title: Circulating Insulin-Like Growth Factor-1 Level and Ovarian Cancer Risk.
abstract: OBJECTIVE
  Insulin-like growth factor-1 (IGF-1) has an important role in cells' proliferation, differentiation and apoptosis, and it may be involved in carcinogenesis. Several epidemiological studies assessed the association between circulating IGF-1 level and ovarian cancer risk, but there was still no conclusive finding.
  
  
  METHODS
  A meta-analysis of published studies was performed to assess the association between circulating IGF-1 level and ovarian cancer risk. The summary odds ratio (OR) with 95% confidence interval (95%CI) was calculated through meta-analysis to evaluate the strength of the association.
  
  
  RESULTS
  Five eligible studies were included into the meta-analysis, which involved a total of 2,028 cases of ovarian cancer and 4,625 controls. Meta-analysis of total 5 studies showed that high circulating IGF-1 level was correlated with decreased risk of ovarian cancer (OR = 0.84, 95%CI 0.74-0.97, P = 0.013). After adjusting for heterogeneity, high circulating IGF-1 level was still correlated with decreased risk of ovarian cancer (OR = 0.83, 95%CI 0.72-0.95, P = 0.007). Subgroup analysis by age showed that circulating IGF-1 level was not correlated with ovarian cancer risk in women both less than 55 years and more than 55 years. However, after adjusting for heterogeneity, high circulating IGF-1 level was correlated with decreased ovarian cancer risk in women less than 55 years (OR = 0.82, 95%CI 0.72-0.94, P = 0.004).
  
  
  CONCLUSIONS
  Our meta-analysis suggests that high circulating IGF-1 level may be correlated with decreased ovarian cancer risk, especially in women less than 55 years. More studies are needed to further assess the association between circulating IGF-1 level and ovarian cancer risk in the future.
authors: Department of Gynaecology and Obstetrics, the First Hospital of Jilin University, Changchun, China.
authors: Yiyang
authors: Y
authors: Li
authors: Yang
authors: Y
authors: Li
authors: Jialing
authors: J
authors: Zhang
authors: Changjun
authors: C
authors: Zheng
authors: He
authors: H
authors: Zhu
authors: Huimei
authors: H
authors: Yu
authors: Limei
authors: L
authors: Fan
mesh_terms: D000367:Age Factors; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008875:Middle Aged; D016017:Odds Ratio; D010051:Ovarian Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D010053:Ovary / Q000473:pathology; D012307:Risk Factors
chemical_list: D007334:Insulin-Like Growth Factor I