Association of Breast Cancer Symptoms with Patients' Quality of Life and Depression; A Croatian Cross-Sectional Study.

Aim: To find out which symptoms are the most associated with a breast cancer patients' quality of life (QoL) and depression.

Subjects And Methods: We performed this cross-sectional study from February to April 2015 at the Department of Medical Oncology, University Hospital for Tumors, Zagreb University Hospital Center "Sestre milosrdnice", Zagreb, Croatia on the sample of 147 breast cancer patients. Primary outcomes were EORTC QLQ-C30 version 3.0 Global QoL scale and Beck Depression Inventory II.

Results: After the adjustment for other symptoms, sociodemographic and clinical variables, fatigue (β=-0.47, P<0.001), pain (β=-0.24, P=0.023), and appetite loss (β=-0.18, P=0.037) were statistically significantly correlated with QoL. Fatigue was the only symptom significantly associated with depression (β=0.39, P=0.006).

Conclusion: Fatigue, pain, appetite loss contributes the most to the overall breast cancer patients QoL. Although correlated, fatigue and pain contribution to lower QoL is independent from each other. Future studies should investigate whether there is an interaction between fatigue and pain changes over course of treatment. Fatigue and number of children are positively, while age and treatment in daily hospital are negatively associated with depression measured by BDI-II.