Intraoperative Frozen Section Versus Intraoperative Gross Examination in the Assessment of Myometrial Invasion in Clinical Stage I Endometrial Cancer

Abstract

Objective: To evaluate the accuracy of frozen section and gross examination in assessing myometrial invasion in endometrial cancer with respect to definitive histological examination.
Methods: A retrospective study of women who underwent surgical treatment for clinical stage I endometrial cancer at the Pamela Youde Nethersole Eastern Hospital between 1 July 2003 and 30 June 2013 was conducted. The women underwent intraoperative gross examination or frozen section for assessment of myometrial invasion. Deep myometrial invasion was defined as involvement of ≥50% of the thickness of the myometrium. The final histopathology was considered the reference standard. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for both modalities were analysed.
Results: Of 115 women included in the study, 49 had gross examination and 66 had frozen section. Gross
examination correctly identified (accuracy) the depth of myometrial invasion in 67.3% of cases with sensitivity, specificity, and positive and negative predictive values of 33.4%, 78.4%, 33.3%, and 78.4%, respectively. Frozen section correctly identified (accuracy) 95.5% of cases with sensitivity, specificity, and positive and negative predictive values of 92.3%, 96.2%, 85.7%, and 98.1%, respectively.
Conclusion: Frozen section appeared to be more effective than gross examination in assessing myometrial invasion and hence should be preferred as a basis for selective lymphadenectomy for clinical stage I endometrial cancer.