Intraoperative radiation therapy in early-stage breast cancer: Presence of lobular features is not associated with increased rate of requiring additional therapy

Background: There is a paucity of data regarding the application of IORT to the treatment of carcinomas with lobular features. Methods: This study includes women with invasive breast cancer who underwent breast conservation in combination with IORT from February 2011 to October 2016. Patients whose final pathology did not satisfy inclusion criteria or had inadequate margins were recommended to undergo additional therapy (AT) with WBRT as well as re-excision of inadequate margins. Results: 243 invasive breast cancers were treated with IORT. The lobular features (LF) group comprised 62 patients and the invasive ductal carcinoma (IDCA) group consisted of 172 patients. Rate of AT was similar between groups (LF 19 patients, 30.6%, vs IDCA 56 patients, 32.6%, p = 0.87) groups. Lobular histology was not associated with a need for AT. Local recurrence rate for the cohort was 1.2% with a median follow up of 46 months. There was no difference in recurrence or survival after 46 months of follow-up. Conclusions: IORT is an effective treatment option for well-selected patients with early breast cancer and can be considered for patients with lobular histology.