No woman wants to get the news that she has breast cancer, especially if she’s just given birth. Unfortunately, a new study shows that women who develop breast cancer after pregnancy may be at a higher risk of dying of the disease compared to women without a recent pregnancy.
Breast Cancer after Pregnancy: Worse Prognosis?
Researchers looked at 2,752 breast cancer patients who were seen at the University of Western Australia. They found that women diagnosed with breast cancer after pregnancy (within a year of being pregnant) and who were under the age of forty-five had a 48% greater risk of dying of the disease than non-pregnant women. They also found that women diagnosed with breast cancer during pregnancy were at only a slightly higher risk of death (which was not considered to be significant) compared to non-pregnant women.
Why is Breast Cancer After Pregnancy More Deadly?
Breast cancer is a disease that’s influenced by hormone levels – especially levels of estrogen. Although having completed one or more pregnancies before the age of thirty lowers the risk of breast cancer, the higher levels of estrogen that are produced when a woman is pregnant increases the risk of getting the disease during the first ten years after the pregnancy is completed. And now, it seems that breast cancer after pregnancy (within a year) worsens the prognosis too.
Levels of three major hormones, estrogen, progesterone, and prolactin rise during pregnancy and each has it own effects on breast tissue. Studies show that prolactin, the hormone associated with milk production for breast feeding, causes growth of breast cancer cells and helps to maintain their survival. Although breast feeding lowers breast cancer risk in the long term, short term the risk may rise because of prolactin stimulation of the breast tissue. This could also play a role in the worse prognosis of women who get breast cancer after pregnancy.
Breast Cancer After Pregnancy: There’s Still More to Learn
The researchers in this study emphasize that there’s still much more that needs to be known about how pregnancy affects breast cancer and why the prognosis is worse when breast cancer is diagnosed after a pregnancy. Hopefully, further studies will provide answers that might be helpful for the treatment of all breast cancers.
American Journal of Epidemiology Vol. 153, No. 11 : 1079-1084
Science Daily website. “New Evidence Of Prolactin’s Possible Role In Breast Cancer Uncovered”.
Family Practice News. April 15, 2010. page 48.