Blood levels of cadmium and lead in relation to breast cancer risk in three prospective cohorts

Research output: Contribution to journalArticle

Abstract

Cadmium and lead have been classified as carcinogens by the International Agency for Research on Cancer. However, their associations with breast cancer risk are unknown despite their persistence in the environment and ubiquitous human exposure. We examined associations of circulating levels of cadmium and lead with breast cancer risk in three case–control studies nested within the Cancer Prevention Study-II (CPS-II) LifeLink Cohort, European Prospective Investigation into Cancer and Nutrition – Italy (EPIC-Italy) and the Northern Sweden Health and Disease Study (NSHDS) cohorts. Metal levels were measured in stored erythrocytes from 1,435 cases and 1,433 controls using inductively coupled plasma-mass spectrometry. Summary relative risks (RR) and 95% confidence intervals (CI) were calculated using random-effects models with each study result weighted by the within- and between-study variances. I2 values were calculated to estimate proportion of between study variation. Using common cut-points, cadmium levels were not associated with breast cancer risk in the CPS-II cohort (continuous RR = 1.01, 95% CI 0.76–1.34), but were inversely associated with risk in the EPIC- Italy (continuous RR = 0.80, 95% CI 0.61–1.03) and NSHDS cohorts (continuous RR = 0.73, 95% CI 0.54–0.97). The inverse association was also evident in the meta-analysis (continuous RR = 0.84, 95% CI 0.69–1.01) with low between-study heterogeneity. Large differences in lead level distributions precluded a meta-analysis of their association with breast cancer risk; no associations were found in the three studies. Adult cadmium and lead levels were not associated with higher risk of breast cancer in our large meta-analysis.

Details

Authors
  • Mia M. Gaudet
  • Emily L. Deubler
  • Rachel S. Kelly
  • W. Ryan Diver
  • Lauren R. Teras
  • James M. Hodge
  • Keith E. Levine
  • Laura G. Haines
  • Thomas Lundh
  • Per Lenner
  • Domenico Palli
  • Paolo Vineis
  • Ingvar A. Bergdahl
  • Susan M. Gapstur
  • Soterios A. Kyrtopoulos
Organisations
External organisations
  • American Cancer Society
  • Brigham and Women's Hospital / Harvard Medical School
  • RTI International
  • Umeå University
  • Imperial College London
  • Cancer Research and Prevention Institute (ISPO)
  • National Hellenic Research Foundation
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology
  • Environmental Health and Occupational Health

Keywords

  • breast cancer, cadmium, lead
Original languageEnglish
Pages (from-to)1010-1016
JournalInternational Journal of Cancer
Volume144
Issue number5
Early online date2018 Aug 17
Publication statusPublished - 2019 Mar 1
Publication categoryResearch
Peer-reviewedYes