Table 2.
Second breast cancer events according to initial treatment among 1,252 DCIS cases from the Vermont Breast Cancer Surveillance System.
| All (N=1,252) |
Mastectomy (N=201) |
BCS alone (N=327) |
BCS + RT (N=318) |
BCS + RT and ET (N=276) |
BCS + ET (N=130) |
|
|---|---|---|---|---|---|---|
| Median follow-up (years) | 7.8 | 8.1 | 6.2 | 7.8 | 8.5 | 7.9 |
| Any second event, N (rate per 100 person-years) | 192 (2.0) | 24 (1.5) | 72 (3.6) | 57 (2.3) | 26 (1.1) | 13 (1.3) |
| Ipsilateral event, N | 114 | 6 | 55 | 29 | 14 | 10 |
| Contralateral event, N | 69 | 17 | 15 | 25 | 10 | 2 |
| Bilateral event, N | 7 | 0 | 2 | 2 | 2 | 1 |
| Distant events, N | 2 | 1 | 0 | 1 | 0 | 0 |
| Invasive event, N | 126 | 16 | 45 | 40 | 15 | 10 |
| DCIS event, N | 66 | 8 | 27 | 17 | 11 | 3 |
| Ipsilateral invasive, N | 74 | 6 | 33 | 19 | 9 | 7 |
| Ipsilateral DCIS, N | 40 | 0 | 22 | 10 | 5 | 3 |
| Contralateral Invasive, N | 45 | 9 | 11 | 18 | 5 | 2 |
| Contralateral DCIS, N | 24 | 8 | 4 | 7 | 5 | 0 |
| Bilateral invasive, Na | 5 | 0 | 1 | 2 | 1 | 1 |
| Bilateral DCIS, Na | 2 | 0 | 1 | 0 | 1 | 0 |
Abbreviations: BCS, breast conserving surgery. DCIS, ductal carcinoma in situ; ET, endocrine therapy; RT, radiation therapy.
a
A bilateral diagnosis was counted as invasive if either or both breasts had an invasive second event and as DCIS if both breasts had DCIS.