Recent trends in hormone therapy utilization and breast cancer incidence rates in the high incidence population of Marin County, California

Details

• Alternative Title:
  BMC Public Health
• Personal Author:
  Ereman, Rochelle R ; Prebil, Lee Ann ; Mockus, Mary ; Koblick, Kathy ; Orenstein, Fern ; Benz, Christopher ; Clarke, Christina A
• Description:
  Background
  
  Recent declines in invasive breast cancer have been reported in the US, with many studies linking these declines to reductions in the use of combination estrogen/progestin hormone therapy (EPHT). We evaluated the changing use of postmenopausal hormone therapy, mammography screening rates, and the decline in breast cancer incidence specifically for Marin County, California, a population with historically elevated breast cancer incidence rates.
  
  Methods
  
  The Marin Women's Study (MWS) is a community-based, prospective cohort study launched in 2006 to monitor changes in breast cancer, breast density, and personal and biologic risk factors among women living in Marin County. The MWS enrolled 1,833 women following routine screening mammography between October 2006 and July 2007. Participants completed a self-administered questionnaire that included items regarding historical hormone therapy regimen (estrogen only, progesterone only, EPHT), age of first and last use, total years of use, and reason(s) for stopping, as well as information regarding complementary hormone use. Questionnaire items were analyzed for 1,083 non-Hispanic white participants ages 50 and over. Breast cancer incidence rates were assessed overall and by tumor histology and estrogen receptor (ER) status for the years 1990-2007 using data from the Northern California Surveillance, Epidemiology and End Results (SEER) cancer registry.
  
  Results
  
  Prevalence of EPHT use among non-Hispanic white women ages 50 and over declined sharply from 21.2% in 1998 to 6.7% by 2006-07. Estrogen only use declined from 26.9% in 1998 to 22.4% by 2006-07. Invasive breast cancer incidence rates declined 33.4% between 2001 and 2004, with drops most pronounced for ER+ cancers. These rate reductions corresponded to declines of about 50 cases per year, consistent with population attributable fraction estimates for EPHT-related breast cancer. Self-reported screening mammography rates did not change during this period. Use of alternative or complementary agents did not differ significantly between ever and never hormone users. Of women who reported stopping EPHT in the past 5 years, 60% cited "health risks" or "news reports" as their primary reasons for quitting.
  
  Conclusion
  
  A dramatic reduction in EPHT use was followed temporally by a significant reduction in invasive and ER+ breast cancer rates among women living in Marin County, California.
  
  
• Subjects:
  Attitude To Health Breast Neoplasms Estrogen Replacement Therapy Female Humans Incidence Mammography Mass Screening Middle Aged Prospective Studies Questionnaires Research Article Risk Factors

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• Source:
  BMC Public Health. 2010; 10:228.
• Pubmed ID:
  20433756
• Pubmed Central ID:
  PMC2876106
• Document Type:
  Journal Article
• Funding:
  N01-PC-35136/PC/NCI NIH HHS/United States ; N01-PC-35139/PC/NCI NIH HHS/United States ; N02-PC-15105/PC/NCI NIH HHS/United States ; R01 DP000217/DP/NCCDPHP CDC HHS/United States ; U55/CCR921930-02/PHS HHS/United States
• Place as Subject:
  California
• Volume:
  10
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:dabd715bccde1d83dd33dd4a84cdb80a38f25e44fc1c6918b9388c7d11328f2e
• Download URL:
  https://stacks.cdc.gov/view/cdc/22908/cdc_22908_DS1.pdf
• File Type:
  [PDF - 839.09 KB ]