The World Health Organization (WHO) and the United Nations Children’s Fund (UNICEF) recommend breastfeeding infants in the first hour of their life, exclusively for the first 6 months of their life, and supplementally for as long as 2 years and beyond.

While many are familiar with the positive health benefits to infants—lowered risk of obesity, asthma, sudden infant death syndrome (SIDS), ear and respiratory infections, diabetes, and gastrointestinal infections among others—few are familiar with breastfeeding’s health impacts on the mother.

Not only does it lower a mother’s risk of type 2 diabetes and high blood pressure, but it also reduces risk of breast cancer and ovarian cancer. But for breast cancer survivors, patients in treatment, or previvors on a high-risk early detection plan, breastfeeding is often a challenge. Here are 5 of the most important ways that breastfeeding impacts cancer diagnoses.

1. Breastfeeding Helps Prevent Breast Cancer

Breast cancer is the most commonly diagnosed cancer in the world. It’s important to know all the risk factors for this deadly disease, but in a recent CDC survey, less than 1 in 4 people knew that mothers were less likely to develop breast cancer later in life if they breastfed their babies. Echoing those numbers, only 1 in 4 babies are still being exclusively breastfed at the age of 6 months, despite recommendations from the WHO and the American Academy of Pediatrics (AAP).

The truth is that, compared to women who have never breastfed, breastfeeding mothers reduce their overall risk of breast cancer by 10% and reduce their risk by a whopping 28% for the notoriously hard-to-treat triple-negative breast cancer.

While the relationship between breastfeeding and breast cancer risk is not fully understood, many researchers believe it is related to a woman’s lifetime exposure to sex hormones, which are drastically altered during the course of pregnancy and lactation.

2. Breastfeeding Reduces the Risk of Ovarian Cancer

Much like breast cancer and as a result of the same hormonal mechanism, ovarian cancer risk levels are highly impacted by breastfeeding. Compared to women who have never breastfed, mothers who breastfeed have a 24% lower risk of invasive ovarian cancer, according to a 2020 pooled analysis of over 13,000 cases. Women who fed longer and more recently were also shown to have a further decrease in risk.

With a 5-year survival rate of only 48% for invasive epithelial ovarian cancer, the protection benefits of breastfeeding should not be discounted.

3. Can You Breastfeed During Breast Cancer Treatments?

For breastfeeding mothers recently diagnosed with breast cancer, often one of the first questions is, can I still breastfeed my baby while undergoing breast cancer treatment?

While there are many things that can be passed through breast milk, breast cancer is not one of them. Nor can you pass your genes, such as the mutated “breast cancer gene” BRCA, through your breast milk. Family history and genes were passed the day your baby were conceived.

Less Stress for Women Who Know Their Genetic Risk for Breast Cancer

That being said, some breast cancer treatments like chemotherapy drugs, immunotherapy drugs, and prevention drugs like tamoxifen, will be passed to your baby and you should avoid breastfeeding if you are on those treatment programs. Alcohol and nicotine, two risk factors for breast cancer, should also not be consumed in excess or immediately preceding a feeding.

Radiation therapy with external beams are usually okay for breastfeeding, but milk duct tissue might be too damaged to be productive. When in doubt, always ask your doctor if breastfeeding is still appropriate for your treatment plan.

4. Can You Breastfeed After Mastectomies?

Women with early-stage breast cancer can sometimes be treated with only a mastectomy, the surgical removal of the cancerous breast. Some women who are at extremely high risk for breast cancer even choose to get a risk-reducing mastectomy to prevent a diagnosis. Because mastectomies involve the complete removal of the milk duct tissue, milk cannot be produced from the removed breast. For this reason, women who’ve had a double mastectomy, the removal of both breasts, cannot breastfeed.

For those who have had only one breast removed (a unilateral mastectomy), milk can be produced as normal in the other breast, although additional steps might need to be taken to increase production to keep up with the demands of a hungry infant.

Women who have undergone lumpectomies, the removal of a portion of the breast, can have varying degrees of success with breastfeeding depending on how much tissue and from which area the breast tissue was removed.

5. Breastfeeding & Breast Cancer Early Detection

Cancer Screenings: When & Who Should Get Lung, Colorectal, Cervical & Breast Cancer Tests

Many women skip regular mammograms during breastfeeding, and understandably. Not only is the first year after a child’s birth overwhelming, but breasts are often incredibly tender. We’re here to tell you, though, that not only are mammograms during breastfeeding not dangerous, but they’re important.

While mammograms during pregnancy are safe for the fetus, it’s not the best time to do them, so chances are, most breastfeeding women are overdue for a mammogram. In addition, breasts go through a lot of changes during pregnancy and breastfeeding. A screening mammogram can catch cancerous changes.

Breast Ultrasounds: Why, How & When They’re Done

In addition to a mammogram, don’t forget your monthly breast self-exam. A self-exam is a quick, free and easy way to keep on top of the changes in your breasts and what is normal for your body. Although your body is changing substantially in this period, doing a breast self-exam is an important way to keep up-to-date on those changes. A significant number of women report that their first sign that something was wrong was a lump that they found themselves.

Need support or have questions? Whether you are someone at high risk, a current patient, survivor or family member, SHAREing & CAREing is here for you. We are a non-profit organization founded and run by cancer survivors and thrivers. Contact us for individual support, attend a monthly support group meeting or join our online Facebook group. We offer free patient navigation services, links to free and reduced cost medical care, transportation assistance, and educational prevention workshops offered to schools and the community.

SOURCES

• “Breastfeeding,” World Health Organization (WHO)
• “Breastfeeding: Why It Matters,” Centers for Disease Control and Prevention (CDC)
• “Public Opinions About Breastfeeding,” Centers for Disease Control and Prevention (CDC)
• “Breastfeeding and the Use of Human Milk,” Pediatrics, 2012
• “Breastfeeding and Breast Cancer Risk by Receptor Status—A Systemic Review and Meta-Analysis,” Annals of Oncology, 2015
• “Association Between Breastfeeding and Ovarian Cancer Risk,” Journal of the American Medical Association, 2020