Coskun, U.Gunel, N.Sancak, B.Onuk, E.Bayram, M.Cihan, A.2020-06-252020-06-252004closedAccess0009-91041365-2249https://doi.org/10.1111/j.1365-2249.2004.02579.xhttps://hdl.handle.net/20.500.12587/3238Vascular endothelial growth factor (VEGF) is a multi-functional cytokine that has been suggested to be a major angiogenic factor in breast cancer. Nitric oxide (NO) is a potent biological molecule that partipicates in the multi-step process of carcinogenesis. Interleukin (IL)-18 has been shown to have potent anti-tumour effects. In this study, we investigated the effect of tamoxifen therapy on serum VEGF, NO and IL-18 activity in breast cancer patients. Serum levels of VEGF, nitrate + nitrite and IL-18 were measured in 34 postmenopausal breast cancer patients before and 3 months after the tamoxifen therapy. Both serum VEGF and IL-18 levels decreased after tamoxifen therapy (P = 0.051, P < 0.05, respectively). Serum VEGF levels increased in patients with endometrial thickness, while patients without endometrial thickness had a significant reduction in serum VEGF levels after therapy (P < 0.05). Serum nitrate + nitrite levels increased after the therapy, but this was not statistically significant (P > 0.05). A decrease in serum VEGF levels with tamoxifen therapy may be a reflection of reduced angiogenic activity in patients without endometrial thickness. The negative effect of tamoxifen therapy on IL-18, which is known to have a potent antitumour activity, may be related to the decreased tumour growth by induction of NO and reduction of VEGF activity as a feedback mechanism.eninfo:eu-repo/semantics/closedAccessangiogenesisapoptosisbreast cancerhormone therapynitratenitriteArticle137354655110.1111/j.1365-2249.2004.02579.x2-s2.0-434465957015320904Q2WOS:000223469800012Q2