Exploring the relationship among dispositional optimism, health-related quality of life, and CIPN severity among colorectal cancer patients with chronic peripheral neuropathy

PURPOSE: Chemotherapy-induced peripheral neuropathy ((CI)PN) becomes chronic in 30% of cancer patients. Knowledge of predictors of chronic (CI)PN and related impairments in health-related quality of life (HRQoL) is lacking. We examined the role of optimism in chronic (CI)PN severity and associated HRQoL in colorectal cancer (CRC) patients up to two years after diagnosis. METHODS: CRC patients from a prospective cohort study participated, with sensory peripheral neuropathy (SPN) 1 year after diagnosis (n = 142). Multivariable regression analyses examined the cross-sectional association between optimism (measured by the LOT-R) and SPN severity/HRQoL (measured by the EORTC QLQ-CIPN20 and QLQ-C30), as well as the prospective association in a subsample that completed measures 2 years after diagnosis and still experienced SPN (n = 86). RESULTS: At 1-year follow-up, higher optimism was associated with better global HRQoL, and better physical, role, emotional, cognitive, and social functioning (all p < .01). Optimism at year one was also prospectively associated with better global HRQoL (p < .05), and emotional and cognitive functioning at 2-year follow-up (both p < .01). Optimism was not related to self-reported SPN severity. Significant associations were retained when controlling for demographic/clinical variables, and became non-significant after controlling for depressive and anxiety symptoms. CONCLUSIONS: Optimism and depressive and anxiety symptoms are associated with HRQoL in CRC patients with chronic (CI)PN. Future research may illuminate the mechanisms that these factors share, like the use of (non)adaptive coping styles such as avoidance and acceptance that may inform the design of targeted interventions to help patients to adapt to chronic (CI)PN.