Deficit Accumulation Frailty Trajectories of Older Breast Cancer Survivors and Non-Cancer Controls: The Thinking and Living with Cancer Study.

BACKGROUND We evaluated deficit accumulation and how deficits affected cognition and physical activity among breast cancer survivors and non-cancer controls. METHODS Newly diagnosed non-metastatic survivors (n = 353) and matched controls (n = 355) ages 60-98 without neurological impairments were assessed pre-systemic therapy/enrollment from August 2010-December 2016 and followed for 36-months. Scores on a 42-item index were analyzed in growth-mixture models to determine deficit accumulation trajectories separately and combined for survivors and controls. Multilevel models tested associations between trajectory and cognition (FACT-Cog and neuropsychological tests) and physical activity (IPAQ-SF) for survivors and controls. RESULTS Deficit accumulation scores were in the robust range, but survivors had higher scores (95% confidence intervals) than controls at 36-months (0.18 [0.16 to 0.19] vs. 0.16 [0.14 to 0.17] at 36 months, p=.001) and averages included diverse deficit trajectories. Survivors that were robust but became frailer (8.8%) had similar baseline characteristics to those remaining robust (76.2%) but experienced a 9.6-point decline self-reported cognition (decline of 9.6 vs. 3.2 points, p=.04) and a 769 MET-minutes/week decline in physical activity (p<.001). Survivors that started and remained pre-frail (15.0%) had self-reported and objective cognitive problems. At baseline, frail controls (9.5%) differed from robust controls (83.7%) on deficits and self-reported cognition (p<.0001). Within combined trajectories, frail survivors had more sleep disturbances than frail controls (48.6% [SD = 17.4%] vs. 25.0% [SD = 8.2%], p=.05). CONCLUSIONS Most survivors and controls remained robust and there were similar proportions on a frail trajectory. However, there were differences in deficit patterns between survivors and controls. Survivor deficit accumulation trajectory was associated with patient-reported outcomes. Additional research is needed to understand how breast cancer and its treatments affect deficit accumulation.