Aging reshapes breast tissue creating environment favorable for cancer

In In The News by Barbara Jacoby

Source: University of Cambridge

From: news-medical.net

Scientists have created the most detailed map to date, comprised of over 3 million cells, showing how breast tissue changes as women age – including dramatic changes during menopause.

The map reveals how, as women age, the number of cells in their breast tissue decreases, and these in turn proliferate less, and the structure of breast tissue changes. This creates a ‘micro-environment’ in which cancer cells can thrive.

Details of the study, led by scientists at the Universities of Cambridge and British Columbia, are published today in Nature Aging.

Breast cancer is the most common form of cancer in women. It accounts for 15% of all new cancer cases, with four out of five cases occurring in women over 50. As many as one in seven women will develop breast cancer in their lifetime.

The team used advanced imagining techniques to analyse breast tissue from more than 500 women aged 15 to 86 years old. The tissue included biopsies taken from women for non-cancer-related reasons.

Combining these images with details of the hormone receptors and immune cells present, as well as the tissue architecture, the researchers were able to map how breast tissue changes over time in unprecedented detail. Their findings point to reasons why breast cancer risk increases with age and why tumours in younger women differ biologically.

Gupta added: “Our map revealed that as women age, their breast tissue goes through major changes, with the most dramatic changes occurring at menopause. There are changes, too, during their twenties, possibly linked to pregnancy and childbirth, but these are far less pronounced.”

The map revealed that all types of cells become fewer in number and divide far less often. Milk-producing structures known as lobules shrink or disappear, while the ducts that that carry milk become relatively more common, with the supporting layer around them becoming thicker. Fat cells increase while blood vessels decrease.