title: Postmenopausal hormone therapy and non-Hodgkin lymphoma: a pooled analysis of InterLymph case-control studies.
abstract: BACKGROUND
  Non-Hodgkin lymphoma (NHL) subtypes, diffuse large B-cell (DLBCL) and follicular lymphoma (FL) have different sex ratios and are diagnosed at ages over 60 years; DLBCL is more common in men and diagnosed at older ages than FL, which occurs more among women. This analysis of postmenopausal women examines the relationship between postmenopausal hormone therapy and NHL.
  
  
  METHODS
  Self-reported use of postmenopausal hormone therapy from 2094 postmenopausal women with NHL and 2731 without were pooled across nine case-control studies (1983-2005) from North America, Europe and Japan. Study-specific odds ratios (OR) and 95% confidence intervals (CI) estimated using logistic regression were pooled using random-effects meta-analyses.
  
  
  RESULTS
  Postmenopausal women who used hormone therapy were at decreased risk of NHL (pooled OR = 0.79, 95% CI 0.69-0.90). Risks were reduced when the age of starting was 50 years or older. There was no clear trend with number of years of use. Current users were at decreased risk while those stopping over 2 years before diagnosis were not. Having a hysterectomy or not did not affect the risk. Favourable effects were present for DLBCL (pooled OR = 0.66, 95% CI 0.54-0.80) and FL (pooled OR = 0.82, 95% CI 0.66-1.01).
  
  
  CONCLUSIONS
  Postmenopausal hormone therapy, particularly used close to menopause, is associated with a decreased risk of NHL.
authors.affiliation: Epidemiology and Genetics Unit, Department of Health Sciences, University of York, York, UK. Electronic address: eleanor.kane@egu.york.ac.uk.
authors.forename: E V
authors.initials: EV
authors.lastname: Kane
authors.affiliation: Department of Population Sciences, Division of Cancer Etiology, City of Hope National Medical Center, Duarte.
authors.forename: L
authors.initials: L
authors.lastname: Bernstein
authors.affiliation: Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco.
authors.forename: P M
authors.initials: PM
authors.lastname: Bracci
authors.affiliation: Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Cerhan
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, CIBERESP, Catalan Institute of Oncology, Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Costas
authors.affiliation: Epidemiology and Biostatistics Unit, Aviano Cancer Centre, Aviano.
authors.forename: L
authors.initials: L
authors.lastname: Dal Maso
authors.affiliation: Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco.
authors.forename: E A
authors.initials: EA
authors.lastname: Holly
authors.affiliation: Department of Occupational Medicine, Istituto di Ricerche Farmacologiche 'Mario Negri', Universitá degli Studi di Milano, Milan, Italy.
authors.forename: C
authors.initials: C
authors.lastname: La Vecchia
authors.affiliation: Division of Epidemiology and Prevention, Aichi Cancer Center, Nagoya, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsuo
authors.affiliation: Unit of Infections and Cancer, Cancer Epidemiology Research Programme, IDIBELL, CIBERESP, Catalan Institute of Oncology, Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Sanjose
authors.affiliation: Cancer Control Research, BC Cancer Agency Research Center, Vancouver, British Columbia, Canada.
authors.forename: J J
authors.initials: JJ
authors.lastname: Spinelli
authors.affiliation: Department of Population Sciences, Division of Cancer Etiology, City of Hope National Medical Center, Duarte.
authors.forename: S S
authors.initials: SS
authors.lastname: Wang
authors.affiliation: School of Public Health, Yale University, New Haven, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Public Health, Yale University, New Haven, USA.
authors.forename: T
authors.initials: T
authors.lastname: Zheng
authors.affiliation: Epidemiology and Genetics Unit, Department of Health Sciences, University of York, York, UK.
authors.forename: E
authors.initials: E
authors.lastname: Roman
authors.affiliation: Sydney School of Public Health, The University of Sydney, Sydney, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Kricker
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008224:Lymphoma, Follicular / Q000453:epidemiology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D017698:Postmenopause; D012306:Risk