Table 1.
Calculation of hazard ratio for risk of other-cause death among localized, invasive breast cancer cases relative to age-matched population*
| Year interval | Observed interval survival (OBS) | Expected interval survival (EXP) | Cause-specific interval survival (CS) | Other-cause interval probability (OC) | Hazard ratio† |
|---|---|---|---|---|---|
| < 1 yr | 98.5% | 98.1% | 99.5% | 1.0% | 0.52 |
| 1 to <2 yr | 97.9% | 98.0% | 99.2% | 1.3% | 0.64 |
| 2 to <3 yr | 97.4% | 97.9% | 99.0% | 1.6% | 0.76 |
| 3 to <4 yr | 97.4% | 97.8% | 99.0% | 1.6% | 0.72 |
| 4 to <5 yr | 97.1% | 97.6% | 99.0% | 1.9% | 0.79 |
| 5 to <6 yr | 97.1% | 97.5% | 99.1% | 2.0% | 0.80 |
| 6 to <7 yr | 96.8% | 97.4% | 99.1% | 2.3% | 0.88 |
| 7 to <8 yr | 96.5% | 97.2% | 99.2% | 2.7% | 0.96 |
* The table shows Surveillance, Epidemiology, and End Results 18 registries observed, expected, and cause-specific survival by year following diagnosis for localized, invasive breast cancer cases aged 40 and above diagnosed between 2003 and 2010. For each interval of follow-up we calculate the probability of other-cause (noncancer) death within the interval as OC=CS-OBS.
† The hazard ratio (HR) is given by log(1-OC)/log(EXP). The average HR over the first eight years is 0.75.