Media reports on OC studies raise flags: How to advise patients?

Evidence supports that the Pill is a safe, effective contraceptive

Has the telephone been ringing in your office with questions from patients who are concerned about using oral contraceptives in light of media reports questioning the Pill's safety? If so, you are not alone. What are you doing to help women place such news in proper context?

The first flurry of media activity came with the publication of a study linking oral contraceptive use and increased risk of cervical cancer.1 More media reports were issued with the presentation of a paper at a recent American Heart Association (AHA) conference which indicated that long-term use of oral contraceptives might increase arterial plaque that can raise the risk of heart disease.2 News from the AHA conference was widely disseminated, with all three major networks reporting on the paper.

The Association of Reproductive Health Professionals (ARHP) has compiled basic talking points to help clinicians address patient concerns. [The talking points are available.]

"The ARHP community is committed to evidence-based medicine, and misinterpretations of clinical research and sensationalized reporting can have a negative impact on public health," states a letter cosigned by Beth Jordan, MD, medical director, and Wayne Shields, president and CEO.

The Planned Parenthood Federation of America (PPFA) also has issued guidance for its affiliates in light of the AHA presentation. The PPFA and ARHP guidance are designed to help clinicians discuss the benefits and risks of oral contraceptive (OC) use with their patients.

"Our message is to communicate to our patients that their health and safety are our top priorities and that the Pill continues to be a safe, effective method of birth control," says the PPFA.

Is Pill use a heart risk?

The paper presented at the AHA conference found that women who use the Pill for 13 years or more had an unexpected increase in the presence of artery-clogging plaque in blood vessels found in the neck and leg. The study also found that women who stopped using the Pill were at increased risk for more plaque.

While in theory, an increase in plaque may mean a higher rate of stroke or heart attack, no existing, scientifically sound studies of oral contraceptive users have shown any excess cases of stroke or heart attack than among low-dose oral contraceptive users, advises the PPFA. Of the myriad oral contraceptive studies done in the past, none has found that the Pill is associated with increased risk of heart disease after pill discontinuation, the PPFA guidance states.

To place the rare risks of heart attack and stroke among OC users in perspective, the PPFA presents the following statistics:

  • For nonsmoking women in their 20s who are not on oral contraceptives, the risk of heart attack is 0.01 per 100,000 woman-years of use, and the risk of stroke is 1.9 per 100,000 woman-years of use.
  • For nonsmoking women in their 20s who are taking oral contraceptives, the risk of heart attack is 0.02 per 100,000 woman-years of use, and the risk of stroke is 2.2 per 100,000 woman-years of use.
  • For smokers in their 30s who are not on oral contraceptives, the risk of heart attack is 1.4 per 100,000 woman-years, and the risk of stroke is 6.8 per 100,000 woman-years.
  • For smokers in their 30s who are taking oral contraceptives, the risk of heart attack is 2.04 per 100,000 woman-years, and the risk of stroke is 10.2 per 100,000 woman-years.

The bottom line is that the baseline expected number of events is very small among oral contraceptive users, states the PPFA. Smoking and advancing age are all larger risk factors than oral contraceptive use. No study has shown an increase in these baseline expected numbers of serious cardiovascular events, states PPFA.

Neither providers nor patients should change their behaviors with respect to oral contraceptives in light of this new data, adds PPFA.

"Researchers have told the media that more data is needed and that women and providers should not panic," states the guidance. "Instead, women should speak with their health care providers about their risk factors for heart disease and pay close attention to modifying the big risk factors for cardiovascular disease, such as smoking, uncontrolled hypertension, obesity, high cholesterol, and poorly managed diabetes mellitus."

OCs: cervical cancer risk?

Information on a possible link between OC use and cervical cancer risk comes from analysis of data from 24 worldwide studies.2 Among current users of oral contraceptives, the risk of invasive cervical cancer increased with increasing duration of use, results suggest. The analysis showed relative risk for five or more years' use vs. never use at 1.90 (95% confidence interval 1.69-2.13). The risk declined after use ceased, and by 10 or more years, had returned to that of never users, the analysis indicates. A similar pattern of risk was seen for invasive and in-situ cancer, and in women who tested positive for high-risk human papillomavirus. Relative risk did not vary substantially between women with different characteristics.

Analyses performed in the new publication were routinely stratified by age at first intercourse (younger than 18 years, 18-20 years, and 21 years or older), number of full-term pregnancies (zero, 1-2, 3-4, and five or more), lifetime number of sexual partners (one, 2-5, and six or more), smoking (never, past, and current), and screening status (ever or never likely to have had a previous Pap smear). Those with missing information on any of these adjustment factors were assigned to a separate stratum for the relevant variable; sensitivity analyses were done excluding women or studies with missing adjustment variables, the researchers state.1

What should clinicians take away from this research? According to the ARHP, the study shows that long term use of oral contraceptives (more than five years) is associated with an increased risk of cervical cancer. The study also reports that when a woman stops taking oral contraceptives, her risk fades over time and returns to normal after 10 years, notes the ARHP.

In comparison, the benefits of oral contraceptives have been widely documented, states the ARHP. For example, women who use OCs for 10 or more years have a significant decrease in risk of ovarian and endometrial cancer. "While this study shows a slight increased risk of cervical cancer, the risk is still very low," states the ARHP. "An increase in the incidence of a rare event remains a rare event."

Advise women who are concerned about the risks for cervical cancer to use condoms, consider human papillomavirus (HPV) screening and HPV vaccine, obtain regular Pap smears, and avoid smoking, the ARHP guidance states.

Use peer-reviewed curricula on cervical cancer and understanding risk associated with hormonal contraception developed by the ARHP. The association offers two online resources, Managing HPV: A New Era in Patient Care and You Decide: Making Informed Health Choices about Hormonal Contraception, which are both available at no cost at the ARHP web site, www.arhp.org.

References

  1. International Collaboration of Epidemiological Studies of Cervical Cancer. Cervical cancer and hormonal contraceptives: Collaborative reanalysis of individual data for 16,573 women with cervical cancer and 35,509 women without cervical cancer from 24 epidemiological studies. Lancet 2007; 370:1,609-1,621.
  2. Rietzschel E, De Buyzere M, De Baquer D, et al. Anticonceptive drug use and increased carotid and femoral plaque prevalence: Population data from Asklepios. Presented at the American Heart Association conference. Orlando, FL; November 2007.