Polymorphisms and Circulating Levels in the Insulin-Like Growth Factor System and Risk of Breast Cancer: A Systematic Review
We reviewed all English-language articles on associations among circulating levels of the insulin-like growth factors (IGF) and their binding proteins (IGFBP), polymorphisms in their genes, and breast cancer risk. In premenopausal women, five of eight IGF-I studies and four of six IGFBP-3 studies of...
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Published in | Cancer epidemiology, biomarkers & prevention Vol. 14; no. 1; pp. 2 - 19 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Philadelphia, PA
American Association for Cancer Research
01.01.2005
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Subjects | |
Online Access | Get full text |
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Summary: | We reviewed all English-language articles on associations among circulating levels of the insulin-like growth factors (IGF)
and their binding proteins (IGFBP), polymorphisms in their genes, and breast cancer risk. In premenopausal women, five of
eight IGF-I studies and four of six IGFBP-3 studies of circulating levels found that women in the highest quantile had more
than twice the risk of developing breast cancer of those in the lowest, although in some this effect was only apparent at
young ages. In postmenopausal women, however, there was no consistent effect. A simple sequence length polymorphism 1 kb 5′
to IGF-I was examined in relation to circulating levels of IGF-I (12 studies) or breast cancer risk (4 studies), but there was no
convincing evidence of any effect. For an A/C polymorphism 5′ to IGFBP-3 , all three studies were consistent with a modest effect on circulating levels, but no evidence of a direct effect on breast
cancer risk was seen in the only relevant study. Variation within the reference range of IGF-I and IGFBP-3 may confer only
modest increases in breast cancer risk, and any single polymorphism may only account for a small proportion of that variation.
Nevertheless, population attributable fractions for high circulating levels of IGF-I and IGFBP-3 and for common genetic variants
could be substantial. Further large studies, or combined analysis of data from existing studies, are needed to quantify these
effects more precisely. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Feature-4 ObjectType-Undefined-1 ObjectType-Review-2 ObjectType-Article-3 |
ISSN: | 1055-9965 1538-7755 |
DOI: | 10.1158/1055-9965.2.14.1 |