Abstract 5757: Breast cancer diagnosis and treatment associated with acceleration of biological aging over time in a racially diverse cohort of women
Authors: Kresovich Jacob K. , O'Brien Katie M. , Xu Zongli , Weinberg Clarice R. , Sandler Dale P. , Taylor Jack A. 
Published: April 2023

Abstract
Leukocyte DNA methylation (DNAm) at individual sites across the genome can be used to construct measures of biological age. Positive age acceleration—when biological age is older than chronological age—is associated with higher risk of age-associated diseases. Recent adjuvant therapy is reported to increase age acceleration, but the longer-term effects of a breast cancer diagnosis and treatment on age acceleration remain unknown. Here, we use blood samples collected at two timepoints to examine changes in age acceleration over time comparing women who did and did not develop breast cancer. Paired whole blood samples were drawn an average of 8 years apart (range: 5-11 years) in a sample of non-Hispanic White and Black (Hispanic and non-Hispanic) women. DNAm was profiled using Infinium MethylationEPIC BeadChips. Approximately half the women were diagnosed and treated for breast cancer between blood draws (cases; n= 190, baseline mean age= 57) whereas the other half remained breast cancer-free (controls; n= 227, baseline mean age= 56). Longitudinal changes in three age acceleration metrics were compared to determine whether an intervening breast cancer diagnosis and treatment was associated with trajectories in biological aging. On average, the cases were diagnosed with breast cancer 3.5 years after the initial blood draw and 4 years before the second blood draw. Among the cases, 36% were treated with chemotherapy, 65% with radiation therapy, and 70% with hormonal therapies; 45% of the cases received two types of therapy, and 13% received all three. Compared to women who remained cancer-free, women diagnosed and treated for breast cancer had increases in age acceleration over time as measured by PhenoAgeAccel (adjusted standardized mean difference (β)= 0.13, 95% CI: 0.00, 0.26), GrimAgeAccel (β= 0.13, 95% CI: 0.03, 0.24), and DunedinPACE (β= 0.35, 95% CI: 0.23, 0.48). The associations did not vary by timing of diagnosis between the blood draws or race; however, women diagnosed with estrogen receptor (ER) negative tumors appeared to experience faster increases in age acceleration than women diagnosed with ER positive tumors (GrimAgeAccel; ER negative β= 0.27, 95% CI: 0.07, 0.47; ER positive β= 0.10, 95% CI: -0.01, 0.21; P-interaction= 0.14). To investigate the impact of different types of breast cancer therapies, associations were examined using a case-only design. In models that simultaneously included chemotherapy, radiation therapy and hormone therapy, radiation therapy had the strongest associations with accelerated biological aging as measured by PhenoAgeAccel (β= 0.38, 95% CI: 0.18, 0.58), GrimAgeAccel (β= 0.27, 95% CI: 0.09, 0.45), and DunedinPACE (β= 0.25, 95% CI: 0.03, 0.47). We find that years after the initial diagnosis, breast cancer survivors have significantly accelerated biological aging; treatment modalities may differentially influence these rates.
Citation Format: Jacob K. Kresovich, Katie M. O'Brien, Zongli Xu, Clarice R. Weinberg, Dale P. Sandler, Jack A. Taylor. Breast cancer diagnosis and treatment associated with acceleration of biological aging over time in a racially diverse cohort of women. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5757.