Depressive and Post-Traumatic Stress Symptoms and Their Associations with Health-Related Quality of Life in Women with Breast Cancer: A Cross-Sectional Secondary Analysis

Background: Breast cancer (BC) significantly affects patients’ quality of life (QoL), not only through the physical burden of disease and its treatment but also through psychological mechanisms. The aim of this study was to investigate the associations between HRQoL, depressive symptoms, and post-traumatic stress symptoms in Greek women with BC, and to examine sociodemographic and clinical factors associated with depressive and post-traumatic stress symptom severity. Methods: This cross-sectional secondary analysis included 107 women with BC from a previously described cohort. Participants completed a structured demographic and clinical questionnaire, the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5), the Patient Health Questionnaire-9 (PHQ-9), and the EORTC Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30). Results: In total, 64.5% of participants had moderate to severe depressive symptoms, with a mean PHQ-9 score of 11.9. In exploratory adjusted analyses, mastectomy and an interval of 1–3 years since BC diagnosis were associated with higher PHQ-9 scores, whereas previous endocrine therapy alone was associated with lower PHQ-9 scores. Regarding post-traumatic stress symptoms, 51.4% of participants met all four PCL-5 DSM-5 symptom-cluster requirements for probable PTSD. Rural residence, mastectomy, and an interval of 1–3 years since BC diagnosis were independently associated with higher PCL-5 scores. Greater depressive symptom severity and probable PTSD status were both significantly associated with poorer HRQoL across multiple functional and symptom domains. Participants meeting the PCL-5 symptom-cluster criteria for probable PTSD also reported greater depressive symptom severity. Conclusions: Greek women with BC experienced a substantial burden of depressive and post-traumatic stress symptoms, which were closely interrelated and associated with poorer HRQoL. Exploratory multivariable analyses suggested associations between selected sociodemographic and clinical characteristics and psychological symptom severity; however, larger prospective studies are needed to confirm these findings. The findings support the relevance of psychological assessment as part of comprehensive BC care.