Patient choice, contraceptive effectiveness, and medical eligibility all need to be incorporated into the contraceptive counseling for reproductive-age women who have cancer or are in remission. Based on these principles, women can minimize the risk of an unintended pregnancy, continue to receive necessary adjuvant or preventive therapy, and maintain high levels of contraception satisfaction.
The Centers for Disease Control and Prevention (CDC) has published medical eligibility criteria (MEC) to assist providers in selecting medically appropriate contraception for women with various health conditions, including cancer (MMWR Recomm. Rep. 2010;59(RR-4):1-6).
Certain classes of hormonal contraception are contraindicated in specific cancer types. It is important to note that the copper intrauterine device (ParaGard) is very effective (with a first-year failure rate of 0.8%) and has no cancer-related contraindications. Any contraceptive with estrogen or progesterone is relatively contraindicated in hormonally mediated cancers, including breast, endometrial, or other cancers that have estrogen (ER) or progesterone (PR) positive receptors. Combined hormonal contraception is contraindicated even in breast cancers that are ER/PR negative for the first 5 years, after which they are CDC MEC category 3 (risks likely outweigh the benefits).
Venous thromboembolism (VTE) is an important cancer-related morbidity. Active cancer increases the risk of VTE by fourfold, which is further increased if the patient is on chemotherapy (Arch. Intern. Med. 2000;160:809-15). Estrogen is known to increase thrombotic risk, and therefore it is contraindicated in any patient at risk for VTE or with a history of a VTE. There is some debate about the use of progestin-only contraceptives in those at risk of (or with a history of) VTE. The best evidence and CDC guidelines indicate that progestin-only methods can be used in patients with cancer or with a history of VTE. Importantly, no known association exists between emergency contraception and VTE (Obstet. Gynecol. 2010;115:1100-9).
Other cancer-specific problems that may impact contraception include thrombocytopenia, gastrointestinal side effects, and drug interactions. Thrombocytopenia may exacerbate or cause abnormal uterine bleeding. Therefore, menstrual suppression with continuous combined hormonal contraception or progestin-only methods, including the hormonal IUD and implant, may be ideal. Regarding gastrointestinal side effects, emesis and mucositis from cancer and treatment may reduce absorption of oral contraceptives, so alternatives should be considered. Antacids, analgesics, antifungals, anticonvulsants, and antiretrovirals are all known to affect hepatic metabolism and may affect oral contraceptive efficacy.
Given the possibility of chemotherapy-induced immunosuppression, there is a theoretical concern about the infectious risk of an indwelling foreign body such as an IUD or implant. The best evidence to date, however, does not support an increased risk, even in the setting of neutropenia. Chemotherapy also increases osteoporosis. Gynecologists should use caution with depot medroxyprogesterone acetate (DMPA), although there is no absolute contraindication, especially for shorter durations of use.
Many breast cancer patients are prescribed tamoxifen as adjuvant therapy, but the antiestrogenic effects of tamoxifen may not prevent pregnancy (Cancer Imaging 2008;8:135-45). Therefore, it is critical for reproductive-age women taking tamoxifen to be given effective contraception. Experts have not reached a consensus on the use of levonorgestrel intrauterine systems (LNG-IUS, Mirena, or Skyla) in the setting of breast cancer.
On the one hand, patients on long-term tamoxifen may benefit from the endometrial protective effect of an LNG-IUS (Lancet 2000;356:1711-7). It is uncertain if women with an LNG-IUS in place at the time of breast cancer diagnosis should have the device removed. Placing a LNG-IUS is contraindicated in all cases of active cancer, but if the patient has no evidence of disease for more than 5 years, the CDC lists the LNG-IUS as category 3. Expert consensus is that studies are needed with LNG-IUS use in women with breast cancer and that use of the LNG-IUS in this population should be made with careful consideration of the risks and benefits (Fertil. Steril. 2008;90:17-22; Contraception 2012;86:191-8).
Physicians should consider the contraceptive needs of women who are actively being or have recently been treated for cancer, as 17% of female cancers occur in women of reproductive age. The copper IUD is a highly effective option with very few contraindications. In patients with a history of non–hormonal related cancer (and without any history of VTE), all contraceptive options can be considered, including those containing estrogen. Estrogen-containing contraceptives should be avoided in those with a history of hormonally related cancers. Those not familiar with the wide array of options should consider referring early, and family planning specialists should consider medical eligibility while counseling women about the most effective contraceptive options.
Dr. Zerden is a family planning fellow in the department of obstetrics and gynecology at the University of North Carolina at Chapel Hill. He reported having no financial disclosures. E-mail Dr. Zerden at obnews@frontlinemedcom.com.
