IGFBP3 A-202C polymorphism and breast cancer susceptibility: a meta-analysis involving 33,557 cases and 45,254 controls.

Published data on the association between insulin-like growth factor binding protein 3 (IGFBP3) A-202C polymorphism and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Crude ORs with 95% CIs were used to assess the strength of association between them. A total of 27 studies including 33,557 cases and 45,254 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with IGFBP3 C allele when all studies were pooled into the meta-analysis (CC vs. AA: OR = 1.06, 95% CI = 1.02-1.11; dominant model: OR = 1.04, 95% CI = 1.00-1.07). In the subgroup analysis by ethnicity, significantly increased risk was found for Caucasians (AC vs. AA: OR = 1.04, 95% CI = 1.00-1.08; CC vs. AA: OR = 1.05, 95% CI = 1.01-1.10; dominant model: OR = 1.04, 95% CI = 1.00-1.08) and Asians (CC vs. AA: OR = 1.35, 95% CI = 1.02-1.78; recessive model: OR = 1.38, 95% CI = 1.05-1.82). When stratified by study design, statistically significantly elevated risk was found among population-based studies (CC vs. AA: OR = 1.06, 95% CI = 1.01-1.11; dominant model: OR = 1.03, 95% CI = 1.00-1.07). In the subgroup analysis by menopausal status, no statistically significantly increased risk was found among premenopausal or postmenopausal women. In conclusion, this meta-analysis suggests that the IGFBP3 C allele is a low-penetrant risk factor for developing breast cancer.