Table 2.

Positive margin status and reexcision lumpectomy procedures

Variable	Treatment group		Reduction	p
	Device (n = 298)	Control (n = 298)
Positive margins after initial surgery
All patients	92/298 (30.9 %)	124/298 (41.6 %)	26 %	0.008
At skin or fascia	15/298 (5.0 %)	18/298 (6.0 %)		0.72
Candidates for reexcision	77/298 (25.8 %)	106/298 (35.9 %)	27 %	0.013
Due to positive margin on main specimens	47/298 (15.8 %)	97/298 (32.9 %)	52 %	<0.001
Due to positive margin on shavings	30/298 (10.1 %)	9/298 (3.0 %)		<0.001
Reexcision lumpectomy procedures	59/298 (19.8 %)	77/298 (25.8 %)	23 %	0.097; 0.018a
Due to positive margin on main specimens	33/298 (10.0 %)	62/298 (20.8 %)	47 %	0.002
Due to positive margin on shavings	19/298 (7.4 %)	4/298 (1.3 %)		0.002
Due to close margins or other considerations	7/298 (2.3 %)	11/298 (3.7 %)		0.47

^aAccounting for the difference between arms in the number of main lumpectomy specimens with positive margins (Fig. 2, phase I)