Predictors of quality of life in newly diagnosed melanoma and breast cancer patients

Background: Quality of life (QoL) is a multidimensional construct, and several psychosocial and medical factors can predict a patient's QoL. We investigated the impact of factors in the psychological stress processes on QoL 3 months after diagnosis of melanoma or breast cancer. Patients and methods: In consecutive melanoma and breast cancer patients with localized disease, cancer-specific social support, coping with cancer, personality trait anger expression, non-cancer stress, sociodemographic variables, cancer and treatment variables, and QoL (evaluated as self-reported psychological and physical symptoms, self-perceived QoL, and depression) were assessed with validated quantitative questionnaires. The associations between QoL and the other factors were investigated with multivariate methods. Results: Only a few factors differed between melanoma and breast cancer, in terms of treatment modalities and gender. The amount of received social support was higher among breast cancer patients. The predicting power of psychological stress factors on all the QoL measures was strong, but differed between the treatment groups (surgery only versus adjuvant treatment). Psychosocial factors were the strongest predictors of QoL, not cancer type or treatment. Behavioral Escape-Avoidance coping was associated with worse QoL. However, non-cancer life stresses showed the strongest QoL-decreasing influence. QoL-enhancing factors, including social support, were seen clearly only within the breast cancer patients receiving adjuvant treatment. Conclusions: QoL of newly diagnosed cancer patients is highly associated with psychosocial factors. Non-cancer life stresses seem to be very important in the QoL of newly diagnosed cancer patients. Adjuvant treatment may comprise supportive psychosocial factors that enhance QoL in cancer.