Positive psychological capital and social support mediate the association between perceived stress and fear of disease progression in postoperative lung cancer patients

Fear of disease progression (FoP) is a major unmet psychosocial need among patients with lung cancer following surgery. Although perceived stress is associated with FoP, the underlying psychosocial mechanisms remain unclear. This study aimed to examine the mediating roles of positive psychological capital and social support in the association between perceived stress and FoP among postoperative patients with lung cancer. A cross-sectional survey was conducted among 284 patients with lung cancer within one week after surgery at a tertiary cancer hospital in Zhejiang Province, China. Participants completed a general information questionnaire, the short form of the FoP Questionnaire (FoP-Q-SF), the Chinese Perceived Stress Scale (CPSS), the Universal Positive Psychological Capital Questionnaire, and the Social Support Rating Scale (SSRS). Data were analyzed using the bruceR package in R, corresponding to PROCESS Model 6. Positive psychological capital, social support, perceived stress, and FoP were all directly and significantly correlated. Mediation analysis showed three statistically significant indirect pathways linking perceived stress to FoP. First, positive psychological capital exerted a partial mediating effect (indirect effect = 0.046, Bootstrap 95% CI: 0.011–0.091), accounting for 11.9% of the total effect. Second, social support partially mediated the association (indirect effect = 0.038, Bootstrap 95% CI: 0.010–0.077), contributing 9.8% of the total effect. Finally, positive psychological capital and social support jointly exerted a chain mediating effect (indirect effect = 0.008, Bootstrap 95% CI: 0.001–0.019), accounting for 2.1% of the total effect. This study highlights the mediating roles of positive psychological capital and social support in the association between perceived stress and FoP among postoperative lung cancer patients. These findings suggest that perceived stress, positive psychological capital, and social support may represent relevant psychosocial factors associated with FoP.