Risk of breast cancer in women who have tested negative for a familial BRCA1/BRCA2 mutation
| Age (years) | Person-years | Ontario rate* | Breast cancers (n) | SIR | |
|---|---|---|---|---|---|
| Expected | Observed | ||||
| SIR, standardised incidence ratio. | |||||
| *Breast cancers per 100 000 per year [8]. | |||||
| 30–35 | 70 | 22.1 | 0.015 | 0 | |
| 36–40 | 119 | 53.7 | 0.064 | 0 | |
| 41–45 | 120 | 102.3 | 0.123 | 2 | |
| 46–50 | 137 | 174 | 0.238 | 1 | |
| 51–55 | 111 | 225.3 | 0.250 | 0 | |
| 56–60 | 72 | 252.9 | 0.182 | 0 | |
| 61–65 | 45 | 282.3 | 0.127 | 0 | |
| 66–70 | 8 | 335.6 | 0.027 | 0 | |
| Total | 720 | 1.026 | 3 | 2.9 | |