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@ARTICLE{LeCornet:302816,
      author       = {C. Le Cornet$^*$ and A. Y. Jung$^*$ and S. Behrens$^*$ and
                      P. Middha$^*$ and T. Truong and H. Jernström and M. K.
                      Bolla and Q. Wang and M. C. Southey and L. E. Beane Freeman
                      and S. Koutros and J. Stone and G. Rennert and K. Shulman
                      and K. J. Aronson and R. A. Murphy and P. Guénel and A. V.
                      Patel and C. Bodelon and L. R. Teras and S. Shahi and J. V.
                      Lacey and L. Dossus and R. Kaaks$^*$ and B. Holleczek and H.
                      Brenner$^*$ and H. Brauch$^*$ and R. Hoppe and K. Czene and
                      P. F. L. Hall and A. Mannermaa and A. H. Wu and N. Obi and
                      K. Michailidou and M. I. Panayiotidis and C. McLean and C.
                      A. Haiman and A. Augustinsson and W. Zheng and X.-O. Shu and
                      C. M. Perou and M. A. Troester and S. Van Alsten and A. H.
                      Eliassen and M. Abubakar and P. Kraft and T. U. Ahearn and
                      D. G. Evans and A. Wolk and R. L. Milne and D. F. Easton and
                      P. D. P. Pharoah and M. K. Schmidt and M. García-Closas and
                      C. M. Vachon and R. Turzanski-Fortner$^*$ and J.
                      Chang-Claude$^*$},
      title        = {{E}xogenous {H}ormones, {T}umor {I}ntrinsic {S}ubtypes, and
                      {B}reast {C}ancer.},
      journal      = {JAMA network open},
      volume       = {8},
      number       = {7},
      issn         = {2574-3805},
      address      = {Chicago, Ill.},
      publisher    = {American Medical Association},
      reportid     = {DKFZ-2025-01356},
      pages        = {e2519236},
      year         = {2025},
      note         = {#EA:C020#LA:C020#},
      abstract     = {Etiologic heterogeneity in breast carcinogenesis needs to
                      be well characterized for targeted prevention. Associations
                      between menopausal hormonal therapy (MHT) and oral
                      contraceptive (OC) use and breast cancer intrinsic-like
                      subtypes are not well understood.To examine whether
                      exogenous hormone use is differentially associated with
                      breast cancer subtypes and to evaluate heterogeneity by
                      intrinsic-like subtypes.This study pooled data from 31
                      nested and population-based case-control studies involved in
                      the Breast Cancer Association Consortium. The study
                      population included individuals with breast cancer and
                      control participants from 13 case-control studies nested in
                      prospective cohorts (recruited between 1982 and 2011) and 18
                      population-based case-control studies (recruited between
                      1990 and 2013). Data analysis was performed in June 2024.MHT
                      use (estrogen-progestin therapy [EPT] or estrogen-only
                      therapy [ET]) in postmenopausal women and OC use in
                      premenopausal women (never, past use, or current use).Breast
                      cancer intrinsic-like subtypes (luminal A-like, luminal
                      B-like, luminal B-ERBB2 [formerly HER2 or HER2/neu]-like,
                      ERBB2 enriched-like, or triple-negative) were determined by
                      immunohistochemistry of tumor sections. Polytomous logistic
                      regression was performed to estimate the association between
                      exogenous hormones and risk of breast cancer by
                      intrinsic-like subtypes. Analyses by subtypes were
                      stratified by body mass index (BMI [calculated as weight in
                      kilograms divided by height in meters squared]; healthy
                      weight, 18.5-<25; overweight, 25-<30; or obesity,
                      ≥30).This study included 42 269 individuals with breast
                      cancer (11 901 $[28.2\%]$ premenopausal and 30 368
                      $[71.8\%]$ postmenopausal; 23 353 $[55.2\%]$ had a known
                      intrinsic-like subtype) and 71 072 control participants. The
                      mean (SD) age of all participants was 57.9 (10.9) years. In
                      postmenopausal women, associations between current MHT use
                      (EPT or ET) and breast cancer differed by subtype. Current
                      EPT users with healthy weight were more likely to be
                      diagnosed with luminal A-like (odds ratio [OR], 2.51 $[95\%$
                      CI, 2.26-2.80]) or luminal B-ERBB2-like (OR, 1.95 $[95\%$
                      CI, 1.61-2.37]) subtypes. These associations were attenuated
                      but remained for individuals with overweight (OR, 1.40
                      $[95\%$ CI, 1.02-1.92]) or obesity (OR, 1.68 $[95\%$ CI,
                      1.01-2.78]). EPT use increased the odds of being diagnosed
                      with luminal B-like tumors solely in women with healthy
                      weight (OR, 1.47 $[95\%$ CI, 1.17-1.86]). Current ET use was
                      positively associated with luminal A-like disease in women
                      with healthy weight only (OR, 1.16 $[95\%$ CI, 1.01-1.32]),
                      showing inverse associations with higher BMI (obesity: OR,
                      0.65 $[95\%$ CI, 0.50-0.85]). In premenopausal women, recent
                      OC use was associated with luminal B-ERBB2-like (OR, 1.50
                      $[95\%$ CI, 1.09-2.08]), ERBB2 enriched-like (OR, 2.33
                      $[95\%$ CI, 1.55-3.51]), and triple-negative (OR, 1.75
                      $[95\%$ CI, 1.33-2.29]; P < .04 for heterogeneity) tumors.In
                      this study, clear differences were observed in associations
                      between current EPT use and luminal-like breast cancer
                      subtypes and other subtypes. EPT users with healthy weight
                      were more likely to be diagnosed with luminal-like breast
                      cancer compared with nonusers. Subtype heterogeneity was
                      less apparent in associations of OC and ET use. Future
                      studies on contemporary formulations, patterns of use, and
                      routes of administration of exogenous hormone usage are
                      warranted.},
      keywords     = {Humans / Female / Breast Neoplasms: epidemiology / Breast
                      Neoplasms: classification / Breast Neoplasms: chemically
                      induced / Breast Neoplasms: pathology / Middle Aged /
                      Case-Control Studies / Postmenopause / Adult / Prospective
                      Studies / Aged / Contraceptives, Oral: adverse effects /
                      Premenopause / Estrogen Replacement Therapy: adverse effects
                      / Estrogen Replacement Therapy: statistics $\&$ numerical
                      data / Contraceptives, Oral (NLM Chemicals)},
      cin          = {C020 / C070 / HD01 / TU01},
      ddc          = {610},
      cid          = {I:(DE-He78)C020-20160331 / I:(DE-He78)C070-20160331 /
                      I:(DE-He78)HD01-20160331 / I:(DE-He78)TU01-20160331},
      pnm          = {313 - Krebsrisikofaktoren und Prävention (POF4-313)},
      pid          = {G:(DE-HGF)POF4-313},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:40622713},
      pmc          = {pmc:PMC12235495},
      doi          = {10.1001/jamanetworkopen.2025.19236},
      url          = {https://inrepo02.dkfz.de/record/302816},
}