The purpose of this work was to study changes in serum levels of interleukins, growth factors and angiogenin during different stages of endometrial cancer progression. Serum levels were assayed by enzyme-linked immunosorbant assay in 59 women with stages I-IV of endometrial cancer (study subjects: stage I, n = 20; stage II, n = 8; stage III, n = 5; stage IV, n = 6) and compared to the serum levels in 20 women without cancer as control subjects. Patients with endometrial cancer had varied serum levels of interleukins and growth factors. There was a significant increase in serum levels of angiogenin in all stages of tumor progression. Levels of interleukin-8 (IL-8), IL-10 and transforming growth factor beta (TGF beta) were significantly elevated in patients with stages I and II carcinoma. The serum levels of tumor necrosis factor alpha (TNF alpha), granulocyte/macrophage-colony-stimulating factor, basic fibroblast growth factor (BFGF), IL-7 and IL-2 were significantly elevated in patients with stages II and III carcinoma and the serum level of tumor necrosis factor beta (TNF beta) was slightly elevated in patients with stage II carcinoma only. The serum levels of IL-1 alpha, IL-1 beta and IL-6 were not elevated in endometrial cancer patients in any of the clinical stages. The results showed that progression of endometrial cancer is associated with increased serum levels of cytokines, growth factors and angiogenin, which possibly amplify angiogenesis during different clinical stages.