Premenopausal insulin-like growth factor-I serum levels and changes in breast density over menopause

Cancer Epidemiol Biomarkers Prev. 2007 Mar;16(3):451-7. doi: 10.1158/1055-9965.EPI-06-0642.

Abstract

Background: A high proportion of glandular and stromal tissue in the breast (percentage breast density) is a strong risk factor for breast cancer development. Insulin-like growth factor-I (IGF-I) is hypothesized to influence breast cancer risk by increasing breast density.

Objectives: We studied the relation between premenopausal circulating IGF-I levels and premenopausal and postmenopausal, absolute nondense and dense area, and percentage breast density as well as changes in these measures over menopause.

Design and methods: Mammograms and blood samples of 684 premenopausal participants of the Prospect-European Prospective Investigation into Cancer and Nutrition cohort were collected at baseline. A second mammogram of these women was collected after they became postmenopausal. Premenopausal IGF-I levels were measured in serum. Premenopausal and postmenopausal breast measures were assessed using a computer-assisted method. Mean values of breast measures were calculated for quartiles of serum IGF-I using linear regression analysis.

Results: Women with higher premenopausal IGF-I levels showed a slightly smaller decrease in dense area over menopause (-12.2 cm2 in the highest versus -12.9 cm2 in the lowest quartile; P trend = 0.58) and, at the same time, a smaller increase in the nondense (fat) area (P trend = 0.09). Due to the changes over menopause, high premenopausal IGF-I serum levels were associated with lower nondense area (P trend = 0.05), somewhat higher dense area (P trend = 0.66), and consequently higher percentage breast density (P trend = 0.02) after menopause.

Conclusion and discussion: Women with higher premenopausal IGF-I levels have a smaller increase in nondense area and also a slightly smaller decrease in absolute dense area during menopause, resulting in higher breast density after menopause.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast / physiology*
  • Breast Neoplasms / blood
  • Female
  • Humans
  • Insulin-Like Growth Factor Binding Protein 1 / blood*
  • Linear Models
  • Mammography
  • Menopause / blood*
  • Middle Aged
  • Premenopause / blood*
  • Prospective Studies
  • Surveys and Questionnaires

Substances

  • Insulin-Like Growth Factor Binding Protein 1