Table 2.
Net risk of iIBC in DCIS patients without locoregional treatment, based on SEER (1992–2014)*
| Risk measure | All (n = 1286) | Tumor grade |
ER status |
Tumor size |
Age at diagnosis |
||||
|---|---|---|---|---|---|---|---|---|---|
| Nonhigh (n = 547) | High | Positive | Negative | ≤1 cm | >1 cm | <55 y | ≥55 y | ||
| (n = 244) | (n = 407) | (n = 64) | (n = 266) | (n = 187) | (n = 463) | (n = 823) | |||
| Net risk of iIBC, % (95% CI) | |||||||||
| 5 y | 7.3 | 6.7 | 10.0 | 6.5 | 10.7 | 5.1 | 10.7 | 8.7 | 6.5 |
| (5.8 to 9.1) | (4.6 to 9.8) | (6.4 to 15.3) | (4.1 to 10.2) | (4.5 to 24.3) | (2.8 to 9.1) | (6.3 to 18.0) | (6.2 to 12.0) | (4.8 to 8.7) | |
| 10 y | 12.1 | 12.2 | 17.6 | NA | NA | 10.9 | 14.2 | 13.6 | 11.3 |
| (10.0 to 14.7) | (8.6 to 17.1) | (12.1 to 25.2) | (6.8 to 17.3) | (8.4 to 23.4) | (10.2 to 18.0) | (8.6 to 14.7) | |||
| 15 y | 14.0 | NA | NA | NA | NA | 12.5 | NA | 15.2 | NA |
| (11.4 to 17.2) | (7.8 to 19.8) | (11.4 to 20.3) | |||||||
| Cox Proportional Hazard Models | |||||||||
| Univariate HR (95% CI) | — | 1.00 (Ref) | 1.56 | 1.00 (Ref) | 1.65 | 1.00 (Ref) | 1.67 | 0.99† | |
| (0.96 to 2.55) | (0.67 to 4.06) | (0.88 to 3.17) | (0.98 to 1.01) | ||||||
| Multivariat HR (95% CI) | — | 1.00 (Ref) | 1.44 | 1.00 (Ref) | 1.40 | 1.00 (Ref) | 1.62 | 0.99† | |
| (0.87 to 2.37) | (0.56 to 3.50) | (0.84 to 3.10) | (0.98 to 1.01) | ||||||
*
For risk estimates and HRs in patients with unknown tumor features, see Supplementary Table 1 (available online). CI = confidence interval; DCIS = ductal carcinoma in situ; HR = hazard ratio; iIBC = ipsilateral invasive breast cancer; NA = estimates not reported when less than 10% of initial patients remain at risk; Ref = reference factor; SEER = US National Cancer Institute’s Surveillance, Epidemiology, and End Results program.
†
Age as continuous variable (years) in Cox models.