title: Comparison of survival outcomes between patients with malignant mixed mullerian tumors and high-grade endometrioid, clear cell, and papillary serous endometrial cancers.
abstract: BACKGROUND
  Malignant mixed mullerian tumors (MMMTs) are an aggressive subtype of endometrial cancer (EC). Previous studies compare survival between high-grade endometrioid (EM), clear cell (CC), and papillary serous (PS) ECs; yet few studies compare MMMTs to these aggressive subtypes. The goal of this study was to compare recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) among EC subtypes.
  
  
  METHODS
  We conducted a retrospective cohort study of EC cases treated at Magee-Women's Hospital between 1996 and 2008. Kaplan-Meier estimates of RFS, DSS, and OS as well as and log-rank tests were used to compare survival distributions between histologic subtypes. Cox regression was used to estimate hazard ratios for histologic subtypes, adjusted for other significant prognostic factors. Interactions between histologic subtype and prognostic factors were examined to assess effect modification.
  
  
  RESULTS
  This cohort included 81 MMMT (15%), 254 high-grade EM (46%), 73 CC (13%), and 147 PS (26%) cases. Compared to high-grade EM (6%) and CC (7%) cases, relatively more MMMT (12%) and PS (12%) cases were nonwhite. Stage differed significantly among the subtypes, with 36%, 34%, 37%, and 51% of MMMT, high-grade EM, CC, and PS cases, respectively, diagnosed at advanced late stage (P<0.001). Kaplan-Meier curves and log-rank tests showed similar RFS, DSS, and OS between MMMT, high-grade EM, CC, and PS cases stratified by stage. In adjusted Cox regression models, RFS and DSS were not significantly different between MMMT and other subtypes. High-grade EM cases had a significantly better OS compared to MMMT cases (HR, 0.63; 95% confidence interval [CI], 0.41-0.98).
  
  
  CONCLUSIONS
  This is the first retrospective study to suggest that certain survival outcomes are similar among MMMT, high-grade EM, CC, and PS subtypes. Other large-scale studies are needed to confirm these findings.
authors.affiliation: Division of Cancer Prevention and Population Science, University of Pittsburgh Cancer Institute, Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, and Department of Obstetrics and Gynecologic Oncology, Magee-Women's Hospital of UPMC Health System, Pittsburgh, PA 15232, USA. asf23@pitt.edu
authors.forename: Ashley Sinclair
authors.initials: AS
authors.lastname: Felix
authors.forename: Roslyn A
authors.initials: RA
authors.lastname: Stone
authors.forename: Robert
authors.initials: R
authors.lastname: Bowser
authors.forename: Mamatha
authors.initials: M
authors.lastname: Chivukula
authors.forename: Robert P
authors.initials: RP
authors.lastname: Edwards
authors.forename: Joel L
authors.initials: JL
authors.lastname: Weissfeld
authors.forename: Faina
authors.initials: F
authors.lastname: Linkov
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D000368:Aged; D018269:Carcinoma, Endometrioid / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D002291:Carcinoma, Papillary / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D015331:Cohort Studies; D018284:Cystadenocarcinoma, Serous / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D016889:Endometrial Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D018200:Mixed Tumor, Mullerian / Q000175:diagnosis / Q000401:mortality* / Q000473:pathology; D060787:Neoplasm Grading; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis