title: Importance of hereditary and selected environmental risk factors in the etiology of inflammatory breast cancer: a case-comparison study.
abstract: To assess the importance of heredity in the etiology of inflammatory breast cancer (IBC), we compared IBC patients to several carefully chosen comparison groups with respect to the prevalence of first-degree family history of breast cancer.
  
  
  
  IBC cases (n = 141) were compared to non-inflammatory breast cancer cases (n = 178) ascertained through George Washington University (GWU) with respect to the prevalence of first-degree family history of breast cancer and selected environmental/lifestyle risk factors for breast cancer. Similar comparisons were conducted with subjects from three case-control studies: breast cancer cases (n = 1145) and unaffected controls (n = 1142) from the Cancer Genetic Markers of Susceptibility (CGEMS) study, breast cancer cases (n = 465) and controls (n = 9317) from the Women's Health Initiative (WHI) study, and ovarian cancer cases (n = 260) and controls (n = 331) from a study by University of Toronto (UT).
  
  
  
  The frequency of first-degree breast cancer family history among IBC cases was 17.0 % compared to 24.4 % for GWU breast cancer cases, 23.9 % and 17.9 % for CGEMS breast cancer cases and controls, respectively, 16.9 % and 12.6 % for WHI breast cancer cases and controls, respectively, and 24.2 % and 11.2 % for UT ovarian cancer cases and controls, respectively. IBC cases had a significantly lower prevalence of parous women than WHI breast cancer cases (OR = 0.46, 95 % CI:0.27-0.81) and controls (OR = 0.31, 95 % CI:0.20-0.49). Oral contraceptive use was significantly higher among IBC cases compared to WHI breast cancer cases (OR = 7.77, 95 % CI:4.82-12.59) and controls (OR = 8.14, 95 % CI:5.28-12.61). IBC cases had a significantly higher frequency of regular alcohol consumption (≥1 drink per day) compared to WHI controls (OR = 1.84, 95 % CI:1.20-2.82) and UT controls (OR = 1.86, 95 % CI:1.07-3.22) and higher (statistically non-significant) prevalence (21.3 %) compared to breast cancer cases from GWU (18.2 %) and WHI (15.2 %).
  
  
  
  The prevalence of first-degree breast cancer family history among IBC cases was lower compared to breast and ovarian cancer cases but higher than unaffected individuals. Our multiple-case inflammatory and non-inflammatory breast cancer families may reflect aggregation of common genetic and/or environmental factors predisposing to both types of breast cancer. Our findings that oral contraceptive use and regular alcohol consumption may be associated with IBC warrant further investigations.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, Albany, NY, 12144, USA. rmoslehi@albany.edu.|Cancer Research Center, University at Albany, Room 208, 1 Discovery Drive, Albany, NY, 12144, USA. rmoslehi@albany.edu.
authors.forename: Roxana
authors.initials: R
authors.lastname: Moslehi
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health and Health Services, The George Washington University, Washington, DC, 20037, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Freedman
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, University at Albany, Albany, NY, 12144, USA.
authors.forename: Nur
authors.initials: N
authors.lastname: Zeinomar
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health and Health Services, The George Washington University, Washington, DC, 20037, USA.
authors.forename: Carmela
authors.initials: C
authors.lastname: Veneroso
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health and Health Services, The George Washington University, Washington, DC, 20037, USA. paulhlevine@earthlink.net.|Department of Epidemiology, College of Public Health, University of Nebraska, Omaha, NE, 68198, USA. paulhlevine@earthlink.net.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Levine
mesh_terms: D016022:Case-Control Studies; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors
keywords: Breast cancer risk factors; Case-comparison study; Family history of breast cancer; Heredity; IBC; Inflammatory breast cancer; Multiplex IBC families