Researchers have discovered that high levels of prolactin receptors in triple negative breast cancer makes the tumor much less aggressive. They suggest that breastfeeding, linked to the release of the hormone prolactin, might actually protect some women from breast cancer and be used in future treatments.
The study, “Prolactin Pro-Differentiation Pathway in Triple Negative Breast Cancer: Impact on Prognosis and Potential Therapy,” recently appeared in the journal Scientific Reports. The finding could spare women from harsh treatments frequently used for this type of cancer.
“We think this could be a revolutionary path to developing new treatments for breast cancer,” Suhad Ali, PhD, the study’s senior author from The Research Institute of the McGill University Health Centre, said in a news release.
Triple negative breast cancer, named because it lacks receptors for estrogen, progesterone, and HER2, is the most aggressive type of breast cancer and notoriously difficult to treat.
“While prognosis and treatment options for breast cancer patients as a whole have improved in recent decades, this is not true for women who develop triple negative breast cancer – they still have limited options for targeted treatment strategies, often require invasive chemotherapy, and have a poor prognosis,” Ali said.
Despite lacking the three factors that distinguish triple negative breast cancer, the disease tends to behave differently in different people. The discovery of the prolactin receptor’s role explains at least some of the diversity.
When the prolactin receptor was present in a tumor, the cancer was less aggressive and the patient had a better chance of survival. Researchers also noted when treating animal breast cancer models with the hormone, that the receptor lowered the ability of cancer cells to divide and limited the tumor spread.
The findings suggest that screening for the prolactin receptor in breast cancer could be a valuable practice. Tumors expressing the receptor could possibly be treated with a combination of the hormone and a milder form of chemotherapy, or with the hormone alone.
Although previous studies suggested that prolactin may be protective against breast cancer, the role of the breastfeeding hormone in this cancer type is considered controversial.