It is not just your hormones that change at menopause, it seems that as women age the cells responsible for maintaining healthy breast tissue stop responding to their immediate surroundings, including mechanical cues that should prompt them to suppress nearby tumours.
These new findings are attributed to scientists from the US Department of Energy’s National Laboratory at Berkeley and the University of Bergen, Norway. Their work sheds light on how aging alters cellular and molecular functions, and how these changes contribute to the prevalence of breast cancer in older women.
Who is at risk?
The disease is most frequently diagnosed among women aged 55 to 64 according to the National Cancer Institute and of course if you have a family link through the maternal line you will be more susceptible.
Two years ago the same scientists found that as women age, multipotent progenitors accumulate in breast epithelial tissue. They didn’t know why these cells increase in numbers, but they believed their cellular microenvironment — or the matrix of tissue surrounding them — plays a role. To explore this idea, the scientists examined human mammary epithelial cell samples from pre and post-menopausal women.
They found that breast tissue from women less than 30 years old is extremely responsive to changes to their immediate surroundings. The tissue responded to any stiffness by producing a defence mechanism of tumor suppressants. This natural response to change was not however seen in tissue from women older than 55. Instead of responding to the stiffness by upping the production of tumor-suppressing cells, multipotent progenitors from older women produced equal amounts of luminal and tumor-suppressing cells. That’s bad for a couple of reasons. The majority of cancers diagnosed in older women are luminal, and more multipotent progenitors means more cells that can become cancerous.
They found that as women age, multipotent progenitors, which are the cells responsible for maintaining healthy homeostasis in breast tissue, no longer respond to their microenvironment like they do in younger women. Older tissue does not correctly perceive differentiation cues, such as the mechanical stiffness of their surroundings.
The scientists traced this failure to a breakdown in a cellular process. The process converts external mechanical cues, in this case the stiffness of the tissue outside of the cell membrane, into an internal molecular message that tells the cell nucleus what to do. In multipotent progenitors in women older than 55, the molecules that help deliver this message are inefficiently activated, and they believe this breakdown stems from changes in the way women’s genes are activated and silenced as they grow older.
How to reduce your risk
Hormone balance is key here, so dealing with oestrogen dominance and rebalancing with progesterone to oppose the excess oestrogen is the best place to start. Next are lifestyle changes, as at menopause the more weight you have, the more fat cells there are to produce oestrogen so again maintaining a healthy weight is essential to reduce your risk.
One study has shown that in a study of two groups of breast cancer survivors who were considered obese or overweight the group who received weight loss and exercise counselling after six months, women in the weight loss counselling group experienced an approximate 30% decrease in C-reactive protein (CRP) levels compared with the group who received no counselling.
CRP is a marker of chronic inflammation and higher CRP levels have been associated with a higher risk of breast cancer mortality. The women who lost at least 5% body weight experienced an approximate 22% decrease in insulin, 38% decrease in leptin, and 55% decrease in CRP, compared to significantly less biomarker improvement in women who lost less than 5% body weight.
Diet alone is not enough, exercise is also a key component as a similar story applies to exercise where participants were randomised into two groups — those who participated in twice-weekly strength training and 2.5 hr/wk of moderate-intensive aerobic exercise — and those who did no exercise (control group). After 12 months, the study found that the exercise group experienced an approximate 3% weight and body fat loss, and 6% decrease in CRP levels compared to increases in the control group.