Perceived social support as a mediator of the relationship between fear of progression and post-traumatic growth in lung cancer patients undergoing chemotherapy: a structural equation model analysis.

BACKGROUND: Post-traumatic growth (PTG), as a positive psychological adaptation mechanism, can significantly enhance patients' psychological resilience and promote positive psychological transformation. However, among lung cancer patients undergoing chemotherapy, fear of progression (FoP) is associated with substantial psychological distress and lower levels of positive adaptation. Research on the association between FoP and PTG in this population remains limited. OBJECTIVE: To investigate the association between FoP and PTG among lung cancer patients undergoing chemotherapy, and to examine whether perceived social support (PSS) statistically mediated this association. METHODS: A cross-sectional design was conducted among lung cancer patients undergoing chemotherapy at a Grade A tertiary hospital in Deyang City from March to July 2025. Data collection involved the use of a general information questionnaire, the Fear of Progression Questionnaire-Short Form (FoP-Q-SF), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Post-Traumatic Growth Inventory (PTGI). A total of 225 questionnaires were distributed, yielding 216 valid responses. Statistical analyses were performed using R software (version 4.5.2). The psych package was used for descriptive statistics, Pearson correlation analysis, and Harman's single-factor test to assess common method bias. Structural equation modelling with maximum likelihood estimation was performed using the lavaan package. The indirect effect of PSS was tested using percentile bootstrap confidence intervals (5,000 resamples). RESULTS: The mean PTG score was 41.26 ± 16.41. Pearson correlation analysis revealed a negative association between FoP and PTG (r = -0.454, P < 0.01), a negative association between FoP and PSS (r = -0.335, P < 0.01), and a positive association between PSS and PTG (r = 0.387, P < 0.01). Mediation analysis indicated that PSS accounted for a significant indirect effect in the association between FoP and PTG, representing 19.4% of the total effect. CONCLUSION: An indirect association between FoP and PTG via PSS was identified in this study. These findings suggest that social support and reduced fear of disease progression may be associated with greater psychological growth among lung cancer patients undergoing chemotherapy. Social support may warrant consideration as a potential intervention target for fostering positive psychological adaptation.