Accuracy of frozen section in management and prediction of lymph node metastasis in endometrial carcinoma

Objective: This study aimed to investigate clinical factors affecting the concordance between frozen section (FS) and paraffin section (PS) findings in endometrial cancer, and evaluate the role of FS in predicting lymph node (LN) metastases. Methods: Tumor grade and depth of myometrial invasion based on FS and PS findings were compared in 376 patients. Clinical factors affecting the accuracy of FS in predicting LN metastasis were evaluated. Overall survival was compared between patients who underwent lymphadenectomy and those who did not. Results: Overall concordance of tumor grade was 78.6% (147/187). Later age at menopause (p = 0.011) and a lower systolic/diastolic ratio of endometrial blood flow (p = 0.015) were associated with high concordance between FS and PS for tumor grade. Overall concordance for the depth of myometrial invasion was 97.8% (178/182). There was greater concordance between FS and PS for myometrial invasion in patients with postmenopausal bleeding (p = 0.018) and lower abdominal pain (p = 0.013). G1 and G2 + no myometrial invasion predicted no metastasis; G1 + <1/2 myometrial invasion predicted a 2.4% risk of both pelvic LN and para-aortic LN metastasis. G2 +