An ultrasound-based risk model to predict lymph node metastases before surgery in women with endometrial cancer: a model development study.
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
OBJECTIVES: To develop a pre-operative risk model using endometrial biopsy results, clinical and ultrasound variables to predict the individual risk of lymph node metastases in women with endometrial cancer. METHODS: A mixed effects logistic regression model was developed on 1501 prospectively included women with endometrial cancer subjected to transvaginal ultrasound examination before surgery. Missing data, including missing lymph node status, was imputed. Discrimination, calibration and clinical utility were evaluated using leave-center-out cross-validation. The predictive performance was compared with risk classification from endometrial biopsy alone (high-risk = endometrioid cancer grade 3/non-endometrioid cancer) or combined endometrial biopsy and ultrasound (high-risk = endometrioid cancer grade 3/non-endometrioid cancer/deep myometrial invasion/cervical stromal invasion/extrauterine spread). RESULTS: Lymphadenectomy was performed in 691 women, of which 127 had lymph node metastases. The model included the predictors age, duration of abnormal bleeding, endometrial biopsy result, tumor extension and tumor size according to ultrasound and "undefined tumor with an unmeasurable endometrium". The model's AUC was 0.73 (95% CI 0.68 to 0.78), calibration slope 1.06 (95% CI 0.79 to 1.34) and calibration intercept 0.06 (95% CI 0.15 to 0.27). Using risk thresholds for lymph node metastases 5% vs. 20% the model had sensitivity 98% vs. 48% and specificity 11% vs. 80%. The model had higher sensitivity and specificity than high-risk according to endometrial biopsy alone (50% vs. 35% and 80% vs. 77%) or combined endometrial biopsy and ultrasound (80% vs. 75% and 53% vs. 52%). The model's clinical utility was higher than that of endometrial biopsy alone or combined endometrial biopsy and ultrasound at any given risk threshold. CONCLUSIONS: Based on endometrial biopsy results, clinical and ultrasound characteristics, the individual risk of lymph node metastases in women with endometrial cancer can be reliably estimated before surgery. The model is superior to risk classification by endometrial biopsy alone or in combination with ultrasound. This article is protected by copyright. All rights reserved.
Date Issued
2020-09-01
Date Acceptance
2019-12-07
Citation
Ultrasound in Obstetrics and Gynecology, 2020, 56 (3), pp.443-452
ISSN
0960-7692
Publisher
Wiley
Start Page
443
End Page
452
Journal / Book Title
Ultrasound in Obstetrics and Gynecology
Volume
56
Issue
3
Copyright Statement
© 2019 ISUOG. Published by John Wiley & Sons Ltd. . This is the peer reviewed version of the following article, which has been published in final form at https://obgyn.onlinelibrary.wiley.com/doi/full/10.1002/uog.21950. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/31840873
Subjects
decision support model
diagnostic imaging
endometrial neoplasm
lymphatic metastasis
neoplasm staging
ultrasonography
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2019-12-16