title: Vasomotor symptoms, adoption of a low-fat dietary pattern, and risk of invasive breast cancer: a secondary analysis of the Women's Health Initiative randomized controlled dietary modification trial.
abstract: OBJECTIVE
  To assess whether the effect of a low-fat dietary pattern on breast cancer incidence varied by report of baseline vasomotor symptoms.
  
  
  METHODS
  Postmenopausal women age 50 to 79 years enrolled onto the Women's Health Initiative (WHI) Dietary Modification trial from 1993 to 1998 were randomly assigned to a low-fat dietary intervention (n = 19,541) or comparison (n = 29,294). Presence of vasomotor symptoms at baseline was ascertained from a 34-item self-report symptom inventory. Women were queried semi-annually for a new diagnosis of breast cancer. Each case report was verified by medical record and pathology report review by centrally trained WHI physician adjudicators.
  
  
  RESULTS
  Among participants who reported hot flashes (HFs) at baseline (n = 3,375), those assigned to the low-fat diet had a breast cancer rate of 0.27 compared with their counterparts in the control group who had a rate of 0.41 (hazard ratio [HR] = 0.65; 95% CI, 0.42 to 1.01). Among women reporting no HFs (n = 45,160), the breast cancer rate was 0.42 in those assigned to the low-fat diet compared with 0.46 in the control group (HR = 0.93; 95% CI, 0.84 to 1.03; P for interaction = .12 by HF status). Furthermore, the dietary benefits observed seemed to be specific to estrogen receptor (ER) -positive/progesterone receptor (PR) -positive tumors (ER positive/PR positive v other, P for risk = .03). Although women with and without HFs differed with regard to breast cancer risk factors, the effect of the diet intervention on breast cancer incidence by HF status was consistent across risk factor strata.
  
  
  CONCLUSIONS
  The results of this trial, which are hypothesis generating, suggest that HFs may identify a subgroup of postmenopausal women whose risk of invasive breast cancer might be reduced with the adoption of a low-fat eating pattern.
authors.affiliation: DrPH, Division of Research, Kaiser Permanente, 2000 Broadway, Oakland, CA 94612, USA. bette.caan@kp.org
authors.forename: Bette J
authors.initials: BJ
authors.lastname: Caan
authors.forename: Aaron
authors.initials: A
authors.lastname: Aragaki
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Thomson
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Rowan
authors.initials: R
authors.lastname: Chlebowski
authors.forename: F Allan
authors.initials: FA
authors.lastname: Hubbell
authors.forename: Lesley
authors.initials: L
authors.lastname: Tinker
authors.forename: Mara
authors.initials: M
authors.lastname: Vitolins
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Rajkovic
authors.forename: Maria
authors.initials: M
authors.lastname: Bueche
authors.forename: Judy
authors.initials: J
authors.lastname: Ockene
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology; D018752:Diet, Fat-Restricted; D005260:Female; D019584:Hot Flashes / Q000178:diet therapy*; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D017698:Postmenopause; D012307:Risk Factors
references.citation: Breast Cancer Res Treat. 1993 Sep;27(3):253-62
references.pmid: 8312583
references.citation: J Natl Cancer Inst. 2007 Mar 21;99(6):475-86
references.pmid: 17374837
references.citation: Breast Cancer Res Treat. 2008 May;109(1):123-39
references.pmid: 17578664
references.citation: J Nutr. 2006 Feb;136(2):466-72
references.pmid: 16424129
references.citation: Am J Med. 2006 Sep;119(9 Suppl 1):S52-60
references.pmid: 16949389
references.citation: J Clin Oncol. 2009 Jan 20;27(3):352-9
references.pmid: 19075284
references.citation: JAMA. 2006 Feb 8;295(6):629-42
references.pmid: 16467232
references.citation: Am J Obstet Gynecol. 2004 Dec;191(6):1979-88
references.pmid: 15592280
references.citation: Cancer Epidemiol Biomarkers Prev. 2007 Mar;16(3):439-43
references.pmid: 17372238
references.citation: J Natl Cancer Inst. 2006 Dec 20;98(24):1767-76
references.pmid: 17179478
references.citation: J Clin Oncol. 2004 Jun 15;22(12):2379-87
references.pmid: 15197199
references.citation: Menopause. 1999 Fall;6(3):209-15
references.pmid: 10486790
references.citation: JAMA. 2007 Jul 18;298(3):289-98
references.pmid: 17635889
references.citation: J Natl Cancer Inst. 1990 Jan 17;82(2):129-34
references.pmid: 2294222
references.citation: J Clin Oncol. 2005 Dec 20;23(36):9295-303
references.pmid: 16361628
references.citation: Yao Xue Xue Bao. 2007 Jan;42(1):8-12
references.pmid: 17520800
references.citation: Arch Intern Med. 2006 Nov 13;166(20):2253-9
references.pmid: 17101944
references.citation: Breast Cancer Res Treat. 2008 Apr;108(3):421-6
references.pmid: 17541741
references.citation: Res Nurs Health. 1985 Sep;8(3):261-8
references.pmid: 3852361
references.citation: Menopause. 2006 Nov-Dec;13(6):902-10
references.pmid: 16977255
references.citation: J Clin Oncol. 2005 Dec 20;23(36):9312-8
references.pmid: 16361630
references.citation: Am J Public Health. 2006 Jul;96(7):1226-35
references.pmid: 16735636