smoking status, and other health factors.

From the Research

Cancer Risks Associated with Combined Oral Contraceptives (COCs)

• The use of COCs has been associated with a higher risk of breast cancer, with studies suggesting that current use is linked to an increased risk of invasive breast cancer 2, 3.
• The risk of breast cancer appears to be higher for longer durations of COC use, with one study finding that current use of COCs for more than 5 years was associated with a higher risk of breast cancer compared to never use 3.
• However, the risk of breast cancer seems to decrease after stopping COC use, with one study finding that the risk was similar to that of never users 5 years after cessation 3.
• COCs have also been found to reduce the risk of certain cancers, including endometrial, ovarian, and colorectal cancer, with these benefits persisting for at least 30 years after stopping use 4.

Alternatives to Combined Oral Contraceptives

• Other forms of contraception, such as intrauterine devices (IUDs) and subdermal implants, have been found to have higher effectiveness and lower risks compared to COCs 5.
• Progestin-only and nonhormonal methods, such as implants and condoms, are associated with rare serious risks and may be a suitable alternative for women who are concerned about the cancer risks associated with COCs 5.
• Extended-cycle oral contraceptives, which contain lower doses of hormones, may also be an option for women who want to use a hormonal method but are concerned about the risks associated with traditional COCs 6.

Factors to Consider When Choosing a Contraceptive Method

• When selecting a contraceptive method, women should consider their individual risk factors, medical history, and personal preferences 5.
• Clinicians should discuss the patient's tolerance for risk of pregnancy, menstrual bleeding changes, and other risks, as well as their personal values and preferences, to determine the most suitable contraceptive method 5.