Table 4.

Estimated joint effects of quantitative mammographic features identified as independent predictors of subsequent risk of breast cancer, Guernsey IV study, United Kingdom

HR* (95% CI)P
A. Model specification with the explanatory variables on the original continuous scale
Total area of dense tissue (cm2)
HR* per 1 SD increase1.59 (1.29-1.94)<0.001
Lacunarity
HR* per 1 SD increase0.61 (0.47-0.78)<0.001
B. Model specification with the explanatory variables grouped into categories
Total area of dense tissue (cm2), fourths
0.391.00 (baseline)
18.82.23 (1.17-4.26)
30.23.14 (1.65-5.97)
45.43.73 (1.85-7.51)<0.001
Lacunarity (fourths)
4.161.00 (baseline)
4.880.62 (0.36-1.05)
4.990.43 (0.23-0.79)
5.100.46 (0.24-0.89)0.006
  • * HRs and 95% CI adjusted for age, age at leaving full time education, social class, job status, parity, height, BMI at GIII, BMI change from GIII to GIV, and the other variable in the table.

  • P value for likelihood ratio test for linear trend.