Table 2.

Distribution of breast cancer intrinsic subtypes from PAM50 gene expression assay in the population-based LACE and Pathways studies, in a subcohort overall and by clinicopathologic categories

Clinicopathologic categorya
SubcohortLow-risk endocrine +High-risk endocrine +HER2+, endocrine −Triple negative
n = 1,319n = 298n = 480n = 138n = 405
PAM50 subtype%95% CI%95% CISens/Specb%95% CISens/Specb%95% CISens/Specb%95% CISens/Specb
Luminal A53.149.8–56.576.571.4–81.00.74/0.7440.534.5–46.72.20.7–6.73.01.7–5.2
Luminal B20.517.7–23.614.811.2–19.336.230.6–42.30.59/0.737.44.0–13.24.73.0–7.2
HER2E13.011.3–15.03.72.1–6.617.513.7–22.075.767.8–82.20.23/0.9920.316.6–24.5
Basal-like9.88.8–10.80.30.0–2.02.91.3–6.214.79.7–21.769.965.2–74.20.83/0.96
Normal-like3.62.5–5.44.72.8–7.82.91.4–5.90.02.21.2–4.2
  • aClinicopathologic categories (columns), defined in methods, are based on ER and PR expression, as determined by IHC, HER2 overexpression by IHC, and/or FISH, and tumor grade.

  • bSensitivity and specificity, treating clinicopathologic category as test and the most similar PAM50 subtype classification as the gold standard.