title: Preoperative identification of a low-risk group for lymph node metastasis in endometrial cancer: a Korean gynecologic oncology group study.
abstract: OBJECTIVE
  The aim of this study was to develop a preoperative risk prediction model for lymph node metastasis in patients with endometrial cancer and to identify a low-risk group before surgery.
  
  
  METHODS
  The medical records of 360 patients with endometrial cancer who underwent surgical staging were collected from four institutions and were retrospectively reviewed. By using serum CA-125 levels, preoperative biopsy data, and magnetic resonance imaging (MRI) data, a multivariate logistic model was created. Patients whose predicted probability was less than 4% were defined as low risk. The developed model was externally validated in 180 patients from two independent institutions.
  
  
  RESULTS
  Serum CA-125 levels and three MRI parameters (deep myometrial invasion, lymph node enlargement, and extension beyond uterine corpus) were found to be independent risk factors for nodal metastasis. The model classified 53% of patients as part of a low-risk group, and the false negative rate was 1.7%. In the validation cohort, the model classified 43% of patients as low-risk, and the false negative rate was 1.4%. The model showed good discrimination (area under the receiver operator characteristic curve = 0.85) and was calibrated well. The negative likelihood ratio of our low-risk criteria was 0.11 (95% CI, 0.04 to 0.29), which was equivalent to the false-negative rate of 1.3% (95% CI, 0.5% to 3.3%) at the assumed prevalence of nodal metastasis of 10%.
  
  
  CONCLUSIONS
  Using serum CA-125 and MRI as criteria resulted in the accurate identification of a low-risk group for lymph node metastasis among patients with endometrial cancer.
authors.affiliation: Center for Uterine Cancer, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Sokbom
authors.initials: S
authors.lastname: Kang
authors.forename: Woo Dae
authors.initials: WD
authors.lastname: Kang
authors.forename: Hyun Hoon
authors.initials: HH
authors.lastname: Chung
authors.forename: Dae Hoon
authors.initials: DH
authors.lastname: Jeong
authors.forename: Sang-Soo
authors.initials: SS
authors.lastname: Seo
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Lee
authors.forename: Jae Weon
authors.initials: JW
authors.lastname: Kim
authors.forename: Seok-Mo
authors.initials: SM
authors.lastname: Kim
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Park
authors.forename: Ki Tae
authors.initials: KT
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001707:Biopsy, Needle; D018394:CA-125 Antigen / Q000097:blood*; D015331:Cohort Studies; D016001:Confidence Intervals; D016889:Endometrial Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D007044:Hysterectomy / Q000379:methods; D007150:Immunohistochemistry; D007723:Korea; D016015:Logistic Models; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D018394:CA-125 Antigen