RE: Night Shift Work and Breast Cancer Incidence: Three Prospective Studies and Meta-Analysis of Published Studies

Details

• Personal Author:
  Schernhammer ES
• Description:
  I read with interest the findings of a recent mega-study and meta-analysis on night shift work and breast cancer risk published in the Journal (J Natl Cancer Inst. 2016;108(12):djw169). Travis et al. write that - with reference to a 2007 International Agency for Research on Cancer (IARC) classification of night shift work as a probable carcinogen - although further follow-up is desirable, "The prospective evidence now available shows that classification of night shift work as a probable (human) carcinogen is no longer justified." I disagree with the authors' assessment. Travis et al. report that among their 795,850 mostly retired elderly women, whom they followed for incident breast cancer for two to three years in late life, there was no increase in breast cancer risk after night work. They classify these women as night workers with as little as a single night shift at some time in their entire life. ... Travis' null findings do not amount at all to a wholesale rejection of the "melatonin hypothesis" as the authors seem to suggest. In other words, rejecting the possibility of night shift work as a potential carcinogen on the basis of a reported null finding between minimal exposure to night shift work and breast cancer risk in a very narrow time window during older age in one publication seems like bad science, and tantamount to "throwing the baby out with the bath water." Instead, the research community and night workers at large will be served much better if we follow up on first steps toward precision prevention and delineating periods and phenotypes of, or at, increased risk. [Description provided by NIOSH]
• Subjects:
  Age Factors Aging Carcinogens Circadian Rhythm Epidemiology Health Personnel Neoplasms Occupational Health Risk Assessment Risk Factors Safety Shift Work Schedule Women

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• Keywords:
  Age Factors Age Groups Biological Rhythms Breast Cancer Cancer Circadian Rhythms Exposure Assessment Health Care Personnel Health Care Workers Humans Malignant Neoplasms Nurses Nursing Risk Factors Shift Work Shift Workers

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• ISSN:
  0027-8874
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; OSHA Region 1
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  109
• Issue:
  4
• NIOSHTIC Number:
  nn:20051931
• Citation:
  J Natl Cancer Inst 2017 Apr; 109(4):djx002
• Contact Point Address:
  Eva Schernhammer, MD, DrPH, 181 Longwood Avenue, Boston, MA 02155
• Email:
  eva.schernhammer@channing.harvard.edu
• Federal Fiscal Year:
  2017
• Performing Organization:
  Brigham and Women's Hospital, Inc., Boston, Massachusetts
• Peer Reviewed:
  False
• Start Date:
  20100801
• Source Full Name:
  Journal of the National Cancer Institute
• End Date:
  20190831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f188ec7d2b06bb967793fc62a5e0e408cf67217a26c4a3ba5300baa1d050aa5de893149e94d4357b3b43153f40d8f2e8759fe1d86e8ac37e3739792cad2fedae
• Download URL:
  https://stacks.cdc.gov/view/cdc/211595/cdc_211595_DS1.pdf
• File Type:
  [PDF - 567.58 KB ]