Depression and cancer-related fatigue in elderly colorectal cancer patients: A cross-sectional study with focus on the mediating role of chemotherapy-induced peripheral neuropathy and the moderating role of perceived social support

This study examines whether chemotherapy-induced peripheral neuropathy (CIPN) mediates the relationship between depression and cancer-related fatigue (CRF) and further investigates the moderating role of perceived social support (PSS) in this relationship among Chinese older adults with colorectal cancer (CRC). A total of 290 elderly Chinese patients with CRC undergoing chemotherapy were recruited. Structured questionnaires were administered to assess levels of depression, symptoms of CIPN, CRF, and PSS. Moderated mediation models were tested using the PROCESS macro (Models 4 and 8) in SPSS, controlling for relevant demographic and clinical covariates, to examine the hypothesized path relationships and interaction effects. After controlling for relevant covariates, CIPN was found to partially mediate the relationship between depression and CRF (indirect effect = 0.231), accounting for 38.44% of the total effect. Moreover, PSS significantly moderated the associations between depression with both CIPN (β = 0.101, P < .05) and CRF (β = 0.018, P < .05), such that higher levels of PSS strengthened these relationships. CIPN may be a potential pathway reflecting how emotional disturbances, particularly depression, are associated with CRF in elderly patients with CRC. The subjective experience of CIPN appears to be closely related to depressive symptoms. Contrary to the classical stress-buffering hypothesis, PSS did not exhibit a protective effect; rather, in certain cultural contexts, it may be linked to the physiological manifestations of negative emotions. These findings underscore the need for culturally sensitive and context-specific approaches to emotional intervention and social support in symptom management to optimize individualized care strategies for elderly CRC patients.