title: A validation study of new risk grouping criteria for postoperative treatment in stage IB cervical cancers without high-risk factors: rethinking the Gynecologic Oncology Group criteria.
abstract: OBJECTIVE
  The aim of this study was to verify whether the Gynecologic Oncology Group (GOG) criteria are valid in a different cohort of patients and to investigate simplified new criteria tailoring adjuvant radiation therapy in patients with intermediate-risk factors after radical hysterectomy.
  
  
  METHODS
  We analyzed the data of 332 patients with FIGO stage IB cervical cancer who underwent radical hysterectomy between 1994 and 2007. Two hundred and twenty-five patients without high-risk factors (lymph node metastasis, parametrial invasion, or positive surgical margins) were identified and were classified into low-risk and high-risk groups according to the GOG criteria and new criteria based on combinations of intermediate-risk factors (large tumor size, deep stromal invasion, lymph-vascular space invasion). We evaluated the prognostic significance of both criteria.
  
  
  RESULTS
  We identified 140 low-risk patients and 85 high-risk patients in the application of the GOG criteria. Low-risk patients had significantly better disease-free survival (DFS) (P=0.001) and overall survival (OS) (P=0.013) than high-risk patients. There were 145 low-risk patients and 80 high-risk patients on applying the new criteria. Low-risk patients had significantly better DFS (P=0.001) and OS (P=0.013) than high-risk patients. The receiver operating characteristic (ROC) curves showed that both criteria had similar performance for predicting which patients would have help from adjuvant therapy.
  
  
  CONCLUSIONS
  This study demonstrated that the GOG criteria were still valid in the different population, the simplified new criteria were convenient to apply in practice, and the performance of the new criteria was as good as the GOGs.
authors.affiliation: Department of Obstetrics and Gynecology, Ajou University School of Medicine, Suwon, Gyunggi-do 442-721, Republic of Korea.
authors.forename: Suk-Joon
authors.initials: SJ
authors.lastname: Chang
authors.forename: Woo Young
authors.initials: WY
authors.lastname: Kim
authors.forename: Seung-Chul
authors.initials: SC
authors.lastname: Yoo
authors.forename: Jong-Hyuck
authors.initials: JH
authors.lastname: Yoon
authors.forename: Mison
authors.initials: M
authors.lastname: Chun
authors.forename: Ki-Hong
authors.initials: KH
authors.lastname: Chang
authors.forename: Hee-Sug
authors.initials: HS
authors.lastname: Ryu
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008875:Middle Aged; D009367:Neoplasm Staging; D011182:Postoperative Care / Q000379:methods*; D011379:Prognosis; D012372:ROC Curve; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*