Table 3.
Invasive IBE Rates for Clinically Relevant Subsets of Patients
| Variable | No. of Patients | 5 Years |
10 Years |
12 Years |
P | |||
|---|---|---|---|---|---|---|---|---|
| % | 95% CI | % | 95% CI | % | 95% CI | |||
| Cohort 1 | 561 | 2.7 | 1.3 to 4.1 | 6.4 | 4.2 to 8.6 | 7.5 | 5.1 to 10.0 | .08 |
| Cohort 2 | 104 | 5.3 | 0.8 to 9.7 | 13.4 | 5.9 to 20.9 | 13.4 | 5.9 to 20.9 | |
| Age, years | ||||||||
| ≤ 49 | 131 | 4.8 | 1.1 to 8.6 | 8.5 | 3.4 to 13.5 | 9.6 | 4.1 to 15.0 | .43 |
| 50-69 | 370 | 3.4 | 1.5 to 5.4 | 7.6 | 4.7 to 10.5 | 8.8 | 5.7 to 12.0 | |
| ≥ 70 | 164 | 0.7 | 0 to 2.1 | 6.2 | 1.7 to 10.8 | 6.2 | 1.7 to 10.8 | |
| Minimum negative margin width, mm | ||||||||
| < 5 | 235 | 2.8 | 0.6 to 4.9 | 8.1 | 4.3 to 11.9 | 8.1 | 4.3 to 11.9 | .64 |
| 5-9 | 286 | 3.4 | 1.2 to 5.5 | 7.8 | 4.4 to 11.3 | 9.6 | 5.7 to 13.4 | |
| ≥ 10 | 144 | 3.1 | 0.1 to 6.0 | 5.6 | 1.6 to 9.6 | 6.7 | 2.2 to 11.2 | |
| Tumor size, mm* | ||||||||
| ≤ 5 | 254 | 2.5 | 0.5 to 4.5 | 6.3 | 3.1 to 9.5 | 6.3 | 3.1 to 9.5 | .40 |
| 6-10 | 292 | 2.9 | 0.9 to 4.9 | 8.5 | 5.0 to 12.0 | 10.3 | 6.3 to 14.3 | |
| > 10 | 119 | 4.8 | 0.7 to 8.8 | 7.2 | 2.0 to 12.4 | 8.7 | 2.8 to 14.6 | |
| CAP grade† | ||||||||
| Low | 63 | 1.8 | 0 to 5.3 | 5.5 | 0 to 11.6 | 5.5 | 0 to 11.6 | .19 |
| Intermediate | 268 | 2.0 | 0.3 to 3.8 | 5.4 | 2.4 to 8.4 | 6.7 | 3.2 to 10.1 | |
| High | 169 | 4.5 | 1.2 to 7.7 | 11.7 | 6.4 to 17.0 | 11.7 | 6.4 to 17.0 | |
Abbreviations: CAP, College of American Pathologists; IBE, ipsilateral breast event.
*
Tumor size was based on central pathology review, when this information was available. Results are similar for tumor size on the basis of institutional pathology assessment at enrollment onto the study (P = .40; data not shown).
†
Restricted to the subset of 500 cases for which a central pathology review was performed using current CAP guidelines.