TABLE 3.
Outcome data in the pre- and post-guideline study periods
| Factor/Outcome | Overall | Pre-Study Period (n = 504) | Post-Study Period (n = 701) | p-value |
|---|---|---|---|---|
| Margin width, invasive* | 0.797 | |||
| - Negative (> 1 mm) | 1063 (88.2) | 441 (87.5) | 622 (88.7) | |
| - Close (≤ 1 mm) | 83 (6.9) | 37 (7.3) | 46 (6.6) | |
| - Positive | 59 (4.9) | 26 (5.2) | 33 (4.7) | |
| Margin width, DCIS† | 0.086 | |||
| - Negative (> 1 mm) | 954 (79.3) | 384 (76.5) | 570 (81.3) | |
| - Close (≤ 1 mm) | 196 (16.3) | 90 (17.9) | 106 (15.1) | |
| - Positive | 53 (4.4) | 28 (5.6) | 25 (3.6) | |
| Number of re-excisions | 0.017 | |||
| - 0 | 991 (82.2) | 396 (78.6) | 595 (84.9) | |
| - 1 | 195 (16.2) | 97 (19.2) | 98 (14) | |
| - 2 | 16 (1.3) | 10 (2) | 6 (0.9) | |
| - ≥ 3 | 3 (0.2) | 1 (0.2) | 2 (0.3) | |
| Mastectomy†† (performed) | 8 (0.7) | 2 (0.4) | 6 (0.9) | 0.480 |
*
Width of closest margin, invasive component only
†
Width of closest margin, DCIS component only
††
Mastectomy performed following attempted breast-conserving surgery
DCIS, ductal carcinoma in situ