Prediagnostic circulating concentrations of plasma insulin-like growth factor-I and risk of lymphoma in the European Prospective Investigation into Cancer and Nutrition

Abstract

Insulin-like growth factor-I (IG F-I) has cancer promoting activities. However, the hypothesis that circulating IGF-I concentration is related to risk of lymphoma overall or its subtypes has not been examined prospectively. IGF-I co ncentration was measured in pre-diagnostic plasma samples from a nested case-control study of 1072 cases of lymphoid malignancies and 1072 individually matched controls from th e European Prospectiv e Investiga tion into Cancer and Nutrition. Odds ratios (ORs) and c onfidence intervals (CIs) for lymphoma were calculated using conditional logist ic regression. IGF-I concentra tion was not associated with overall lymphoma risk (multivariable-adjusted OR for highest versus lowest third = 0.77 [95% CI=0.57-1.03], P trend = 0.06). There was no statistical evidence of heterogeneity in this association with IGF-I by se x, age at blood collection, tim e between blood collection and diagnosis, age at diagnosis, or body mass index (P heterogeneity for all ≥ 0.05). There were no associations between IGF-I c oncentration and risk for specific BCL subtypes, T-cell lymphoma or Hodgkin lymphoma, although number of cases were small. In this European population, IGF-I concentration wa s not associated with risk of overall lymphoma. This study provides the first prospective evidence on circ ulating IGF-I concentrations and risk of lymphoma. Further prospective data are re quired to examine asso ciations of IGF-I concentrations with lymphoma subtypes