Frozen section underestimates the need for surgical staging in endometrial cancer patients.

OBJECTIVE: To compare the risk status for lymph nodal metastasis at frozen section in endometrial cancer by applying a model based on tumor grade and myometrial involvement. STUDY DESIGN: A retrospective analysis was performed on 174 early-stage endometrial cancer patients on whom an intraoperative frozen section was requested. Patients were retrospectively divided into low, intermediate, and high risk for lymph nodal involvement based on tumor grade and myometrial invasion based on Gynecologic Oncology Group 33 data. Concordance of risk status at frozen and permanent sections was performed. RESULTS: Risk status at frozen and permanent sections were highly correlated (P <0.01). Agreement between frozen and permanent sections was substantial (kappa = 0.625). In 16% of the cases, frozen section underestimated the risk when compared with permanent section. CONCLUSION: Relying on intraoperative frozen section of the uterus to assess risk status for lymph nodal involvement in early-stage endometrial cancer patients leads to suboptimal management in a substantial number of cases.