Breast Cancer and Breastfeeding: Did You Know …?
Updated: Oct 21
It’s October … leaves falling, jack-o-lanterns carved, pumpkin spice everything … and pink ribbons. Despite being overshadowed by the current worldwide pandemic, Breast Cancer Awareness Month (signified by the pink ribbon) is still the celebrated cause this month.
very few women got this information from their healthcare provider (only around 17% of the sample)
A recent study showed that while some moms are aware that breastfeeding can reduce the risk of breast cancer (a little more than half of the women surveyed realized this), very few women got this information from their healthcare provider (only around 17% of the sample) (Ganju et al 2018). So this is an important topic obstetricians, midwives, childbirth educators and lactation consultants may want to add to their conversations with pregnant moms.
researchers in Sweden found that breastmilk was actually causing tumor cells to die...
So let’s get to the nitty gritty – how exactly is breastfeeding protective? Did you know …
In a laboratory environment, breastmilk kills cancer cells. In a sort of laboratory accident, researchers in Sweden found that breastmilk was actually causing tumor cells to die. After further investigation, they learned that breastmilk contains a compound nicknamed HAMLET (which stands for Human Alpha-lactalbumin Made LEthal to Tumor cells) that will not attack healthy cells but will instead invade tumor cells and cause changes that lead to apoptosis or programmed cell death. While their testing in animals has been difficult, their research certainly shows the amazing potential of breastmilk.
Some people with cancer are using breastmilk as part of their treatment. Because of the promising HAMLET research, cancer patients are wondering if consuming breastmilk as a part of their treatment regimen could help. While there’s no current evidence to support this practice, some people think it could boost a patient’s immunity when they are undergoing chemotherapy.
Breastfeeding can decrease the risk of breast cancer, and the more months you breastfeed the more protected you are.
The longer you breastfeed, the more protection you get. Breastfeeding can decrease the risk of breast cancer, and the more months you breastfeed the more protected you are. A 2002 study published in The Lancet showed a 4.3% reduction in breast cancer risk for every 12 months of breastfeeding. Another study showed that breastfeeding itself, no matter how long, decreased the risk 22% when compared to no breastfeeding at all. When comparing the length of breastfeeding, risk reduction increased as the number of months of breastfeeding increased.
If you have a family history of breast cancer, your risk is reduced by breastfeeding your babies. Researchers found that if a women breastfeeds and has a parent or sibling with breast cancer, her own risk of premenopausal breast cancer was significantly lower.
Breastfeeding may protect women from specific subtypes of breast cancer. If you know that you carry the BRCA gene, breastfeeding may be the best choice for you. Researchers found that breastfeeding for one year provided a 32% reduction in risk for breast cancer, and breastfeeding for 2 or more years increased the risk reduction. They caution, however, this was only for the BRCA1 type and not the BRCA2 gene. In addition, ever breastfeeding seems to be protective against hormone receptor-negative breast cancers. These types of breast cancer seem to happen more often for younger women and African Americans, and tend to have poorer outcomes.
If you have had breast cancer, breastfeeding reduces the risk of cancer related mortality. In a 20-year follow-up, a recent study concluded “A total breastfeeding history >6 months and pregnancy are associated with both greater overall and breast cancer–specific survival for women diagnosed with breast cancer, having lived long enough for other causes of death to contribute substantially to mortality.”
But if you developer a lump that doesn’t go away, if the lump feels fixed in place (as opposed to moveable), or if the skin of the breast is puckered (and looks like orange peel), you should seek the advice of your healthcare provider.
While breastfeeding does reduce the risk of breast cancer, it doesn’t completely eliminate the possibility. Your breasts may feel lumpy when the glands fill with milk. But if you developer a lump that doesn’t go away, if the lump feels fixed in place (as opposed to moveable), or if the skin of the breast is puckered (and looks like orange peel), you should seek the advice of your healthcare provider. Mammograms can be done on the lactating breast – the emptier the breast before the procedure, the better. Ultrasound and MRI are also compatible with a milk filled breast. Both biopsy and surgery can be done even if mom is lactating. A cancer diagnosis while breastfeeding may mean weaning – working closely with a lactation consultant as a part of your care team will help during such a difficult situation.
Anand P, Kunnumakara AB, Sundaram C, Harikumar KB, Tharakan ST, Lai OS, Sung B, Aggarwal BB. (2008). Cancer is a Preventable Disease that Requires Major Lifestyle Changes. Pharmaceutical Research, 25(9), 2097–2116. http://doi.org/10.1007/s11095-008-9661-9.
Anstey, E. H., Shoemaker, M. L., Barrera, C. M., O’Neil, M. E., Verma, A. B., & Holman, D. M. (2017). Breastfeeding and breast cancer risk reduction: implications for black mothers. American journal of preventive medicine, 53(3), S40-S46.
Chowdhury, R., Sinha, B., Sankar, M. J., Taneja, S., Bhandari, N., Rollins, N., Bahl, R. and Martines, J. (2015), Breastfeeding and maternal health outcomes: a systematic review and meta-analysis. Acta Paediatr, 104: 96–113. doi:10.1111/apa.13102
Ganju, A., Suresh, A., Stephens, J., Palettas, M., Burke, D., Miles, L., ... & Ramaswamy, B. (2018). Learning, Life, and Lactation: Knowledge of Breastfeeding's Impact on Breast Cancer Risk Reduction and Its Influence on Breastfeeding Practices. Breastfeeding Medicine, 13(10), 651-656.
HAMLET, a new concept for cancer therapy. http://www.med.lu.se/english/department_of_laboratory_medicine/mig/research_groups/the_svanborg_group/the_hamlet_project
Johnson, H. M., Mitchell, K. B., & Academy of Breastfeeding Medicine. (2020). ABM Clinical Protocol# 34: Breast Cancer and Breastfeeding. Breastfeeding Medicine.
Kotsopoulos J, Lubinski J, Salmena L, Lynch HT, Kim-Sing C, Foulkes WD, ... & Ainsworth, P. (2012). Breastfeeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers. Breast Cancer Research, 14(2), 1.
Lööf-Johanson Margaretha, Brudin Lars, Sundquist Marie, and Rudebeck Carl Edvard. (2016). Breastfeeding Associated with Reduced Mortality in Women with Breast Cancer. Breastfeeding Medicine, 11(6): 321-327. doi:10.1089/bfm.2015.0094.
Palmer JR, Viscidi E, Troester MA, Hong C, Schedin P, Bethea TN, Bandera EV, Borges V, McKinnon C, Haiman CA, Lunetta K, Kolonel LN, Rosenberg L, Olshan AF, Ambrosone CB, (2014). Parity, Lactation, and Breast Cancer Subtypes in African American Women: Results from the AMBER Consortium. JNCI J Natl Cancer Inst 106 (10): dju237. doi: 10.1093/jnci/dju237
Stuebe AM, Willett WC, Xue F, Michels KB. (2009). Lactation and Incidence of Premenopausal Breast Cancer A Longitudinal Study. Arch Intern Med. 169(15):1364-1371. doi:10.1001/archinternmed.2009.231
Svanborg C, Ågerstam H, Aronson A, Bjerkvig R, Düringer C, Fischer W, Gustafsson L, Hallgren O, Leijonhuvud I, Linse S, Mossberg AK, Nilsson H, Pettersson J, Svensson M. (2003). HAMLET kills tumor cells by an apoptosis-like mechanism—cellular, molecular, and therapeutic aspects. Advances in cancer research, 88, 1-29.