Cancer Treatment Increases Biological Age

The established non-surgical forms of cancer treatment, chemotherapy and radiotherapy, induce cellular senescence via stress and damage to cells. The target for these harmful effects is the cancer, but other cells are also inevitably stressed to the point of entering a senescent state. An increased burden of senescent cells in tissues throughout the body is a feature of aging. These cells directly contribute to dysfunction of tissues and organs via secreted signals, the senescence-associated secretory phenotype (SASP). When maintained over the long term, the SASP contributes to the onset and progression of age-related conditions. To the extent that a person suffers an increase in the burden of senescent cells, he or she becomes biologically older.

In this context, it is well known that cancer survivors exhibit a lower life expectancy and increased risk of age-related disease. It is presently thought that senescent cells are likely the primary cause of this outcome. In the near future, we might expect to see that cancer treatments are followed by senolytic therapies to clear the excess of senescent cells produced the therapy. Given sufficiently efficient senolytics, this approach will likely eliminate the lasting consequences of chemotherapy and radiotherapy.

Women treated for breast cancer may age faster than cancer-free women

Women diagnosed and treated for breast cancer have increased biological aging compared to women who remain free of breast cancer, according to a new study. Among women diagnosed with breast cancer, the association with faster biological aging was most pronounced for those who received radiation therapy, while surgery showed no association with biological aging. This finding suggests that developing cancer is not what increases the aging effect.

Biological age reflects a person's cell and tissue health, and it differs from chronological age. To measure biological age, the researchers studied 417 women who had blood samples collected at two time points about eight years apart. About half of the women studied were selected because they had developed breast cancer during that time span. The participants are enrolled in the Sister Study, a research effort that seeks to identify environmental risk factors for breast cancer risk and other health conditions, led by the National Institute of Environmental Health Sciences (NIEHS), part of NIH.

The researchers used three different established "methylation clocks" to determine if there were changes in a women's biological age between the two time points. The clocks measure naturally occurring, chemical modifications to a person's DNA, known as methylation changes. Small variations in methylation patterns can help determine a person's risk of developing an age-related disease. Women diagnosed with breast cancer had faster aging rates by all three clocks, with no significant racial differences, when compared to women who did not develop breast cancer.

Next the scientists examined whether biological age was associated with specific treatment regimens, such as surgery, chemotherapy, radiation therapy, and endocrine therapy. Among women with breast cancer, aging rates varied by treatment type. "Radiation is a valuable treatment option for breast cancer, and we don't yet know why it was most strongly associated with biological age. This finding supports efforts to minimize radiation exposures when possible and to find ways to mitigate adverse health effects among the approximately 4 million breast cancer survivors living in the United States."


Given that some of the cancerous cells, which become senescent, exit their senescent state and become cancerous again, senolytic therapy following chemo or radiation should increase the efficacy of those treatments as well, correct?

Posted by: Matthew at July 27th, 2023 1:31 PM
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