Robustness of a Newly Proposed Risk Schema for Lymphatic Dissemination in Endometrioid Endometrial Cancer

Authors

Danielle M. Greer, Aurora University of Wisconsin Medical Group; Center for Urban Population HealthFollow
Jessica J.F. Kram, Aurora University of Wisconsin Medical Group; Center for Urban Population HealthFollow
Callie M. Cox Bauer, Department of Obstetrics and Gynecology, Brook Army Medical CenterFollow
Scott A. Kamelle, Aurora Gynecologic OncologyFollow

Publication Date

11-6-2017

Keywords

lymph node, endometrioid endometrial cancer, risk stratification, surgical management, metastasis

Abstract

Background: Surgical management for endometrioid endometrial cancer (EEC) includes complete lymph node dissection for all patients at risk of lymphatic dissemination. The standard risk schema, defined by Mayo Clinic, identifies low-risk patients as those with grade 1/2 EEC, myometrial invasion (MI) ≤ 50%, and tumor diameter (TD) ≤ 2 cm. We recently proposed (and published) a risk schema containing modified forms of grade, MI and TD that suggests a significant decrease in false-negative rate and need for lymphadenectomy in low-risk women.

Purpose: Evaluate robustness of our proposed schema for lymphatic dissemination risk stratification in a subsequent EEC patient cohort.

Methods: We retrospectively applied the proposed schema to patients diagnosed with stage I–III EEC during 2014–2015 who underwent pelvic and/or para-aortic lymph node removal. Cancer Registry data were confirmed via chart review. Consistent with the cohort studied during model development, the validation cohort included non-Hispanic white or black patients with complete data describing TD (≤ 50 mm or > 50 mm), MI (≤ 33%, > 33% to ≤ 66%, or > 66%) and grade (1 or 2–3).

Results: In the validation cohort, 29 (11.7%) of the 247 EEC patients were node-positive (vs 9.2% of 737 patients in the development cohort). Risk stratification using the proposed schema produced similar false-positive rates during model development (57.2%) and validation (54.6%), both 20% lower than when using the standard schema (76.2% and 74.3%, respectively). False-negative rates, however, were noticeably different between development and validation cohorts using both the proposed (0% and 13.8%) and standard (1.47% and 6.90%) schemas, suggesting a shift toward low-risk classification in node-positive patients of the validation cohort.

Conclusion: Application of the proposed risk stratification schema to an alternative patient cohort verified the utility of modified risk criteria, including TD with 50-mm cutoff, for identifying low-risk EEC patients who may not require node evaluation. However, in the validation cohort, greater prevalence of lymph node metastasis and low-risk classification of node-positive patients was observed. Discrepancy between cohorts is likely due to greater utilization of sentinel lymph node mapping during the validation period, allowing for increased detection of low-volume metastases. Continued model development and validation is needed, especially to account for the increased sensitivity of new technologies.

Recommended Citation

Greer DM, Kram JJ, Cox Bauer CM, Kamelle SA. Robustness of a newly proposed risk schema for lymphatic dissemination in endometrioid endometrial cancer. J Patient Cent Res Rev. 2017;4:262.