Razi University

 Cancer is one of the leading causes of mortality from non-communicable diseases worldwide, and despite significant advances in diagnosis and treatment, it remains a major challenge for health systems. The present study aimed to determine the mediating role of cognitive flexibility in the relationship between health literacy and intolerance of uncertainty with fear of cancer recurrence (FCR) among cancer survivors referring to hospitals in Kermanshah. In terms of purpose, this study was applied, and in terms of data nature and collection method, it was descriptive-correlational using a structural equation modeling (SEM) approach. The statistical population consisted of cancer survivors (at least six months since completing any cancer-related treatment, excluding medication) in Kermanshah in 1405 (2026). Sample size was determined using Stevens' proposed rule, and considering possible sample attrition or incomplete questionnaires, the final sample size was set at 275 participants. Data were collected using a demographic information form, the Health Literacy Questionnaire by Montazeri et al. (2015), the Intolerance of Uncertainty Scale by McLean (2009), the Fear of Cancer Recurrence Inventory by Simard and Savard (2009), and the Cognitive Flexibility Inventory by Dennis et al. (2010). Data were analyzed using SPSS version 24 and Amos version 24. The results showed that health literacy (? = -0.156, p = 0.037) was a significant negative predictor of fear of cancer recurrence. Intolerance of uncertainty (? = 0.795, p = 0.001) was a significant positive predictor of fear of cancer recurrence. Cognitive flexibility (? = -0.460, p = 0.001) was also a significant predictor of fear of cancer recurrence among the studied variables. Health literacy (? = 0.483, p = 0.001) was a significant positive predictor of cognitive flexibility, whereas intolerance of uncertainty (? = -0.038, p = 0.616) was not a significant predictor of cognitive flexibility. Bootstrap analysis revealed that the indirect effect of health literacy on fear of cancer recurrence through cognitive flexibility was -0.221 (95% CI: -0.308 to -0.134, p = 0.001), and the indirect effect of intolerance of uncertainty on fear of cancer recurrence through cognitive flexibility was 0.058 (95% CI: 0.042 to 0.283, p = 0.016). Overall, all fit indices fell within acceptable and even favorable ranges, indicating that the final research model achieved a good fit. In conclusion, the findings of the present study demonstrated that cognitive flexibility functions as a mechanism through which health literacy and intolerance of uncertainty exert their effects on fear of cancer recurrence. These results underscore the necessity of designing and implementing educational and therapeutic interventions focused on strengthening cognitive flexibility and enhancing health literacy as an effective strategy for reducing fear of cancer recurrence among cancer survivors.