The accuracy and clinical impact of intraoperative frozen section in determining the extent of surgical intervention in patients with early stage endometrial cancer

The aim of this study was to compare intraoperative frozen section (FS) with the final pathology (FP), and determine its clinical impact in clinically apparent early stage endometrial cancer (EC) at the American University of Beirut Medical Center (AUBMC). Data for patients 18 years or older, with clinically apparent early stage, grade 1 or 2, endometrioid EC, who underwent hysterectomy +/- lymph node dissection (LND) at AUBMC between January 1(st) 1996 and June 30(th) 2016 were retrospectively reviewed. 70 patients were included. The overall concordance between FS and FP was 92.3% for histological subtype, 77% for tumour grade, 82% for Myometrial invasion (MI) and 100% for tumour size. At a median follow up of 30 months, 8 recurrences (11.4%) were noted, with a 5-year PFS and OS of 76 and 84% respectively, with a trend towards lower recurrence and improved survival in patients who underwent FS or LND.Impact statement What is already known on this subject? Hysterectomy and bilateral salpingo-oophorectomy is the standard surgery for stage I endometrial cancer (EC). Intraoperative frozen section (FS) facilitates the decision on performing lymph node dissection (LND). However, its accuracy and clinical impact have been questioned. What do the results of this study add? Our objective is to compare FS with the final pathology (FP), and determine its clinical impact in clinically apparent early stage EC at the American University of Beirut Medical Center (AUBMC). There is a lack of standardisation regarding FS use and reporting at AUBMC. What are the implications of these findings for clinical practice and/or further research? The strong correlation between FS and FP can serve as a tool to guide decision to perform LND in patients with apparent early stage disease, where use of sentinel LN biopsy technique is not available.