title: Risk of subsequent endometrial carcinoma associated with endometrial intraepithelial neoplasia classification of endometrial biopsies.
abstract: BACKGROUND
  Histopathologic diagnosis of endometrial biopsies is used to estimate the risk of progression to carcinoma and guide clinical management. Problems with the widely used World Health Organization (WHO) system for classifying endometrial hyperplasia (EH) have prompted the development of an alternative system based on endometrial intraepithelial neoplasia (EIN). The authors estimated progression risk associated with EIN among endometrial biopsies in a nested case-control study of EH progression.
  
  
  METHODS
  Index biopsies with original community pathology diagnoses of disordered proliferative endometrium (DPEM) or EH that were independently confirmed by a panel of pathologists were independently reviewed and assigned EIN classifications (inadequate, benign, EIN, or cancer) by a second panel of pathologists. Cases (N = 138) progressed to carcinoma at least 1 year (median, 6 years) after their index biopsy. Controls (N = 241) also had EH, did not progress to carcinoma, and were individually matched to cases based on age at EH, date of EH, and length of follow-up. By using conditional logistic regression, the authors estimated relative risks (RRs) with 95% confidence intervals (95% CIs) for progression to carcinoma for EIN versus benign.
  
  
  RESULTS
  In the EIN system, 71 (52.6%) cases and 159 (66.8%) controls were classified as benign and 42 (31.1%) cases and 65 (27.3%) controls were classified as EIN. The RR for EIN versus benign was 7.76 (95% CI, 3.36-17.91). In the WHO system, the RR for atypical hyperplasia (AH) versus DPEM, simple hyperplasia, or complex hyperplasia was 9.19 (95% CI, 3.87-21.83).
  
  
  CONCLUSIONS
  Among women observed for at least 1 year after receiving a biopsy-based EH diagnosis, EIN and AH were both found to have similarly increased risks of progression to carcinoma.
authors: Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, Maryland 20852-7234, USA. jimlacey@nih.gov
authors: James V
authors: JV
authors: Lacey
authors: George L
authors: GL
authors: Mutter
authors: Marisa R
authors: MR
authors: Nucci
authors: Brigitte M
authors: BM
authors: Ronnett
authors: Olga B
authors: OB
authors: Ioffe
authors: Brenda B
authors: BB
authors: Rush
authors: Andrew G
authors: AG
authors: Glass
authors: Douglas A
authors: DA
authors: Richesson
authors: Nilanjan
authors: N
authors: Chatterjee
authors: Bryan
authors: B
authors: Langholz
authors: Mark E
authors: ME
authors: Sherman
mesh_terms: D000328:Adult; D001706:Biopsy; D018450:Disease Progression; D004714:Endometrial Hyperplasia / Q000145:classification* / Q000473:pathology; D016889:Endometrial Neoplasms / Q000145:classification* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D011230:Precancerous Conditions / Q000145:classification / Q000473:pathology; D012306:Risk; D002583:Uterine Cervical Neoplasms / Q000145:classification* / Q000473:pathology; D002578:Uterine Cervical Dysplasia / Q000145:classification* / Q000473:pathology