Age at calculation % risk with no HRT 3 years combination HRT 5 years combination HRT 10 years combination HRT 15 years combination HRT 3 years oestrogen only HRT 5 years oestrogen only HRT 10 years oestrogen only HRT 15 years oestrogen only HRT
40 7.21 7.39 7.59 8.39 9.43 7.26 7.33 7.55 7.85
45 6.76 7.02 7.28 8.21 9.3 6.83 6.91 7.17 7.49
50 6.1 6.41 6.7 7.69 8.92 6.19 6.28 6.55 6.91
55 5.3 5.63 5.94 7.06 8.47 5.39 5.49 5.8 6.21
60 4.44 4.81 5.17 6.45 7.95 4.54 4.65 5.01 5.44
65 3.48 3.9 4.32 5.67 6.75 3.6 3.73 4.1 4.39
70 2.37 2.84 3.25 4.21   2.5 2.62 2.87  
75 1.14 1.57 1.72     1.26 1.28    

Hormone replacement therapy and breast cancer: estimate of risk