Mammographic density phenotypes and risk of breast cancer: a meta-analysis.
Level 3 - non-randomized controlled study
Meta-analysis of case-control studies
PubMed 24816206 · doi:10.1093/jnci/dju078
What was done
A meta-analysis of 13 case-control studies evaluated the associations between one standard deviation (SD) increments in mammographic density phenotypes (absolute dense area, absolute nondense area, and percentage dense area) and breast cancer risk. Random-effects models were used to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for age, body mass index, and parity, with additional models further adjusting for absolute dense area.
What was found
In premenopausal women (1,776 cases, 2,834 controls), pooled ORs per 1-SD increment were 1.37 (95% CI = 1.29 to 1.47) for absolute dense area, 0.78 (95% CI = 0.71 to 0.86) for absolute nondense area, and 1.52 (95% CI = 1.39 to 1.66) for percentage dense area. In postmenopausal women (6,643 cases, 11,187 controls), corresponding ORs were 1.38 (95% CI = 1.31 to 1.44), 0.79 (95% CI = 0.73 to 0.85), and 1.53 (95% CI = 1.44 to 1.64). After further adjustment for absolute dense area, the association for absolute nondense area attenuated to OR 0.82 (95% CI = 0.71 to 0.94; P heterogeneity = .02) in premenopausal women and OR 0.85 (95% CI = 0.75 to 0.96; P heterogeneity < .01) in postmenopausal women.
Why it matters
Percentage dense area is a stronger predictor of breast cancer risk than absolute dense area in both premenopausal and postmenopausal women. The apparent protective association of absolute nondense area is attenuated after accounting for absolute dense area, leaving its independent role uncertain.
Limits
All included studies were case-control designs, which are prone to selection and recall biases. Statistically significant heterogeneity was present across studies when evaluating absolute nondense area after dense area adjustment, and specific density measurement methods were not reported in the abstract.
Cited by
- supports Higher breast tissue density is associated with an increased lifetime risk of developing breast cancer.