Environment International (May 2022)

Dietary intakes of dioxins and polychlorobiphenyls (PCBs) and breast cancer risk in 9 European countries

  • Thibault Fiolet,
  • Corinne Casagrande,
  • Geneviève Nicolas,
  • Zsuzsanna Horvath,
  • Pauline Frenoy,
  • Elisabete Weiderpass,
  • Verena Katzke,
  • Rudolf Kaaks,
  • Miguel Rodriguez-Barranco,
  • Salvatore Panico,
  • Carlotta Sacerdote,
  • Jonas Manjer,
  • Emily Sonestedt,
  • Sara Grioni,
  • Antonio Agudo,
  • Charlotta Rylander,
  • Therese Haugdahl Nøst,
  • Guri Skeie,
  • Anne Tjønneland,
  • Ole Raaschou-Nielsen,
  • Eva Ardanaz,
  • Pilar Amiano,
  • María Dolores Chirlaque López,
  • Matthias B. Schulze,
  • Maria Wennberg,
  • Sophia Harlid,
  • Manon Cairat,
  • Marina Kvaskoff,
  • Inge Huybrechts,
  • Francesca Romana Mancini

Journal volume & issue
Vol. 163
p. 107213

Abstract

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Background: Dioxins and polychlorobiphenyls (PCBs) are persistent organic pollutants that have demonstrated endocrine disrupting properties. Several of these chemicals are carcinogenic and positive associations have been suggested with breast cancer risk. In general population, diet represents the main source of exposure. Methods: Associations between dietary intake of 17 dioxins and 35 PCBs and breast cancer were evaluated in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort from nine European countries using multivariable Cox regressions. The present study included 318,607 women (mean ± SD age: 50.7 ± 9.7) with 13,241 incident invasive breast cancers and a median follow-up of 14.9 years (IQR = 13.5–16.4). Dietary intake of dioxins and PCBs was assessed combining EPIC food consumption data with food contamination data provided by the European Food Safety Authority. Results: Exposure to dioxins, dioxins + Dioxin-Like-PCBs, Dioxin-Like-PCBs (DL-PCBs), and Non-Dioxin-Like-PCBs (NDL-PCBs) estimated from reported dietary intakes were not associated with breast cancer incidence, with the following hazard ratios (HRs) and 95% confidence intervals for an increment of 1 SD: HRdioxins = 1.00 (0.98 to 1.02), HRdioxins+DL-PCB = 1.01 (0.98 to 1.03), HRDL-PCB = 1.01 (0.98 to 1.03), and HRNDL-PCB = 1.01 (0.99 to 1.03). Results remained unchanged when analyzing intakes as quintile groups, as well as when analyses were run separately per country, or separating breast cancer cases based on estrogen receptor status or after further adjustments on main contributing food groups to PCBs and dioxins intake and nutritional factors. Conclusions: This large European prospective study does not support the hypothesis of an association between dietary intake of dioxins and PCBs and breast cancer risk.

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