Women who receive chemotherapy or radiation therapy treatments for breast cancer are more likely to have high levels of DNA damage and reduced activity of an enzyme involved in chromosome healing than those who receive only surgery for breast cancer, according to the results of a study published in NPJ Breast Cancer.

Researchers assessed 94 women who were three to six years post-treatment for primary breast cancer. Those who had received chemotherapy and/or radiation therapy had elevated levels of DNA damage in blood cells and lower telomerase enzymatic activity compared to women who had surgery alone. The researchers also found that longer-term increases in DNA damage and reductions in telomerase activity coincided with higher levels of inflammation, which is another indicator of biologic aging. No differences were found in telomere length among any of the women, regardless of type of treatment received.

Late effects of cancer treatment are thought to be the result of accelerated biologic aging from those treatments. DNA damage accumulates in immune cells and prevents them from dividing, a key element of the aging process.

The authors called for additional research focused on understanding the biology of treatment effects on aging pathways, the findings of which could be used to develop strategies to prevent those changes in cancer survivors in the future.