Triple negative breast cancer (TNBC) refers to a tumor that is estrogen receptor-negative,
progesterone receptor-negative and HER2-negative. It is the most
aggressive type of breast cancer and it is very difficult to treat.
A study conducted at the Research Institute of the McGill University
Health Center (RI-MUHC) suggests screening breast cancer patients for
the prolactin receptor could improve the prognosis for patient and may
help them avoid unnecessary and invasive treatments.
‘Screening breast cancer patients for the prolactin receptor could improve the prognosis for patient and may help them avoid unnecessary and invasive treatments.’
Using a database of
580 women with TNBC, the researchers
found that survival was prolonged in patients who expressed the
prolactin receptor and that prolactin hormone was able to reduce the
aggressive behavior of cancerous cells. It does so by decreasing their
ability to divide and form new tumors. The research was published in the
journal Scientific Reports
Dr. Ali, a researcher from the Cancer Research Program at the
RI-MUHC and lead author of the study, said, "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 TNBC - they still have
limited options for targeted treatment strategies, often require
invasive chemotherapy and have a poor prognosis."
The reason for this is that TNBC cancers are diverse and do not
behave in the same manner in all patients, something that researchers
have not fully understood. However, Dr. Ali's team may have found the
key to unlock this mystery. They discovered that women with tumors that
express the prolactin receptor had a less aggressive breast cancer and a
far better prognosis. Furthermore, in a preclinical animal model, they
determined that if the prolactin receptor was not present, the tumor
cells were not just more aggressive, but also proliferative and invasive
compared with the ones that express the prolactin receptor.
The results suggest that screening for the prolactin receptor could
indicate which patients might benefit from prolactin treatment as a
single agent, or in combination with less aggressive chemotherapy,"
explains Dr. Ali. "We think this could be a revolutionary path to
developing new treatments for breast cancer.".
Women's health and prolactin
The role of prolactin in breast cancer is not fully characterized
and still controversial. Better understanding of its role in cancer
could have directly impact in doctor advice to patients with high risk
of developing breast cancer to practice breastfeeding as a protective
measure. These findings are consistent with past studies suggesting that
prolactin has a suppressing effect on breast cancer. Dr. Ali states
"our research supports that breastfeeding is not only beneficial for
infants but also for the mothers. Since breastfeeding is a natural way
to produce prolactin in high levels, breastfeeding would actually reduce
a woman's risk of developing breast cancer".