Breast Cancer Screening During Lactation
by Anne Eglash MD, IBCLC, FABM
Breast cancer screening recommendations vary across many professional organizations, and according to the authors of this week’s article, there are few guidelines on breast cancer screening for lactating women. Because the average age of first childbirth has steadily risen in the USA, there is an increasing number of breastfeeding mothers who are eligible for breast cancer screening based on age and risk.
Historically, we told breastfeeding women at average risk of breast cancer, who are eligible for breast cancer screening, to wait 2-6 months after weaning to have a mammogram, but that has changed. As the authors point out, breast cancer is the most common malignancy among reproductive-aged women, therefore we need to address timely breast cancer screening, so that breastfeeding women are not at higher risk of morbidity/death due to later diagnosis. Further, postpartum women, breastfeeding or not, have a heightened risk of biologically aggressive breast cancer for 10 years after childbirth. Therefore, the authors recommend that all women, including breastfeeding women, who are at average risk of breast cancer, undergo annual screening starting at age 40, even if they have not yet weaned. This is the recommendation by the American College of Radiology, the National Comprehensive Cancer Network, and the American Society of Breast Surgeons.
To be clear, there are other recommendations out there from the American College of Obstetrics and Gynecology, the American Cancer Society, and the US Preventive Services Task Force, all of which are less aggressive screening recommendations.
The recommendations are different for women at higher-than-average risk of breast cancer, which we are not addressing here.
- Breast MRI and breast ultrasound are equally appropriate as mammography for breast cancer screening among lactating women at average risk of breast cancer.
- Longer duration of breastfeeding is associated with a decreased risk of developing breast cancer in women with the gene mutation BRCA.
- Lactating women should pump and dump their milk for 12 hours after having a breast MRI, due to the infant risk from intravenous gadolinium, which is the MRI contrast.
- Pumping or breastfeeding before a mammogram helps to decrease the density of breast images, making interpretation easier.
- The American College of Radiology recommends that lactating women have 3-D mammograms, also known as digital breast tomosynthesis, rather than 2D mammography.
- Women who undergo mammography during lactation are at higher risk of needing biopsies due to the presence of microcalcifications related to lactation.
See the Answer
Breast cancer is the most common malignancy among reproductive-aged women, and an increasing number of women are breastfeeding at the time of screening initiation. The literature was reviewed to identify evidence-based guidelines for breast cancer screening during lactation. Health care providers should consider routine age-related or high-risk screening; they should also discuss alternate surveillance strategies, including deferment until cessation of breastfeeding. Shared decision-making and individualized patient care should involve consideration of the limitations of current evidence. Lactation-related radiographic changes may make examination interpretation more challenging; preprocedure milk expression and use of particular supplemental imaging modalities can improve examination sensitivity. Despite these strategies, breastfeeding women may have higher rates of false-positive findings and therefore undergo more biopsies. However, given the increased risk of biologically aggressive breast cancers in postpartum women, these risks may be outweighed by the benefits of routine breast cancer screening for breastfeeding women.
This summary is an excellent article to share with colleagues about breast cancer screening for lactating women at average risk of breast cancer. The authors make the point that pregnancy increases the risk of breast cancer postpartum and this risk is heightened for 10 years. Therefore, it may be deleterious to delay breast cancer screening in postpartum women for the sake of obtaining clearer images after weaning. This is a topic that ought to be addressed in our breastfeeding medicine/lactation practices, since some women who are in the cycle of pregnancy/lactation are not seeing their primary care providers for routine health care maintenance. Not only should we pick up on women who have a family history of breast cancer and refer them for evaluation regarding optimal screening schedules, but we should share the recommendation that lactating women 40 and older, who are at average risk, obtain annual mammograms.