Table 4.
Breast density and Chlebowski’s abbreviated model for ER-positive invasive breast cancer: NSABP STAR
| Variables | HRa | 95% CI | P-value |
|---|---|---|---|
| Age | 1.03 | 1.02 – 1.05 | <.001 |
| No. 1° relatives with breast cancer | 0.82 | 0.62 – 1.08 | 0.17 |
| No. previous breast biopsiesb | 1.27 | 1.08 – 1.50 | 0.004 |
| Breast density | 1.24 | 1.03 – 1.49 | 0.02 |
a
HR for age is per one year increase; reference groups for number of relatives and breast biopsies were “0”; HR for breast density is per increase of BI-RADS density category.
b
Those with unknown biopsy data were excluded from analyses.
Abbreviations: HR, hazard ratio; CI, confidence interval; ER, estrogen receptor; BI-RADS, The American College of Radiology Breast Imaging Reporting and Data System.