866 Effect of circumferential tumor cavity shaving in reducing the rate of mastectomy

Introduction/Background* Breast-Conserving Surgery (BCS) is considered a standard of care for women with early-stage breast cancer. Achieving adequate margins excision crucial component surgery. In our department, we routinely assess circumferential tumor cavity shaving (CTCS) status using frozen section analysis. We sought to determine the effect CTCS on reducing rate mastectomy no residual disease. Methodology conducted retrospective review prospectively maintained database patients who underwent primary BCS stage 0-III cancer between January 2015 and December 2019 in Salah Azaiez Institute Oncology, Tunis, Tunisia. identified 142 conservative surgery positive histological examination. Complementary treatment consisting was performed all patients. Result(s)* The mean age 50. average size 28 mm. bifocal 20%. 55% tumors were Grade II SBR. Invasive ductal carcinoma (IDC) most common subtype (74%). It associated 79% cases situ (DCIS). For CTCS, 60% DCIS, 40% invasive carcinoma. A complementary indicated detected remaining mammary gland 60.4% cases, out which 39% DCIS. Chi-square test found that presence DCIS lymphovascular invasion, not related or in-situ disease (p<0.05). Conclusion* can help detect multifocal diseases. Nevertheless, need find way avoid gland.