Genetic variation in angiotensin I-converting enzyme (ACE) and breast cancer risk: the multiethnic cohort.

The A-240T and I/D polymorphisms in the angiotensin I-converting enzyme (ACE) gene are markers of circulating ACE levels and have been associated with numerous cardiovascular disease outcomes. More recently, the low-activity A and I alleles at these polymorphic sites have been inversely related with breast cancer risk. We assessed the relationship between the A-240T and I/D ACE variants and breast cancer risk in a case-control analysis (n = 1263 cases with invasive breast cancer and 2269 controls) among African-American, Japanese, Latina, and white women in the Multiethnic Cohort Study. Odds ratios and 95% confidence intervals are presented adjusted for established breast cancer risk factors. Among all women combined, we observed no significant association between the A-240T polymorphism and breast cancer risk. For the I/D polymorphism, contrary to expectation, women with the I/I genotype had a marginally significant increase in breast cancer risk (versus DD genotype: odds ratio, 1.30; 95% confidence interval, 1.05-1.61), although associations were not entirely consistent across ethnic groups. These data do not support the hypothesis that women with lower ACE levels, as predicted by the low-activity A and I ACE alleles, are at reduced risk of breast cancer. Overall, these results suggest that the A-240T and I/D ACE polymorphisms are not likely to be strong predictors of breast cancer risk.