A prospective assessment of the reliability of frozen section to direct intraoperative decision making in endometrial cancer

Objective. To determine the reliability of intraoperative frozen sections (IFSs) for surgical staging of endometrial cancer (EC). Methods. Data were collected prospectively on 784 consecutive patients with EC who were undergoing a hysterectomy at our institution from January 1, 2004, to December 31, 2008. The need for surgical staging was decided through IFS using 4 variables: tumor size, histologic grade, histologic subtype, and depth of myometrial invasion (MI). The IFS results were compared with the permanent paraffin sections (PSs) to assess for discordances. Results. In 30 of the 784 cases (4%), the PS pathology report was amended with discordant results. In addition, a definitive diagnosis of the 4 parameters was deferred to PS in 53 cases (7%), of which 30 (4%) were concordant and 23 (3%) were discordant. IFS-related deviations from the prescribed surgical algorithm occurred in 10 cases (1.3%; 95% confidence interval, 0.6%-2.3%). Of these 10 cases, 3 were amendments after PS review and 7 were IFS deferrals for definitive PS interpretation. Conclusions. Clinically significant discordance between IFS and PS occurred in only 1.3% of cases. Despite skepticism expressed in the medical literature, IFS provides highly reliable data to guide intraoperative treatment decisions at institutions with sufficient pathologic expertise. (C) 2012 Elsevier Inc. All rights reserved.