Cancer-Specificity of Sex Differences and Sex-Specific Impact of Sociodemographic Characteristics in Cancer Patients' Health-Related Quality of Life: A Cross-Sectional Study

Background: Health-related quality of life (HRQoL) is a multi-dimensional concept commonly assessed in patient-centered research on the impact of cancer and its treatment. Apart from disease and treatment characteristics, HRQoL is also influenced by sociodemographic variables. However, detailed evaluations of the impact of sociodemographic variables on HRQoL are scarce. Therefore, our study aims to (1) examine whether the magnitude of sex differences in HRQoL differs between cancer patients and the general population and (2) investigate if there is a sex-specific association between sociodemographic characteristics and cancer patients' HRQoL scores. Methods: For this retrospective, cross-sectional study, we relied on two datasets, with one providing HRQoL data from Austrian cancer patients (N = 574) and another containing normative data from the Austrian general population (N = 1002). HRQoL was assessed using the EORTC QLQ-C30 questionnaire. Results: Sex differences in HRQoL were observed in both cancer patients and the general population, with the magnitude of observed sex differences varying between the two groups in two EORTC QLQ-C30 scales, that is, statistically significant differences were found for Nausea/Vomiting (p = 0.009) and Sleep Disturbances (p = 0.042). Analyzing sex differences in cancer patients with regard to in the association of sociodemographic variables with EORTC QLQ-C30 scales, we found the strength of certain associations to be sex-specific, including associations of living situation with physical (p = 0.001), role (p = 0.004), and social functioning (p = 0.011). Conclusion: Our findings indicate that most sex differences in cancer patients' HRQoL reflect sex differences that also occur in the general population and are therefore, not cancer-specific, which is essential for the interpretation of cancer patients' HRQoL data. Sex-specific differences may also be, in part, associated with the sex-specific impact of sociodemographic variables on cancer patients' HRQoL. Detailed analyses of HRQoL data, including reference data from the general population, may allow for a better understanding of sex-specific treatment needs.