Table 3.
Ten-Year Comparisons of Predicted and Observed IBTR Estimates
| Group | No. of Patients | No. of IBTR Events | Predicted 10-Year IBTR! Version 2.0 Estimates (SE) |
95% CI Predicted | Observed 10-Year IBTR Estimates (SE) |
95% CI Observed | P (t test) | ||
|---|---|---|---|---|---|---|---|---|---|
| % | SE | % | SE | ||||||
| 1 IBTR < 3% | 283 | 2 | 2.2 | 0.03 | 2.1 to 2.2 | 1.3 | 1.0 | 0.3 to 5.5 | .4 |
| 2 IBTR 3%-5% | 237 | 11 | 3.8 | 0.04 | 3.7 to 3.8 | 3.5 | 1.3 | 1.7 to 7.2 | .8 |
| 3 IBTR 5%-10% | 111 | 6 | 6.7 | 0.1 | 6.5 to 7.0 | 3.2 | 1.8 | 1.0 to 9.5 | .05 |
| 4 IBTR > 10% | 33 | 3 | 12.5 | 0.5 | 11.4 to 13.6 | 8.7 | 6.2 | 2.1 to 32.5 | .5 |
| Overall | 664 | 22 | 4.0 | 1.0 | 3.8 to 4.2 | 2.8 | 0.8 | 1.6 to 4.7 | .1 |
Abbreviations: IBTR, ipsilateral breast tumor recurrence; SE, standard error.