Correlates of existential well-being and their association with health-related quality of life in breast cancer survivors compared with the general population.

The aim was to evaluate the correlates of existential well-being (EWB) and investigate the relationship between EWB and health-related quality of life (HRQOL) according to the McGill Quality of Life Questionnaire (MQOL) in breast cancer survivors (BCS) and in the general population. BCS (N = 1,933) recruited from five large hospitals completed a mailed survey, which included the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (QLQ-C30), Quality of Life Questionnaire Breast Cancer Module (QLQ-BR23) and the MQOL. Reference data were derived from a representative sample of the Korean adult population composed of 500 women selected by a nationwide random route technique. Multiple logistic regression analysis showed that members of the general population with a lower educational status were more likely to report poor EWB. However, among BCS, correlates that were associated with poor EWB included lower monthly income, lower educational status, unemployment and comorbidities. Almost all factors listed on the HRQOL questionnaire were correlated with EWB in BCS as well as in the general population (P < 0.001). Factors listed on the QLQ-C30 that were correlated to a clinically meaningful extent with EWB in the general population included physical functioning, nausea and vomiting, and appetite loss, whereas among BCS, insomnia and distress over hair loss were meaningfully correlated with EWB. Compared with general population, BCS showed different EWB correlates and distinct associations with HRQOL findings. Our data suggest that socio-economic status and comorbidities influence on their EWB.