Table 2.

Impacta of targeting a subset of European-American women for breast cancer preventive strategies

Percentage of population at high risk (α)Lifetime risk in low-risk (%)Risk for high-risk relative to low-riskRisk for low-risk relative to populationPercentage of cases who are high-risk (Sn)Percentage of noncases who are high-risk (1-Sp)Percentage of high-risk who are cases (PPV)Percentage of low-risk who are noncases (NPV)NNTb
Current knowledge of genetic susceptibility alleles (risk score variance, 0.35)
Best-case scenario (risk score variance, 1.44)
  • aAssuming that the lifetime risk of developing breast cancer is 12.68% based upon estimates for the U.S. white female population (19).

  • bNNT, number of women who must be targeted to avoid one breast cancer death, assuming one sixth of all breast cancers are fatal and targeting prevents death from half of them.