Table 2.

Risk of breast cancer by p16 expression in AH

Percentage of cells positive for p16NEventsExpected eventsSIR (95% CI)aPb
0.88
080184.24.24 (2.67–6.73)
1–1078123.53.45 (1.96–6.08)
11–5045112.64.15 (2.30–7.50)
51+3061.73.52 (1.58–7.84)
  • aSIRs and corresponding 95% CI, comparing the observed number of breast cancer events to those expected on the basis of incidence rates from Iowa SEER data. Analyses account for the effects of age and calendar period.

  • bTest for heterogeneity of the SIR across staining levels.