The objective of this study was to investigate the influence of high dose MPA on serum cholesterol, triglyceride, phospholipids as well as free fatty acids given to 17 patients with metastatic breast cancer. Before the therapy, the patients with cancer revealed higher level in serum cholesterol, triglyceride, phospholipids and C 12:0, C 18:0 as we found it in the control (13 patients without cancer). There was no significant change in lipid parameters by treatment with MPA whereas cortisol decreases and insulin increases under therapy. The results are discussed under biochemical aspects.