title: Global distribution pattern of histological subtypes of epithelial ovarian cancer: a database analysis and systematic review.
abstract: BACKGROUND
  Epithelial ovarian cancer is basically a heterogeneous disease with different chemosensitivity and distinct molecular alternations for each histological subtype. In order to assess whether the results of clinical trials can be extrapolated to a new country, it is critical to first examine whether the relative frequencies is homogenous across countries.
  
  
  METHODS
  Cancer registry database from a single institution in Taiwan combined with systematic review of the global literature on the relative frequencies of histological subtypes between 2003 and 2012 was provided.
  
  
  RESULTS
  Of 175 titles identified, 41 studies met inclusion/exclusion criteria. Globally, for each subtype, the median value of relative frequencies for serous subtype was 45.0%, with the Philippines (16.0%), Indonesia (22.7%), and Brazil (30.1%) as the three lowest countries and South Africa (68.0%), Greece (71.5%), and India (86.7%) as the three highest countries; for mucinous subtype, 11.4%, Italy (3.0%), Australia (3.4%), and Japan (5.4%) were the three lowest countries, while Indonesia (29.1%), Singapore (30.3%), and South Korea (38.6%) were the three highest countries; for endometrioid subtype, 12.6%, India (1.6%), Greece (5.7%), and Portugal (7.6%) were the three lowest countries, while Taiwan (24.8%), Egypt (25.0%), and Austria (25.5%) were the three highest countries; and for clear cell subtype, 5.3%, Pakistan (1.0%), Iran (2.0%), and Brazil (2.1%) were the three lowest countries while Thailand (16.0%), Taiwan (16.8%), and Spain (18.8%) were the three highest countries.
  
  
  CONCLUSIONS
  Relative frequencies of subtypes were not homogenous across countries. This diversity may reflect the geographical and ethnic variations. Globally, epithelial ovarian cancer is a heterogeneous disease with a heterogeneous distribution pattern.
authors.affiliation: Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pi-Lin
authors.initials: PL
authors.lastname: Sung
authors.affiliation: Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yen-Hou
authors.initials: YH
authors.lastname: Chang
authors.affiliation: Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Kuan-Chong
authors.initials: KC
authors.lastname: Chao
authors.affiliation: Section of Gynecologic Oncology, Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Public Health, School of Medicine, National Yang-Ming University, Taiwan. Electronic address: cmjuang@gmail.com.
authors.forename: Chi-Mu
authors.initials: CM
authors.lastname: Chuang
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology* / Q000473:pathology; D018262:Adenocarcinoma, Clear Cell / Q000453:epidemiology / Q000473:pathology; D002288:Adenocarcinoma, Mucinous / Q000453:epidemiology / Q000473:pathology; D000349:Africa / Q000453:epidemiology; D001208:Asia / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D018269:Carcinoma, Endometrioid / Q000453:epidemiology / Q000473:pathology; D000077216:Carcinoma, Ovarian Epithelial; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology* / Q000473:pathology; D009656:North America / Q000453:epidemiology; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000473:pathology; D012042:Registries; D013020:South America / Q000453:epidemiology
keywords: Clinical trials; Epithelial ovarian cancer; Global; Subtype; Targeted therapy