Table 1a.
Cumulative risk of developing breast cancer from age 50.0–80.0 years, according to family history and MHT use for oestrogen-only and combined-all MHT
| Family history | MHT type | Current age, years | 51.0 | 52.0 | 53.0 | 54.0 | 55.0 | 60.0 | 65.0 | 70.0 | 75.0 | 80.0 | Likelihood of developing breast cancer age 50–80. One in: | Likelihood of developing breast cancer age 50–80 attributable to MHT. One in: |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average woman | Population risk | 0.3% | 0.5% | 0.8% | 1.0% | 1.3% | 2.8% | 4.4% | 6.3% | 8.1% | 9.9% | 10.1 | — | |
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| None | No MHT | 0.2% | 0.5% | 0.7% | 1.0% | 1.2% | 2.7% | 4.3% | 6.2% | 8.0% | 9.8% | 10.2 | — | |
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| Oestrogen only | MHT used age 50.0–51.0 | 0.3% | 0.6% | 0.8% | 1.1% | 1.3% | 2.9% | 4.6% | 6.6% | 8.4% | 10.2% | 9.8 | 256 | |
| MHT used age 50.0–55.0 | 0.3% | 0.6% | 0.9% | 1.3% | 1.5% | 3.1% | 4.9% | 6.9% | 8.7% | 10.5% | 9.5 | 148 | ||
| MHT used age 50.0–60.0 | 0.3% | 0.6% | 0.9% | 1.3% | 1.5% | 3.3% | 5.1% | 7.3% | 9.0% | 10.8% | 9.2 | 98 | ||
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| Combined — all types | MHT used age 50.0–51.0 | 0.3% | 0.5% | 0.7% | 1.1% | 1.3% | 2.9% | 4.6% | 6.6% | 8.4% | 10.2% | 9.8 | 256 | |
| MHT used age 50.0–55.0 | 0.3% | 0.8% | 1.1% | 1.6% | 1.9% | 3.7% | 5.5% | 7.7% | 9.5% | 11.3% | 8.9 | 67 | ||
| MHT used age 50.0–60.0 | 0.3% | 0.8% | 1.1% | 1.6% | 1.9% | 4.8% | 6.9% | 9.4% | 11.2% | 12.9% | 7.7 | 32 | ||
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| Modest family history (affected FDR age 60) | None | No MHT | 0.4% | 0.8% | 1.2% | 1.6% | 2.0% | 4.3% | 6.7% | 9.3% | 11.7% | 13.8% | 7.2 | — |
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| Oestrogen only | MHT used age 50.0–51.0 | 0.5% | 0.9% | 1.4% | 1.8% | 2.2% | 4.6% | 7.2% | 9.9% | 12.3% | 14.4% | 6.9 | 170 | |
| MHT used age 50.0–55.0 | 0.5% | 1.0% | 1.5% | 2.0% | 2.6% | 5.0% | 7.6% | 10.4% | 12.7% | 14.8% | 6.7 | 98 | ||
| MHT used age 50.0–60.0 | 0.5% | 1.0% | 1.5% | 2.0% | 2.6% | 5.3% | 8.0% | 10.9% | 13.2% | 15.3% | 6.5 | 66 | ||
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| Combined — all types | MHT used age 50.0–51.0 | 0.5% | 0.8% | 1.3% | 1.7% | 2.1% | 4.6% | 7.1% | 9.8% | 12.3% | 14.4% | 6.9 | 170 | |
| MHT used age 50.0–55.0 | 0.6% | 1.3% | 1.9% | 2.5% | 3.2% | 5.9% | 8.6% | 11.6% | 14.0% | 16.0% | 6.2 | 45 | ||
| MHT used age 50.0–60.0 | 0.6% | 1.3% | 1.9% | 2.5% | 3.2% | 7.6% | 10.7% | 14.1% | 16.4% | 18.4% | 5.4 | 22 | ||
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| Intermediate family history (affected FDR age 40) | None | No MHT | 0.5% | 1.0% | 1.5% | 2.1% | 2.6% | 5.4% | 8.4% | 11.5% | 14.1% | 16.4% | 6.1 | — |
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| Oestrogen only | MHT used age 50.0–51.0 | 0.7% | 1.2% | 1.7% | 2.3% | 2.9% | 5.8% | 9.0% | 12.3% | 14.8% | 17.1% | 5.8 | 140 | |
| MHT used age 50.0–55.0 | 0.6% | 1.3% | 1.9% | 2.7% | 3.3% | 6.3% | 9.5% | 12.8% | 15.4% | 17.6% | 5.7 | 80 | ||
| MHT used age 50.0–60.0 | 0.6% | 1.3% | 1.9% | 2.7% | 3.3% | 6.7% | 10.0% | 13.4% | 16.0% | 18.2% | 5.5 | 55 | ||
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| Combined — all types | MHT used age 50.0–51.0 | 0.7% | 1.1% | 1.6% | 2.2% | 2.8% | 5.7% | 8.9% | 12.1% | 14.8% | 17.1% | 5.8 | 140 | |
| MHT used age 50.0–55.0 | 0.8% | 1.6% | 2.4% | 3.3% | 4.1% | 7.4% | 10.8% | 14.4% | 16.9% | 19.1% | 5.2 | 37 | ||
| MHT used age 50.0–60.0 | 0.8% | 1.6% | 2.4% | 3.3% | 4.1% | 9.5% | 13.3% | 17.3% | 19.7% | 21.9% | 4.6 | 18 | ||
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| Strong family history (two affected FDR age 50) | None | No MHT | 0.7% | 1.3% | 2.0% | 2.7% | 3.4% | 7.0% | 10.6% | 14.2% | 17.1% | 19.6% | 5.1 | — |
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| Oestrogen only | MHT used age 50.0–51.0 | 0.9% | 1.6% | 2.3% | 3.0% | 3.8% | 7.6% | 11.4% | 15.1% | 18.0% | 20.5% | 4.9 | 114 | |
| MHT used age 50.0–55.0 | 0.9% | 1.7% | 2.6% | 3.4% | 4.3% | 8.2% | 12.0% | 15.8% | 18.7% | 21.1% | 4.7 | 66 | ||
| MHT used age 50.0–60.0 | 0.9% | 1.7% | 2.6% | 3.4% | 4.3% | 8.6% | 12.6% | 16.6% | 19.4% | 21.8% | 4.6 | 45 | ||
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| Combined — all types | MHT used age 50.0–51.0 | 0.9% | 1.4% | 2.1% | 2.9% | 3.6% | 7.4% | 11.2% | 15.0% | 18.0% | 20.5% | 4.9 | 114 | |
| MHT used age 50.0–55.0 | 1.1% | 2.1% | 3.2% | 4.3% | 5.4% | 9.5% | 13.6% | 17.7% | 20.5% | 22.9% | 4.4 | 30 | ||
| MHT used age 50.0–60.0 | 1.1% | 2.1% | 3.2% | 4.3% | 5.4% | 12.2% | 16.8% | 21.3% | 23.9% | 26.2% | 3.8 | 15 | ||
FDR = first-degree relative. MHT = menopausal hormone therapy. Cumulative risks are presented: the proportion of individuals expected to develop breast cancer from age 50.0 years to the current age specified. Family history parameters include the number of first-degree relatives affected by breast cancer (one or two) and their age at diagnosis (40, 50, or 60 years). MHT use parameters include type of MHT used and age of use.