Primary hypothesis:
\*The adverse effects of cancer and cancer therapy on cognitive function in breast cancer patients are entirely or partly mediated by stress and the ensuing dysfunction of the HPA-axis.
Secondary objectives:
* Determining the effect of cancer diagnosis, chemotherapy, disease-related stress, acute stress response, posttraumatic stress disorder, posttraumatic stress symptoms, anxiety, and depression on the HPA-axis in breast cancer patients
* Determining the effect of cognitive dysfunction assessed with neuropsychological tests, cancer diagnosis, chemotherapy, disease-related stress, acute stress response, posttraumatic stress disorder, posttraumatic stress symptoms, anxiety, and depression on subjective cognitive function in breast cancer patients
* Prevalence of acute stress response, posttraumatic stress disorder and posttraumatic stress symptoms, and extent of cancer-specific stress in breast cancer patients treated with or without chemotherapy
