title: Tumor Characteristics and Survival Outcome of Endometrial Cancer Arising in Adenomyosis: An Exploratory Analysis.
abstract: BACKGROUND
  Endometrial cancer arising in adenomyosis (EC-AIA) is a rare entity of endometrial cancer, and its clinical significance has not been well studied. This study aimed to examine the tumor characteristics and survival outcomes of EC-AIA.
  
  
  METHODS
  An exploratory analysis was performed to compare EC-AIA and historical control cases. For this study, EC-AIA cases were identified via a systematic literature search using PubMed/MEDLINE with entry keywords "endometrial cancer OR uterine cancer" AND "adenomyosis" (n = 46). The control group comprised consecutive non-EC-AIA cases from four institutions that had hysterectomy-based surgical staging (n = 1294). Patient demographics, pathology results, and survival outcomes were evaluated between the two groups.
  
  
  RESULTS
  The EC-AIA group was significantly older than the control group (58.9 vs. 55.3 years; P = 0.032). In terms of tumor characteristics, 56.5% of the EC-AIA cases showed tumor within the myometrium without endometrial extension, and the EC-AIA group was significantly more likely to have tumors with more than 50% myometrial invasion (51.6 vs. 26.6%; P = 0.002) and serous/clear cell histology (22.2 vs. 8.2%, P = 0.002) while less likely to express estrogen receptor (14.3 vs. 84.6%; P < 0.001). Grade and stage distributions were similar (P > 0.05). In the univariate analysis, the EC-AIA group had a significantly poorer disease-free survival than the control group (5-year rate: 71.4 vs. 80.6%; P = 0.014). In the multivariate analysis, with control for age, ethnicity, histology, grade, and stage, EA-CIC remained an independent prognostic factor for decreased disease-free survival (adjusted hazard ratio, 3.07; 95% confidence interval 1.55-6.08; P = 0.001).
  
  
  CONCLUSIONS
  The study suggested that endometrial cancer arising in adenomyosis may be an aggressive variant of endometrial cancer.
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA. koji.matsuo@med.usc.edu.|Norris Comprehensive Cancer Center, Los Angeles, CA, USA. koji.matsuo@med.usc.edu.
authors.forename: Koji
authors.initials: K
authors.lastname: Matsuo
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA.
authors.forename: Aida
authors.initials: A
authors.lastname: Moeini
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Machida
authors.affiliation: Keck School of Medicine, Los Angeles, CA, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Scannell
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Casabar
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kakuda
authors.affiliation: Department of Obstetrics and Gynecology, Niigata University Graduate School of Medicine, Niigata, Japan.
authors.forename: Sosuke
authors.initials: S
authors.lastname: Adachi
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA.
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Garcia-Sayre
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ueda
authors.affiliation: Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA.|Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: Lynda D
authors.initials: LD
authors.lastname: Roman
mesh_terms: D062788:Adenomyosis / Q000150:complications / Q000401:mortality* / Q000473:pathology*; D016022:Case-Control Studies; D016889:Endometrial Neoplasms / Q000209:etiology / Q000401:mortality* / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate