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