Reproductive toxicology. Diethylhexyl phthalate, juvenile exposure, mice.

Background: The objective of this study was to evaluate serum IGF-I levels in postmenopausal women with breast cancer treated primarily with raloxifene. Methods: Twenty-two postmenopausal patients with operable, stage I or II, estrogen receptorpositive carcinomas participated in this study. Following confirmation of diagnosis, the patients received 60 mg of raloxifene for 28 days prior to definitive surgery. Blood samples were collected for evaluation of serum IGF-I levels prior to initiating medication and following a 28-day treatment course. Student's t-test for paired samples was used in the statistical analysis. Significance was established at p < 0.05. Results: Mean serum IGF-I levels preand post-raloxifene treatment were 143.7 ± 9.7 ng/ml and 94.8 ± 7.6 ng/ml, respectively. This reduction in serum IGF-I levels following treatment with raloxifene was statistically significant (p < 0.001). Conclusion: Raloxifene significantly reduced serum IGF-I levels in postmenopausal women with breast cancer. Background Insulin-like growth factor-I (IGF-I) is produced principally in the liver upon stimulation by GH and plays an important role in promoting normal and neoplastic cell proliferation [1-8]. Insulin-like growth factors I and II are almost exclusively bound to IGF binding proteins (IGFBPs), less than 1% circulating freely [7]. There are six types of IGFBP; however, more than 90% of all circulating IGF-I is bound to IGF binding protein-3 (IGFBP-3) [7,9,10]. IGFBP-3 inhibits the action of IGF-I at cell level by competitively binding IGF-I and thereby preventing it from binding to the IGF-I receptor [7]. The IGF system is currently recognized as a risk factor for the principal types of epithelial cancer [11,12]. Studies have shown an association of increased serum levels of IGF-I and decreased levels of IGFBP-3 with an increased risk of breast cancer in premenopausal women [13,14], suggesting that these patients may benefit from measures able to reduce serum IGF-I levels and increase IGFBP-3 levels. Nevertheless, a few studies have shown that some Published: 23 July 2007 International Seminars in Surgical Oncology 2007, 4:18 doi:10.1186/1477-7800-4-18 Received: 16 May 2007 Accepted: 23 July 2007 This article is available from: http://www.issoonline.com/content/4/1/18 © 2007 da Silva et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.