title: Brachytherapy Is Associated With Improved Survival in Inoperable Stage I Endometrial Adenocarcinoma: A Population-Based Analysis.
abstract: OBJECTIVE
  To assess the use of brachytherapy (BT) with or without external beam radiation (EBRT) in inoperable stage I endometrial adenocarcinoma in the United States and to determine the effect of BT on overall survival (OS) and cause-specific survival (CSS).
  
  
  METHODS
  Data between 1998 and 2011 from the National Cancer Institute's Surveillance, Epidemiology and End Results database were analyzed. Coarsened exact matching was used to adjust for differences in age and grade between patients who received BT and those who did not. Prognostic factors affecting OS and CSS were evaluated using the Kaplan-Meier product-limit method and a Cox proportional hazards regression model.
  
  
  RESULTS
  A total of 460 patients with inoperable stage I endometrial adenocarcinoma treated with radiation therapy were identified. Radiation consisted of either EBRT (n=260) or BT with or without EBRT (n=200). The only factor associated with BT use was younger patient age (median age, 72 vs 76 years, P=.001). Patients who received BT had a higher 3-year OS (60% vs 47%, P<.001) and CSS (82% vs 74%, P=.032) compared with those who did not. On multivariate analysis, BT use was independently associated with an improved OS (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.52-0.87) and CSS (HR 0.61, 95% CI 0.39-0.93). When patients were matched on age, BT use remained significant on multivariate analysis for OS (HR 0.65, 95% CI 0.48-0.87) and CSS (HR 0.52, 95% CI 0.31-0.84). When matched on age and grade, BT remained independently associated with improved OS and CSS (OS HR 0.62, 95% CI 0.46-0.83; CSS HR 0.57, 95% CI 0.34-0.92).
  
  
  CONCLUSIONS
  Brachytherapy is independently associated with improved OS and CSS. It should be considered as part of the treatment regimen for stage I inoperable endometrial cancer patients undergoing radiation.
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Sahaja
authors.initials: S
authors.lastname: Acharya
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Perkins
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Todd
authors.initials: T
authors.lastname: DeWees
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Fischer-Valuck
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: David G
authors.initials: DG
authors.lastname: Mutch
authors.affiliation: Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Powell
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Julie K
authors.initials: JK
authors.lastname: Schwarz
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri. Electronic address: pgrigsby@radonc.wustl.edu.
authors.forename: Perry W
authors.initials: PW
authors.lastname: Grigsby
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001918:Brachytherapy / Q000379:methods / Q000401:mortality* / Q000706:statistics & numerical data; D002423:Cause of Death; D016889:Endometrial Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D018426:SEER Program; D016019:Survival Analysis