There is an intricate connection between breast cancer and pregnancy. In a study, researchers explain why women who become first-time mothers later in life have a higher long-term risk of breast cancer than those who become moms early.
Studies show that young first-time mothers, those who are below the age of 24 during their initial pregnancy, experience a substantially lower long-term risk of breast cancer (approximately 20-35%) compared to women who have not had kids.
However, as the age of first-time mothers goes up, the breast cancer risk also progressively increases, with a 5% spike in risk every five years.
“In recent decades, women have begun having children later because of societal changes and personal preferences. Previous research has found that this is associated with a heightened breast cancer risk,” Dr. Biancastella Cereser, a lead author of the study, said in the news release.
“Our own research delves into the genetic mysteries that govern this risk. We found that the human breast, like other organs, accumulates mutations with age, but also that pregnancy has an additional effect, meaning that older first-time mothers might have a higher chance of developing harmful changes in their breast cells compared to other women,” Cereser said.
In the latest study, published in the journal Nature Communications, researchers analyzed the cellular and genetic changes that happen to healthy breast cells as they turn cancerous. After sequencing 29 frozen healthy breast tissues from donors, the team found that with age, these healthy breast tissues accumulate mutations, at the rate of around 15 mutations every year. Although the majority of these mutations do not affect the genes and are not cancer-causing, with more time, there is a greater chance of having driver mutations associated with cancer.
“This might not be enough to cause cancer by itself. But, pregnancy could provide a ‘double whammy’, because it induces a rapid expansion of breast cells, in preparation for breastfeeding. If cells harboring driver mutations replicate and expand, they could have a competitive advantage over neighboring non-mutated cells, potentially leading to a runaway effect, and ultimately creating a cancerous tumor,” Cereser explained.
Published by Medicaldaily.com