Somatic symptoms in cancer patients trajectory over 12 months and impact on functional status and disability.

ABSTRACT

PURPOSE: Cross-sectional studies have established the prevalence and functional impairment of somatic symptoms in cancer patients. The purpose of this study was to determine the trajectory and adverse consequences of such symptoms over time. METHODS: Secondary analysis of longitudinal data from 405 cancer patients enrolled in a telecare management trial for pain and/or depression. Somatic symptom burden was measured with a 22-item scale at baseline, 1, 3, 6, and 12 months. Outcomes included the SF-12 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, the Sheehan Disability Scale (SDS) score, and self-reported total disability days. Mixed methods repeated measures analyses were conducted to determine whether antecedent change in somatic symptom burden predicted functional status and disability. RESULTS: Symptoms were highly prevalent at baseline, with 15 of the 22 symptoms endorsed by more than half of the patients. A rather constant cross-sectional prevalence over 12 months at the group level belied a quite different trajectory at the patient level where the median persistence, resolution, and incidence rates for 14 of the most common symptoms were 39%, 37%, and 24%, respectively. A clinically significant (i.e., five points) reduction in somatic symptom burden predicted improvement in PCS, MCS, and SDS (all P < 0.001), as well as a lower likelihood of ≥14 disability days in the past 4 weeks (odds ratio, 0.84; 95% CI, 0.74 to 0.95). CONCLUSIONS: Somatic symptoms remain burdensome in cancer patients over 12 months and symptom improvement predicts significantly better functional status and less disability.