A Novel Automated Mammographic Density Measure and Breast Cancer Risk
Journal of the National Cancer Institute, 07/05/2012
Heine JJ et al. – The association between the automated variation measure and the risk of breast cancer is at least as strong as that for percent density.Methods
- Three clinic-based studies were included: a case–cohort study of 217 breast cancer case subjects and 2094 non-case subjects and two case–control studies comprising 928 case subjects and 1039 control subjects and 246 case subjects and 516 control subjects, respectively.
- Percent density was estimated from digitized mammograms using the computer-assisted Cumulus thresholding program, and variation was estimated from an automated algorithm.
- The authors estimated hazards ratios (HRs), odds ratios (ORs), the area under the receiver operating characteristic curve (AUC), and 95% confidence intervals (CIs) using Cox proportional hazards models for the cohort and logistic regression for case–control studies, with adjustment for age and body mass index.
- They performed a meta-analysis using random study effects to obtain pooled estimates of the associations between the two mammographic measures and breast cancer.
- All statistical tests were two-sided.
- The variation measure was statistically significantly associated with the risk of breast cancer in all three studies (highest vs lowest quartile: HR=7.0 [95% CI=4.6 to 10.4]; OR=10.7 [95% CI=7.5 to 15.3]; OR=2.6 [95% CI=1.6 to 4.2]; all P trend<.001).
- In two studies, the risk estimates and AUCs for the variation measure were greater than those for percent density (AUCs for variation=0.71 and 0.76; AUCs for percent density=0.65 and 0.65), whereas in the third study, these estimates were similar (AUC for variation=0.60 and AUC for percent density=0.61).
- A meta-analysis of the three studies demonstrated a stronger association between variation and breast cancer (highest vs lowest quartile: RR=3.6, 95% CI=1.9 to 7.0) than between percent density and breast cancer (highest vs lowest quartile: RR=2.3, 95% CI=1.9 to 2.9).