Decisive new data on risks and benefits of hormonal contraception will change how we manage many patients. These findings prompted the American College of Obstetricians and Gynecologists (ACOG) to update its practice bulletin (released in June) on hormonal contraception in women with coexisting medical conditions.1 Among the most notable areas of change:
- Family history of breast cancer or BRCA1 or 2 mutations. Combination oral contraceptives (OCs) do not appear to increase the risk of breast cancer in these women, and do help prevent ovarian cancer.
- Concomitant medications. More women are using enzyme-inducing anticonvulsants for conditions other than seizure disorders; some affect steroid levels.
- Obesity. Progestin-only and intrauterine methods may be better for obese women older than 35 years, who face an elevated baseline risk of venous thromboembolism.
- Lupus. Combination OCs are safe in women with stable, mild disease who are seronegative for antiphospholipid antibodies.
- Depot medroxyprogesterone acetate (DMPA). Although bone density declines in women using DMPA, it recovers within 3 years after the drug is discontinued.
- Patch and ring. Until method-specific data come in, assume that the patch and ring have the same contraindications as combination OCs.
For the fine points on these and other findings, we talked with Dr. Andrew M. Kaunitz, who assisted ACOG with preparation of the new bulletin.1
1. Breast cancer risk
OCs do not add to existing high risk
OBG Management: Women who have a family history of breast cancer have a higher-than-average risk of developing the cancer themselves, and it is widely assumed that estrogen further heightens that risk. Should these women avoid combination OCs?
KAUNITZ: No. Although these women have been reluctant to use hormonal contraceptives (as have many caregivers), we now have several lines of reassuring evidence.
Among the studies demonstrating safety of hormonal methods in this population is the 2002 Women’s CARE study, conducted by the Centers for Disease Control and Prevention and sponsored by the National Institute of Child Health and Human Development, which found no elevated risk of breast cancer in women currently or formerly using OCs, compared with women who had never used them.
This study compared 4,575 women who had breast cancer with 4,682 controls. The relative risk of breast cancer was 1.0 (95% confidence interval 0.8–1.3) among current OC users and 0.9 (0.8–1.0) among women who had previously used OCs. The relative risk did not increase consistently with higher doses or longer use.2 Nor did use of OCs add risk in women with a family history of breast cancer.2
OBG Management: An editorial accompanying that study said: “The importance of this finding for public health is enormous, because more than 75% of the women in the study had used oral contraceptives.”3
KAUNITZ: Yes, but this does not mean that women with a positive family history have no increased risk of breast cancer—they do. Rather, the use of hormonal contraceptives does not augment that risk further.
OBG Management: What about women with other high-risk factors, such as germline mutations? Do OCs increase their risk of breast cancer?
KAUNITZ: No. In the largest study to date of breast cancer risk associated with prior or current OC use in women 35 to 64 years of age with BRCA1 and 2 mutations, low-dose OC formulations did not increase it.4 In fact, OC use was associated with a significantly reduced risk of breast cancer in BRCA1 mutation carriers (odds ratio 0.22; 95% confidence interval 0.10–0.49).4
Pill reduces risk of ovarian cancer in BRCA carriers
KAUNITZ: It is also important to remember the higher risk of ovarian cancer in women with BRCA mutations. We now know that use of the Pill reduces ovarian cancer risk in BRCA-positive women, just as it does in the general population. In a study involving 451 women with BRCA1 or 2 mutations, who self-reported their lifetime history of OC use (or nonuse), the odds ratio for ovarian cancer associated with OC use for a minimum of 1 year was 0.85 (95% confidence interval 0.53–1.36) and declined by 5% (1%–9%) with each additional year of use (P for trend=.01). Use for 6 years or more carried an odds ratio of 0.62 (0.35–1.09).5