Chemotherapy Accelerates Molecular Aging

Oncologists from the University of North Carolina (UNC) have directly measured the impact of chemotherapy treatment on biological aging. Hanna Sanoff, MD, MPH, assistant professor with the UNC School of Medicine and member of UNC Lineberger Comprehensive Cancer Center, and colleagues measured the level of p16, a protein that causes cellular aging, in the blood of 33 women (aged >50) who had undergone chemotherapy for curable breast cancer. Samples were taken for analysis of molecular age from patients before chemotherapy, immediately following chemotherapy, and a year after therapy finished. The results showed that curative chemotherapy caused an increase in molecular age that was equivalent to 15-years of chronological aging. The authors believe that the p16 test could be used to evaluate how chemotherapy will affect a patient's long-term health and survival, as well as being a predictive biomarker for the long-term toxicity of chemotherapy. "Our theory is that if you have an advanced molecular age to begin with, it will be harder for you to tolerate chemotherapy," said Dr Sanoff. "We believe a high level of p16 before treatment could mean that a patient will have a harder time making new blood cells after each chemotherapy treatment, and therefore be at greater risk for anemia and infection during chemotherapy." Study-co author Dr Hyman Muss, director of UNC Lineberger’s Geriatric Oncology Program concluded: “While these findings are highly provocative, we have much more to study and will have to verify in future trials how these changes in molecular aging affect long-term survival. Adjuvant chemotherapy has dramatically improved breast cancer survival and pending further data, the results of our study should not affect adjuvant chemotherapy decisions."