Background
Postmenopausal women with cancer experience an accelerated physical dysfunction beyond that expected through aging alone due to cancer and its treatments. The aim of this study is to determine whether declines in physical function after cancer diagnosis are associated with all-cause mortality and cancer-specific mortality.
Methods
This prospective cohort study included 8,068 postmenopausal women enrolled in the Women’s Health Initiative (WHI) who were diagnosed with cancer and had physical function assessed within 1-year of cancer diagnosis. Self-reported physical function was measured using the 10-item physical function subscale of the RAND 36-Item Health Survey. Cause of death was determined by medical record review with central adjudication and linkage to the National Death Index. Death was adjudicated through February 2022.
Results
Over a median follow-up of 7.7 years from cancer diagnosis 3,316 (41.1%) women died. Our results showed that for every 10% decline in the physical function score after cancer diagnosis, all-cause mortality and cancer-specific mortality were significantly reduced by 12% (HR, 0.88; 95% CI, 0.87 to 0.89) and (HR, 0.88; 95%CI, 0.86 to 0.91), respectively. Further categorical analyses showed a significant dose-response relationship between post-diagnosis physical function categories and mortality outcomes (trend test P < .001), where the median survival time for women in the lowest physical function quartile was 9.1 (8.6, 10.6) years compared to 18.4 (15.8, 22.0) years for women in the highest physical function quartile.
Conclusion
Postmenopausal women with low physical function after cancer diagnosis may be at higher risk of mortality from all causes and cancer-related mortality.