Abstract PO1-12-11: How do chemotherapy and age affect physical performance in breast cancer patients over 12 months of treatment? Results from the UPBEAT Study (UPBEAT WF-97415)

Abstract

Abstract Introduction: Chemotherapy-associated functional decline is a concern for women with breast cancer. Objective: To assess effects of chemotherapy and age on objectively measured physical performance among women with breast cancer over time. Methods: Analyses utilized the multicenter, longitudinal Understanding and Predicting fatigue, cardiovascular decline, and events after BrEast cAncer sTudy (UPBEAT), a study conducted through the Wake Forest NCORP Research Base (5UG1CA189824). We examined physical performance at baseline and at 3 and 12 months and compared means across time by age group (< 65 years v. 65+ years at baseline) and by cancer/control group. For the latter variable, we had 3 groups of participants: 1) newly diagnosed breast cancer patients with Stage 1-3 breast cancer who received chemotherapy (CC; n= 201); 2) newly diagnosed breast cancer patients receiving no chemotherapy (CNC; n=57); and age-matched healthy controls (HC; n=145). The primary outcome was the Short Physical Performance Battery (SPPB) score (range 0-12, worst to best performance, including chair stands, gait speed, and balance testing). Effects of cancer/control group, age group, and time (treated categorically rather than ordinally) were estimated in a mixed model with a random subject effect and fixed effects of time (baseline, 3 month, 12 month) and cancer/control group. In the model we included all first-order interactions as well as the one second-order interaction between all three predictors. We also used linear contrasts to compare estimated means within groups. Analyses were conducted in SAS 9.4. A two-tailed alpha of 0.05 was used throughout to denote statistical significance. Results: Among 403 patients accrued through the Wake Forest Research Base of NCORP, 201 were in the CC group, and 18.9% of these were aged 65 and older; 57 were in the CNC group, and 33.3% were older; and 145 were in the HC group, and 15.9% were 65 or older. We observed a significant (p< 0.0001) main effect of older age group in our model: across all 3 groups, and all 3 time points, those who were 65 years of age or older had worse SPPB scores than those who were younger. Healthy controls tended to have better mean scores than the other 2 cancer/control groups, though the main effect of group did not achieve statistical significance (p=0.06). We observed no significant interaction terms; in other words, the effect of being older (in terms of association with worse SPPB scores) did not vary by time or group. Within the CC group, both the older and the younger groups declined significantly (p=0.04) in mean SPPB at 3 months compared to baseline, but by 12 months, the means had returned to their starting points. No other groups showed significant changes over time. Conclusions: Chemotherapy was associated with decline in SPPB score over the 12-month time period regardless of age. Older adults, regardless of chemotherapy status and time point, had lower SPPB scores. Citation Format: Shirley Bluethmann, Beverly Levine, Brianna Leitzelar, Katherine Ansley, Alexandra Thomas, Nancy Avis, Gregory Hundley, Heidi Klepin, Kathryn Weaver, Glenn Lesser. How do chemotherapy and age affect physical performance in breast cancer patients over 12 months of treatment? Results from the UPBEAT Study (UPBEAT WF-97415) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-12-11.