Genetic Differences May Link to Breast Cancer Risk From Low-dose Radiation

The scientists, led by Andy Wyrobek of Berkeley Lab’s Life Sciences Division found genes in mice that may have application to identify a woman’s susceptibility or resistance to breast cancer after exposure to low-dose ionizing radiation, such as the levels used in full-body CT scans and radiotherapy.

Breast cancer patients with gene expression profiles like the cancer-resistant mice (before radiation exposure) were more likely to survive eight years after diagnosis. Women with gene expression profiles like the cancer-sensitive mice were less likely to survive after eight years.

Based on this, the scientists believe the cellular and tissue mechanisms that control mice’s risk of mammary gland cancer from low-dose radiation are similar to the mechanisms that affect a woman’s chance of surviving breast cancer.


They studied newly diagnosed women before they received radiation or chemical therapies. Women with gene expression levels like those of radiation-sensitive mice were less likely to survive after eight years. In contrast, women with expression levels like those of the resistant strain were more likely to survive the eight-year duration of the follow-up.

These differences again carried over to people. Breast cancer patients whose cell division and renewal genes were up-regulated like the cancer-sensitive mice didn’t survive as long as patients in which the same genes were suppressed.

Source: Drug Discovery & Development, Oct., 2012