Einfluß der Lebensqualität, möglicher Veränderungen des Schlafverhaltens und Verhalten der Knochenstoffwechselparameter nach einjähriger Therapie mit einem Aromatasehemmer auf die Compliance in der adjuvanten Therapie des Mammakarzinoms

Background Medical treatment can only unfold its therapeutic effect, if its taken as recommended. Causes for discontinuation of treatment can be, among other things, poor communication between doctor and patient, insufficient medical care and side effects caused by treatment. In case of endocrine treatment of primary breast cancer poor compliance accompanies an increased mortality rate. Side effects such as insomnia, decrease in quality of life, as well as change of bone metabolism seem to influence a patient's compliance to treatment. Methods The investigation was conducted parallel to the COMPAS-study („Influence of an oral or written Patient information program compared to standard clinical care on adherence and persistence with an aromatase inhibitor in the adjuvant treatment of primary breast cancer“) and included 181 patients with primary breast cancer who received endocrine treatment with an aromatase inhibitor. In this monocentric, three-armed, randomized, partially blinded parallel group study the patients were contacted with personalized letters or telephone contacts for 12 months and compared to a control group with regard to compliance. Within our investigation the main study was added by standardized questionnaires to evaluate side effects as well as a blood test to examine bone makers at baseline and after 12 month of aromatase inhibtor therapy. The aim of the study was to show if potential side effects like insomnia, change of quality of life as well as the characteristics of bone markers under endocrine treatment influence the parameter of compliance. Results There was no significant difference between comliant and non-compliant patients in quality of life Regarding insomnia, the non-compliant group had a statistical significant higher rate of daytime drowsiness. A significant increase in both the bone resorption marker CTX and the bone formation marker tP1NP after 12 month of therapy with an aromatase inhibitor was observed. Both markers showed a much higher increase in compliant patients. As expected, the investigation of serum concentrations of estradiol was suppressed more in the group of compliant patients. Conclusion In this investigation, quality of life could not be shown to be significantly influenced by aromatase inhibitor therapy. In the field of sleep patterns, the significance of daytime drowsiness can be disregarded because it must be assumed that other factors that disturb a patient's nighttime sleep showed a statistically significance. The results of bone metabolism showed an increase of bone resorption marker as well as bone formation marker after 12 month of endocrine treatment. In former studies an increase of bone formation marker was only shown in treatment with exemestane. However, in these studies the observation period was choosen significantly shorter. Further scientific research with longer periods under observation is needed to analyze the effect of aromatase inhibitors on bone metabolism.