Dr. Sherene Loi, a medical oncologist and clinician scientist at the Peter MacCallum Cancer Centre led the original study. These studies identify breastfeeding as one of the most effective ways for women to reduce their risk of breast cancer. In Australia, almost 60 women are diagnosed with breast cancer each day. This further widens the gap, making breast cancer now the second-most diagnosed cancer in the country and the most common diagnosed cancer among women. This new research is helping to understand how maternal factors — in this case, specifically through breastfeeding and childbirth — can play a role in cancer prevention.
This study suggests that mothers of breastfed children produce more specialized immune cells.
Warriors at the Wound
These immune cells, called T cells, commonly enter women’s cancerous breast tissue. These T cells function as sentinels, patrolling tissues for precursors to cancerous cells. Dr. Loi’s findings indicate that for every child a woman has, it makes her about 7 percent less likely to develop breast cancer. Plus when moms breastfeed for at least five months that reduces that risk by another 2 percent.
Understanding Breast Cancer Statistics
Breast cancer is still the most serious health issue for Australian women with close to 20,000 diagnosed each year. This inflammatory stat underlines the need for demonstrated preventative approaches and treatment. Addressing Intersectional Health Issues While breast cancer disproportionately affects women of color, young women are at an even greater risk of developing triple-negative breast cancer. This aggressive subtype is most well known for missing the three usual receptors found on breast cancer cells.
Dr. Loi underscores the disproportionate burden of triple-negative breast cancer on African American women. This problem might be related to things such as their reproductive behaviors, including childbearing patterns, and decreased breastfeeding. “Some of the highest rates of breast cancer,” Dr. Loi noted, “are seen in populations with fewer breastfeeding practices.” This strong and consistent correlation between BF and health outcomes supports continued investment in breastfeeding promotion as a cost-effective public health intervention.
“This led scientists to suspect that child-rearing and breastfeeding were protective, while being nulliparous [never given birth] was a risk factor.” – Sherene Loi
The implications of these findings are profound. By unveiling the biological mechanisms underlying breastfeeding, researchers can open new doors for preventing and treating breast cancer. This expertise makes clear the protective effects breastfeeding provides against the disease.
The Role of T Cells in Cancer Defense
The research points to T cells as key drivers in the body’s immune response to thwart possible cancer formation. These protective, specialized cells are found in greater numbers and density in the breast tissue of women who have breastfed. This finding is in accordance with ample research connecting immune function to cancer prevention.
Dr. Nicholas Huntington, a colleague of Dr. Loi, remarked, “What this study enables us to do is get a better understanding of the immune cell types, some of the growth factors and signaling molecules that might be more important to target with emerging therapies.” This finding may hold the key to new treatment strategies and preventive measures for breast cancer.
“We know we can treat cancer with immunotherapies, but now we can move into prevention. So for breast cancer, it’s not just about hormones, but about our immune system.” – Sherene Loi
These results should encourage efforts to reduce breast cancer risks by increasing breastfeeding. As Dr. Loi cautions, breastfeeding should not be viewed as the sole and assured solution. “Even if women do breastfeed, it’s not a 100 percent guarantee that [they’re] not going to get breast cancer. It’s a population-level effect,” she explained.
Implications for Public Health and Future Research
This research is a step in a very promising direction with strong implications for public health initiatives looking to improve rates of breastfeeding among new mothers. Dr. Loi supports comprehensive strategies to protect and promote breastfeeding as part of a holistic approach to improving breast health. “We can motivate breastfeeding to improve breast health … and we can develop vaccines and immune strategies to mimic this [natural] protection,” she stated.
“In addition, as Dr. Loi underscores, support systems need to be flexible in order to adapt to women’s varying situations when it comes to breastfeeding. Obviously breastfeeding is one option among many. Women’s preferences and circumstances vary, and there are structural issues … workplace policies, medical issues, and support,” she said.
Beyond its findings, the study suggests next steps for research. Scientists are now working to better understand the relationship between pregnancy and lactation and the different forms of breast cancer. As they learn more, specific therapies could be developed that mimic the protective effects found in women who have had children and breast-fed those children.
“So [having] more children … has to be associated with more breastfeeding for that risk reduction [to occur], specifically against triple-negative breast cancer,” – Sherene Loi
