Insulin-like growth factor type 1 (IGF-1) and IGF binding protein-3 in patients with ewing sarcoma family of tumors

Background. Ewing sarcoma family of tumors (ESFTs) are the second most comm on bone tumor, that most often affects persons ages 3-40 years. The ESFTs r ely on signaling through the insulin-like growth factor-1 receptor (IGF-1R) for growth and transformation. The current studies were performed to deter mine the levels of IGF-1 and IGF binding protein-3 (IGFBP-3) in patients wi th ESFT. The authors then performed an exploratory analysis to evaluate whe ther IGF parameters could differentiate event free or overall survival in E SFT patients. Methods. The authors measured serum levels of IGF-1 and IGFBP-3 by using a radioimmuno assay from 111 patients with ESFT with a median follow-up of 13 years from diagnosis. Results. The IGF-1 levels were lower among patients with metastatic disease to the bones or the bone marrow compared with patients without metastasis to these 2 sites (p2=0.021 and 0.0038, respectively). IGFBP-3 is known to s equester IGF-1; the ratios of IGFBP-3 to IGF-1 were evaluated. Patients wit h metastatic disease to any site had higher IGFBP-3 to IGF-1 ratios than pa tients with localized disease (p2=0.0067). There was a trend toward increas ed survival in patients with localized disease who had high IGFBP-3 to IGF- 1 levels. Metastatic patients showed a similar trend. Conclusions. Levels of IGF-1 and IGFBP-3 in ESFT patients can identify pati ents with the most widespread disease. The IGFBP-3 to IGF-l ratio in patien ts with either localized or metastatic disease identified patients with a t rend toward increased survival. Further prospective evaluation with higher patient numbers might show a prognostic role for the IGFBP-3 to IGF-l ratio in patients with ESFT. Cancer 2001;92:2941-7. (C) 2001 American Cancer Soc iety.