Chemotherapy for Breast Cancer and Aging

 woman white with wrinkles

What You Need to Know: Adjuvant chemotherapy for breast cancer is gerontogenic, defined as accelerating the pace of physiologic aging, a new study reported.

Background: Loss of organ function, characterized by an increase in cellular senescence, is one physiological part of aging. Markers of cellular senescence have been identified as leukocyte telomere length, expression of senescence-associated cytokines including interleukin-6, and expression of p16INK4a, and ARF in peripheral blood T lymphocytes (PBTLs).

The authors previously showed p16INK4a is a marker of accelerated molecular age in PBTLs associated with smoking, physical inactivity, and chronic human immunodeficiency virus infection. To date, reports have not explored how long-term effect of cytotoxic chemotherapy given with curative intent affects molecular aging.

The Study: Hanna K. Sanoff, MD, Norman E. Sharpless, MD, and Hyman B. Muss, MD, of the Lineberger Comprehensive Cancer Center in Chapel Hill, North Carolina, and their colleagues prospectively collected blood and clinical data from 33 women with stage I-III breast cancer before, immediately after, 3 months after, and 12 months after anthracycline-based chemotherapy. Blood was analyzed for markers of cellular senescence.

The Evidence: They observed increased expression of the senescence markers p16INK4a and ARF in PBLTs immediately after chemotherapy, and these remained elevated for at least 1 year after treatment. In an independent cohort of 176 breast cancer survivors, prior chemotherapy was associated with a persistent increase in p16INK4a at an average of 3.4 years after treatment. These results suggest the age-promoting effects of chemotherapy last for several years after treatment and may be permanent.

The authors concluded, “We have shown that cytotoxic chemotherapy potently induces the expression of markers of cellular senescence in the hematologic compartment in vivo, comparable with the effects of 10 to 15 years of chronologic aging in independent cohorts of healthy donors.” Further studies are underway.

I’m Dr. Michael Hunter, and I do wonder how much of this aging can be “undone” with physical activity such as exercise.

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

Available now: Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Both can be found at the Apple Ibooks store. Coming Soon for iPad: Understand Breast Cancer in 60 Minutes; Understand Colon Cancer in 60 Minute; Understand Colon Cancer in 60 Minutes; Understand Brain Glioma in 60 Minutes. Thank you.

Reference: Journal of the National Cancer Institute (2014; doi:10.1093/jnci/dju057).

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