Lebensqualität in der Onkologie: Die Rolle von Behandlungserwartungen und Lebenszielen

Due to advanced medical care the life expectancy of oncological patients increases, therefore maintaining and enhancing their quality of life is of high importance. This dissertation has two main purposes. The first aim is to analyze the influence of two predictors (treatment expectations and life goals) on different levels of oncological patients‘ quality of life. The second aim is to develop an intervention program to enhance quality of life. Treatment expectations can influence the occurrence of side effects hence influencing quality of life during medication intake. More than half of the patients with breast cancer discontinue their treatment with endocrine therapy during the indicated treatment period because they suffer from side effects and a reduced quality of life. Study I evaluated the role of patients’ expectations on side effects and quality of life in this patient population. After three months and two years of medication, in 107 and 88 patients, respectively, pre-treatment expectations significantly predicted long-term side effects and quality of life in multivariate models controlling for relevant medical and psychological variables. Building on the results of study I, study II and study III examine if the psychological Side Effect Prevention Program (SEPT) can contribute to an optimized treatment through the modification of expectations. Study II presents the study design, the psychological intervention and the measurements in order to evaluate the effects of SEPT. In a randomized controlled trial, 184 female breast cancer patients are assigned to receive either SEPT, standard medical care or a supportive intervention at the start of adjuvant endocrine treatment. Side effects and quality of life three months after the start of endocrine therapy serve as primary outcomes. Study III describes the concrete psychological interventions illustrated by two case reports. While the results support a general feasabilty and provide narrative evidence of the sucess of the program, the effectiveness still has to be proved in the main analysis. Life goals can be threatened by the diagnosis of cancer. Study IV analyses the influence of life goal adjustment on global quality of life. 86 oncological patients were assessed during rehabilitation. Results show that making more progress in accomplishing attainable life goals and disengaging from probably unattainable goals are associated with higher global quality of life. Cancer patients’ perceived global quality of life might be better explained through life goal adjustment processes than through clinical or sociodemographic factors. Altogether the results of this dissertation indicate that negative pre-treatment expectations increase the risk of side effects and a reduced quality of life in breast cancer patients. Furthermore, optimizing individual expectations might be a promising strategy to improve side effect burden and quality of life during longer-term drug intake. Life goal adjustment is associated with the global quality of life and should be included in rehabilitation programs. Taken together the results presented in this dissertation could help to improve the health care of oncological patients.