Purpose: Cultural differences are hypothesized to influence patients' Quality of Life (QoL) reports. However, there is a lack of empirical cross-cultural studies comparing QoL of patients with cancer. This study aims to compare QoL of women with breast cancer in the Netherlands and Japan, and to investigate the association of QoL with sociodemographic, clinical, and psychological variables (illness perceptions).
Methods: Dutch (n = 116) and Japanese (n = 148) women with early breast cancer undergoing chemotherapy completed the EORTC QLQ-C30 and Brief Illness Perception Questionnaire immediately before their second cycle of chemotherapy.
Results: Dutch women reported poorer Physical, Role, Emotional, and Cognitive functioning than Japanese women. Additionally, illness perceptions were significantly different in Japan and the Netherlands, but these did not vary across treatment type. In Japan, QoL of women receiving AC-chemotherapy was better than that of women receiving FEC-chemotherapy, whereas in the Netherlands, QoL did not vary as a function of chemotherapy. Illness perceptions about symptom severity, adverse consequences, and emotional representations were negatively related to most domains of patients' QoL in both countries. Adding illness perceptions as covariates to the ANOVA analyses rendered the effects of country and treatment type on QoL non-significant.
Conclusions: Comparing Dutch and Japanese women with early breast cancer revealed important differences in treatment modalities and illness perceptions which both appear to influence QoL. Perceptions about cancer have been found to vary across cultures, and our study suggests that these perceptions should be considered when performing cross-cultural studies focusing on patient-reported outcomes.
Keywords: Breast cancer; Brief Illness Perception Questionnaire; Chemotherapy; Cross-cultural comparison; EORTC QLQ-C30; Illness perceptions.