Identifying patients at risk of compromised margins following breast conservation for lobular carcinoma

Background The association of invasive lobular carcinoma with high rates of compromised margins in breast conservation makes choice of operation for these patients difficult. We sought to identify patients at risk of compromised margins following breast conservation surgery. Methods We reviewed all patients with invasive lobular and invasive ductal carcinoma over a 5-year period (1999–2004). The imaging, pathology and surgical details of patients with invasive lobular carcinoma undergoing breast conservation were analyzed. Results A total of 991 patients with invasive ductal carcinoma and 150 patients with invasive lobular carcinoma were identified. Lobular carcinomas had a compromised margin rate of 49% (n = 38/77) in breast conservation compared to 24% (n = 143/588) of ductal carcinomas (P < .0001). Mammographic size (P = .017), pathological size (P = .01), age (P = .03), multifocality (P < .0001), and lymphovascular invasion (P = .015) were significantly associated with compromised margins. Conclusion Invasive lobular carcinoma has a 49% rate of compromised margins following breast conservation. Mammographic size greater than 1.5 cm and young age were preoperative factors predictive of compromised margins.