The Association Between Social Support and Psychosomatic Status in Cancer Patients During Mid-Course Radiotherapy: The Chain Mediating Roles of Psychological Capital and Coping Styles

Background: Cancer patients undergoing mid-course radiotherapy frequently experience psychosomatic distress, yet the psychosocial correlates and indirect pathways associated with this phenomenon remain insufficiently understood. Objective: To examine the direct and indirect associations between social support and psychosomatic status through psychological capital and coping styles in cancer patients undergoing mid-course radiotherapy. Methods: A cross-sectional study was conducted among 327 cancer patients recruited from the radiotherapy center of a tertiary-level general hospital between August 2025 and February 2026. Questionnaires were administered during the mid-course of radiotherapy, defined as the point at which the cumulative radiation dose reached 50% of the planned total dose. The Multidimensional Scale of Perceived Social Support (MSPSS), the Positive Psychological Capital Questionnaire (PPQ), the Cancer Coping Modes Questionnaire (CCMQ), and the Psychosomatic Status Scale for Cancer Patients (PSSCP) were utilized for assessment. Higher MSPSS, PPQ, and CCMQ scores indicate higher perceived social support, higher psychological capital, and more frequent use of the corresponding coping style, respectively, whereas higher PSSCP scores indicate poorer psychosomatic status. Results: (1) Social support, psychological capital, and positive coping scores were significantly negatively correlated with PSSCP scores, whereas negative coping scores were significantly positively correlated with PSSCP scores. (2) Structural equation modeling showed that social support was directly associated with psychosomatic status and indirectly associated with psychosomatic status through the independent and chain mediating roles of psychological capital and coping styles. Conclusions: Among cancer patients undergoing mid-course radiotherapy, higher levels of social support were associated with better psychosomatic status. This association was partially mediated by psychological capital and coping styles, both independently and sequentially. Given the cross-sectional design, these mediation findings should be interpreted as association-based. The findings highlight the potential importance of integrating social support enhancement with interventions targeting psychological resources and coping behaviors to support psychosomatic well-being during radiotherapy.