Table 2.

Breast cancer rate per 1,000 P-Y by screening mammogram result and breast density, BCSC

Prior mammogram
Result/recommendation
Number breast
cancer cases
P-Y at riskBreast cancer rate (95% CI)
per 1,000 P-Y
All women
 True-negative43,10511,034,4963.91 (3.87–3.94)
 False-positive, additional imaging4,742861,3655.51 (5.35–5.66)
 False-positive, biopsy888126,6997.01 (6.56–7.48)
By BI-RADS breast density
Almost entirely fat
 True-negative2,206993,5592.22 (2.13–2.31)
 False-positive, additional imaging12333,2913.69 (3.07–4.41)
 False-positive, biopsy235,7743.98 (2.53–5.97)
Scattered fibroglandular density
 True-negative17,8845,070,9113.53 (3.37–3.47)
 False-positive, additional imaging1,737355,1924.89 (4.51–4.95)
 False-positive, biopsy31552,6125.99 (5.09–6.36)
Heterogeneously dense
 True-negative19,0144,143,8304.59 (4.52–4.65)
 False-positive, additional imaging2,372398,2805.96 (5.72–6.20)
 False-positive, biopsy44856,9847.86 (7.15–8.62)
Extremely dense
 True-negative4,001826,1974.84 (4.69–4.99)
 False-positive, additional imaging51074,6026.84 (6.26–7.45)
 False-positive, biopsy10211,3299.00 (7.35–10.92)