Impact of Illness Uncertainty on Quality of Life in Breast Cancer Patients: Mediating Role of Social Support

Background: Breast cancer remains a leading cause of morbidity and mortality among women globally, with psychological distress and diminished quality of life prevalent in resource-limited settings such as Pakistan. Limited research has addressed the role of illness uncertainty and the mediating impact of social support on quality of life in this population, underscoring a critical knowledge gap. Objective: This study aimed to examine the direct effect of illness uncertainty on quality of life and to evaluate the mediating role of social support among women diagnosed with breast cancer. Methods: A cross-sectional observational study was conducted among women with histologically confirmed breast cancer (n = 211) recruited from tertiary hospitals in Rawalpindi and Islamabad. Eligible participants were aged 20–50 years, receiving active treatment, with at least elementary education and fluency in Urdu or English. Standardized questionnaires—the Mishel Uncertainty in Illness Scale, FACT-B, and Multidimensional Scale of Perceived Social Support—were administered in a single session. Ethical approval was obtained from the Institutional Review Board, adhering to the Declaration of Helsinki. Data were analyzed using SPSS v21, employing descriptive statistics, Pearson correlation, multiple linear regression, and mediation analysis via the PROCESS macro. Results: Illness uncertainty significantly and negatively predicted quality of life (β = –0.29, p < .001), accounting for 8.4% of its variance. Social support partially mediated this association (indirect effect = 0.019, 95% CI: 0.003–0.041), with the full model explaining 17.2% of the variance in quality of life. Higher social support was associated with improved well-being despite persistent uncertainty. Conclusion: Addressing illness uncertainty and reinforcing social support are essential to optimizing quality of life in breast cancer care, advocating for integrated psychosocial interventions within oncology services in low-resource settings.