Functional status declines among cancer survivors: trajectory and contributing factors

Objective: This study aimed to quantify functional status (FS) trajectories pre- and post-diagnosis of cancer, FS trajectories among cancer-free individuals, and factors affecting FS.

Materials and methods: Self-reported FS, scored from 0 (worst) to 100 (best), of Atherosclerosis Risk in Communities (ARIC) Study cohort participants diagnosed with incident cancer (lung (N=303), breast (N=374), prostate (N=529), colorectal (N=228)), and cancer-free participants (N=11,155) over 15 years was examined. FS was evaluated in two ways: 1) until death or follow-up year 15 (Model 1) and 2) same as survivorship model except that a FS value of zero was used for assessments after death to follow-up year 15 (Model 2). Mean FS at discrete time points were used to generate FS trajectories. Differences in repeated measures of FS were assessed using linear growth models.

Results: Within one year after diagnosis, FS scores declined compared to the cancer-free group, except for prostate cancer. FS continued to decline beyond one year after lung or colorectal cancer diagnosis. FS was lower in all cancer groups, except prostate, compared to the cancer-free group (Model 1: lung -4.76, breast -2.28, colorectal -2.55; Model 2: lung -2.36, breast -2.46, colorectal -2.31). Predictors of decreased FS score independent of cancer diagnosis included low education, comorbidities, obesity, smoking, lack of health insurance, and age.

Conclusion: FS in all incident cancer groups declined during the first year post-diagnosis, which could be due to intensive treatments. Targeting factors related to FS declines could improve health outcomes for patients with cancer.