Abstract P1-16-04: Intraoperative ultrasound-guided breast conserving surgery for palpable and nonpalpable breast cancer

Abstract Objective: Intraoperative ultrasound guided (IUG) breast conserving surgery (BCS) is being increasingly embraced by breast surgeons worldwide. Real-time sonographic localization provides tumor free margins with low excision volumes and decreases rate of reoperations. We aimed to compare the efficacy of IUG-BCS for palpable and nonpalpable breast cancer with respect to margin status, re-excision rate, tumor free tissue sacrifice and cost-time analysis. The relationship between intraoperative assessment of gross macroscopic and ultrasonographic margins and frozen section results, were also analyzed. Methods: Between 2011 and 2014, IUG-BCS were performed to 208 patients with the diagnosis of in situ or invasive carcinoma. Intraoperative localization protocol includes ultrasound visualization of the lesion, tumor margin determination, and image confirmation of specimen and tumor bed. Sonographic and macroscopic assessment of the surgical margins by surgeon was followed by frozen section analysis of each margin. Moreover, cavity shaved margins from tumor bed were also obtained for permanent section analysis. Results: Of the 208 patients, 89 (42.8%) had palpable and 119 (57.2 %) had nonpalpable tumors. The sensitivity of intraoperative ultrasound localization was 100% (208/208 cases). Patients were on average 55 years old (range, 25-92). There was no difference with respect to patient characteristics including age, menopausal status, personal-family history, oral contraceptive usage, body mass index and tumor localization. Mean tumor size was 1.14 cm for nonpalpable and 2.87 cm. for palpable tumors. Negative margins were achieved in 92.43 % of nonpalpable (110/119) and 91.01% (81/89) of palpable lesions at the initial procedure verified by frozen section analysis. The involved margins were correctly identified by the surgeon via specimen sonography in 95.4% of the cases (15/17). According to frozen section analysis of the 1248 ultrasonographically clear margins, re-excisions were required for 16 margins of palpable and 14 margins of nonpalpable tumors. The overall positive margin rate determined by frozen section analysis was 2.4% (30/1248), with the majority of these patients (12/17) proved to have significant degrees of pure DCIS or mixed invasive ductal with DCIS at final histopathologic evaluation. Three patients (2.5%) with nonpalpable and two patients (2.24%) with palpable tumors required a second operation for either determination of close margins or multifocality at cavity shaved margins, without residual cancer on pathological examination of the reoperative specimens. IUG-BCS resulted in smaller excision volumes in nonpalpable cancers due to their size, as expected. However, calculated resection ratio was found to be similar for both groups. A cost and time analysis determined nothing significant between groups. Conclusion: IUG-BCS is an invaluable and effective modality for both palpable and nonpalpable breast cancer in obtaining clear surgical margins with optimum resection volumes and reducing re-operations. Furthermore, frozen section analysis of the specimen margins together with shaving cavity margins of the tumor bed for permanent analysis could be a feasible method for minimizing the requirement for reoperations. Citation Format: Guldeniz Karadeniz Cakmak, Ali U Emre, Oge Tascilar, Burak Bahadir, Selcuk Ozkan. Intraoperative ultrasound-guided breast conserving surgery for palpable and nonpalpable breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-16-04.