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TUESDAY, March 17, 2020 (HealthDay News) — There seems to be a causal association between circulating insulin-like growth factor-1 (IGF-1) concentrations and breast cancer, according to a study published online March 10 in the Annals of Oncology<\/i>.<\/p>\n
Neil Murphy, Ph.D., from the International Agency for Research on Cancer in Lyon, France, and colleagues examined the association between circulating IGF-1 concentrations and incident breast cancer risk in 206,263 women from the U.K. Biobank. In a subsample of 6,711 women, hazard ratios were corrected for regression dilution using repeat IGF-1 measures. In addition, in Mendelian randomization (MR) analyses, genetic variants associated with IGF-1 and IGF-binding protein-3 (IGFBP-3) levels were identified and their association with breast cancer was analyzed using data for 122,977 cases and 105,974 controls.<\/p>\n
The researchers identified 4,360 incident breast cancer cases after a median follow-up of 7.1 years in the U.K. Biobank. Higher IGF-1 concentrations were associated with an increased risk for breast cancer in multivariable-adjusted models (hazard ratio per 5-nmol\/L increment of IGF-1, 1.11; 95 percent confidence interval [CI], 1.07 to 1.16). In the MR analyses, greater breast cancer risk was seen in association with a 5-nmol\/L increment in genetically predicted IGF-1 concentration (odds ratio, 1.05; 95 percent CI, 1.01 to 1.10; P = 0.02); a similar effect estimate was seen for estrogen-positive tumors, but not for estrogen-negative tumors. There was no association seen between genetically predicted IGFBP-3 concentrations and breast cancer risk (odds ratio per 1-standard deviation increment, 1.00; 95 percent CI, 0.97 to 1.04; P = 0.98).<\/p>\n
“This result suggests that pharmacological or lifestyle interventions targeting the IGF pathway may be beneficial in preventing breast tumorigenesis,” the authors write.<\/p>\n