title: Incorporation of postoperative CT data into clinical models to predict 5-year overall and recurrence free survival after primary cytoreductive surgery for advanced ovarian cancer.
abstract: OBJECTIVE
  The use of multivariable clinical models to assess postoperative prognosis in ovarian cancer increased. All published models incorporate surgical debulking. However, postoperative CT can detect residual disease (CT-RD) in 40% of optimally resected patients. The aim of our study was to investigate the added value of incorporating CT-RD evaluation into clinical models for assessment of overall survival (OS) and progression free survival (PFS) in patients after primary cytoreductive surgery (PCS).
  
  
  METHODS
  212 women with PCS for advanced ovarian cancer between 01/1997 and 12/2011, and a contrast enhanced abdominal CT 1-7 weeks after surgery were included in this IRB approved retrospective study. Two radiologists blinded to clinical data, evaluated all CT for the presence of CT-RD, and Cohen's kappa assessed agreement. Cox proportional hazards regression with stepwise selection was used to develop OS and PFS models, with CT-RD incorporated afterwards. Model fit was assessed with bootstrapped Concordance Probability Estimates (CPE), accounting for over-fitting bias by correcting the initial estimate after repeated subsampling.
  
  
  RESULTS
  Readers agreed on the majority of cases (179/212, k=0.68). For OS and PFS, CT-RD was significant after adjusting for clinical factors with a CPE 0.663 (p=0.0264) and 0.649 (p=0.0008). CT-RD was detected in 37% of patients assessed as optimally debulked (RD<1cm) and increased the risk of death (HR: 1.58, 95% CI: 1.06-2.37%).
  
  
  CONCLUSIONS
  CT-RD is a significant predictor after adjusting for clinical factors for both OS and PFS. Incorporating CT-RD into the clinical model improved the prediction of OS and PFS in patients after PCS for advanced ovarian cancer.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA; Department of Radiology and Nuclear Medicine, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland. Electronic address: Irene.burger@usz.ch.
authors.forename: Irene A
authors.initials: IA
authors.lastname: Burger
authors.affiliation: Department of Epidemiology & Biostatistics, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Hebert Alberto
authors.initials: HA
authors.lastname: Vargas
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kattan
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Changhon
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Kou
authors.affiliation: Department of Gynecology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Vaagn
authors.initials: V
authors.lastname: Andikyan
authors.affiliation: Department of Gynecology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Dennis S
authors.initials: DS
authors.lastname: Chi
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10065, USA.
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065426:Cytoreduction Surgical Procedures; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Debulking; Ovarian carcinoma; Residual disease; Survival