Accuracy of frozen-section examination for myometrial invasion and grade in endometrial cancer

Abstract

Objective: To evaluate the accuracy of frozen section (FS) analysis in endometrial cancer.

Study design: The medical records of 816 patients with stage IA-IVB endometrial carcinoma were evaluated. Concordance of the frozen section examination and postoperative evaluation in terms of the depth of myometrial invasion (MI) and grade was assessed.

Results: The mean age of the patients was 58.1 years. Postoperative pathology revealed endometrioid type tumor in 756 patients. Concordance of intraoperative and postoperative pathology results in terms of grade was 89%. This rate was 96.8% for grade 1, 86% for grade 2 and 91.3% for grade 3 tumors. Sensitivity and specificity of intraoperative evaluation for grade 1, grade 2 and grade 3 were 89.3%, 91.2%, 77.8% and 93.1%, 96.1%, 99.5%, respectively. Intraoperative and postoperative determination of MI was consistent in 85.4% of patients. MI was assessed accurately in 78.5% of patients with no involvement of myometrium and in 90.5% and 95.3% of patients with myometrial invasion <1/2 and ≥1/2, respectively. Sensitivity and specificity of FS in prediction of the absence of MI, MI<1/2 and ≥1/2 were 60%, 91.5%, 88.8% and 96.6%, 88.3%, 98.3%, respectively. The accuracy of myometrial invasion was affected by the postoperative grade. Concordance was higher in grade 2 and 3 than grade 1 tumors.

Conclusion: The accuracy of intraoperative pathologic evaluation in endometrial cancer is reasonably high. For that reason, results of the intraoperative pathologic examination should be taken into consideration primarily in the management for lymphadenectomy.