Neurotoxic phenomena are among the most common and difficult to treat side effects of chemotherapy. The development of chemotherapy induced peripheral neuropathy (CIPN) is a well-recognized adverse reaction in the peripheral nervous system. Side effects of chemotherapy in the central nervous system, however, particularly changes of cognitive function (in non-medical literature referred to as "chemobrain") are diffuse and difficult to attribute to individual cytostatic drugs. The primary purpose of this study is to assess cognitive function in patients with ovarian and breast cancer before and after systemic chemotherapy with paclitaxel with standardized neuropsychological tests and compare the outcome to patients with benign gynecological tumors and breast cancer without chemotherapy treatment, respectively. Secondary parameters include the assessment of olfactory function, total neuropathy score and cytokine profiles.