Scandinavian Journal of Work, Environment & Health (May 2017)

Shift work and colorectal cancer risk in the MCC-Spain case–control study

  • Kyriaki Papantoniou,
  • Gemma Castaño-Vinyals,
  • Ana Espinosa,
  • Michelle C Turner,
  • Maria Henar Alonso-Aguado,
  • Vicente Martin,
  • Nuria Aragonés,
  • Beatriz Pérez-Gómez,
  • Benito Mirón Pozo,
  • Inés Gómez-Acebo,
  • Eva Ardanaz,
  • Jone M Altzibar,
  • Rosana Peiro,
  • Adonina Tardon,
  • José Andrés Lorca,
  • Maria Dolores Chirlaque,
  • Andrés García-Palomo,
  • Jose Juan Jimenez-Moleon,
  • Trinidad Dierssen,
  • Maria Ederra,
  • Pilar Amiano,
  • Marina Pollan,
  • Victor Moreno,
  • Manolis Kogevinas

DOI
https://doi.org/10.5271/sjweh.3626
Journal volume & issue
Vol. 43, no. 3
pp. 250 – 259

Abstract

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OBJECTIVES: Shift work that involves circadian disruption has been associated with a higher cancer risk. Most epidemiological studies to date have focused on breast cancer risk and evidence for other common tumors is limited. We evaluated the risk for colorectal cancer (CRC) in relation to shift work history in a population-based case–control study in Spain. METHODS: This analysis included 1626 incident CRC cases and 3378 randomly selected population controls of both sexes, enrolled in 11 regions of Spain. Sociodemographic and lifestyle information was assessed in face-to-face interviews. Shift work was assessed in detail throughout lifetime occupational history. We estimated the risk of colon and rectal cancer associated with rotating and permanent shift work (ever, cumulative duration, age of first exposure) using unconditional logistic regression analysis adjusting for potential confounders. RESULTS: Having ever performed rotating shift work (morning, evening and/or night) was associated with an increased risk for CRC [odds ratio (OR) 1.22, 95% confidence interval (95% CI) 1.04–1.43], as compared to day workers. Having ever worked permanent night shifts (≥3 nights/month) was not associated with CRC risk (OR 0.79, 95% CI 0.62–1.00). OR increased with increasing lifetime cumulative duration of rotating shift work (P-value for trend 0.005) and were highest among subjects in the top quartiles of exposure (3^rd quartile, 20–34 years, OR 1.38, 95%CI 1.06–1.81; 4^th quartile, ≥35 years, OR 1.36, 95% CI 1.02–1.79). CONCLUSIONS: These data suggest that rotating shift work may increase the risk of CRC especially after long-term exposures.

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