Needle core biopsy characteristics identify patients at risk of compromised margins in breast conservation surgery

Selection of patients for breast-conserving surgery relies on inexact parameters such as the preoperative estimation of lesion size. This study investigates the value of needle core biopsy findings, in particular, the relative quantity of DCIS, in improving patient selection for breast conservation. Patients undergoing breast-conserving surgery for invasive ductal carcinoma from 1999 to 2004 were identified. Only patients who had a preoperative diagnosis of carcinoma (DCIS and invasive) on core biopsy were included. All core biopsies were reviewed by a breast histopathologist to document the quantity and characteristics of the DCIS component. Of a total of 281 patients, 46% ( n =129) had invasive disease on core biopsy (group 1) and 54% ( n =152) had either invasive disease with an accompanying DCIS component or DCIS only on core biopsy (group 2). The compromised margin rate for group 1 was 23% compared to 39% for group 2 ( P =0.004). The rate of compromised margins increased progressively as the core biopsy DCIS component increased until a rate of 75% ( n =18/24) was reached in patients with DCIS only on core biopsy. In patients with a DCIS component on core biopsy, the presence of necrosis ( P =0.002), solid type architecture ( P =0.008), high grade DCIS ( P =0.007), calcification ( P =0.003), and the relative proportion of DCIS present ( P