title: Is hormone replacement therapy in post-menopausal women associated with a reduced risk of oesophageal cancer?
abstract: OBJECTIVE
  The rise in oesophageal adenocarcinoma incidence in women with age is delayed compared with men until the post-menopausal period. A matched cohort study was therefore undertaken of post-menopausal women on hormone replacement therapy (HRT) to examine the association between HRT, oesophageal cancer and the potentially associated conditions, reflux oesophagitis and Barrett's oesophagus.
  
  
  METHODS
  Women aged over 50 years within the UK General Practice Research Database with a history of HRT exposure were matched by age and general practice with controls without HRT exposure (1:1). Matched Cox-regression analysis was performed to estimate adjusted hazard ratios.
  
  
  RESULTS
  51,851 HRT users and controls were studied. Prolonged HRT use for 5-10 years (hazard ratio 0.25 (95% CI 0.07-0.95)) and time-dependent covariates for increasing duration of HRT use (0.06 (0.01-0.43)) were associated with a reduced oesophageal cancer risk. HRT use was associated with reflux oesophagitis (1.27 (1.12-1.43)), but when analysis was confined to women with codes for both reflux oesophagitis and endoscopy there was no association (1.1 (0.81-1.44)), suggesting increased reporting of reflux symptoms among HRT users rather than an association with endoscopic reflux oesophagitis.
  
  
  CONCLUSIONS
  Long-term post-menopausal HRT may be associated with a reduced risk of oesophageal cancer.
authors.affiliation: Royal Wolverhampton NHS Trust, Wolverhampton, UK.
authors.forename: Shyam
authors.initials: S
authors.lastname: Menon
authors.affiliation: Wolfson Computer Laboratories, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Nightingale
authors.affiliation: Sandwell General Hospital, West Bromwich, UK.
authors.forename: Nigel
authors.initials: N
authors.lastname: Trudgill
keywords: Barrett’s oesophagus; Hormone replacement therapy; oesophageal adenocarcinoma; oesophageal cancer; oesophageal squamous cell carcinoma; reflux oesophagitis