Urine cytology screening of French workers exposed to occupational urinary tract carcinogens: a prospective cohort study over a 20-year period

BMJ Open. 2017 Sep 21;7(9):e016238. doi: 10.1136/bmjopen-2017-016238.

Abstract

Objectives: To demonstrate that urine cytology screening can provide relevant epidemiological data for earlier detection of urothelial cancer caused by occupational exposure.

Design: Prospective cohort study.

Setting: Industries using urothelial carcinogens in France. Urine samples were collected on site, after a work week and were analysed at the University Hospital of Clermont-Ferrand, France.

Participants: Participants were workers exposed to urothelial carcinogens. Women and current smokers at time of study recruitment were exclusion criteria.

Outcomes: Urine cells atypia were ranged into three classes: negative/normal, atypical/suspicious/dysplasia or positive/malignant.

Results: We included 2020 workers over a period of 20 years from 1993 to 2013: 606 worked in rubber manufacturing, 692 from metal processing, 245 in chemical industry and 477 in roadwork and building industry. Workers had a mean exposure of 15.2±10.4 years before their first urine cytology screening. There was a mean of 3.4±4.3 urine cytology screenings per worker between 1993 and 2013. 6478 cytology were normal, 462 suspicious and 13 malignant. Suspicious and malignant cytology occurred in 4.8% of workers exposed for 1-10 years, 6.2% for 11-20 years of exposure, 7.6% for 21-30 years and 8.6% for >30 years (p<0.001). Using exposure for 1-10 years as reference, the adjusted OR of receiving a suspicious or malignant diagnosis increased with duration of exposure: OR=1.50 (95% CI 1.10 to 2.05, p=0.01) for 21-30 years and OR=1.78 (95% CI 1.23 to 2.56, p=0.002) for >30 years of exposure. Using metal processing as reference, the risk of pathological urine cytology results increased for rubber manufacturing (OR=1.32, 95% CI 1.05 to 1.65, p=0.02), with a trend for roadwork and building industry (OR=1.39, 95% CI 0.98 to 1.97, p=0.07) and for chemical industry (OR=1.34, 95% CI 0.94 to 1.93, p=0.11).

Conclusions: Urine cytology is a useful tool in occupational medicine. We promote new guidelines with an early screening of urothelial cancer by cytology, starting with beginning of exposure.

Keywords: biomarker; bladder; cancer; epidemiology; work.

MeSH terms

  • Adult
  • Early Detection of Cancer / methods*
  • Female
  • France / epidemiology
  • Humans
  • Logistic Models
  • Male
  • Manufacturing Industry / classification
  • Manufacturing Industry / statistics & numerical data*
  • Middle Aged
  • Multivariate Analysis
  • Occupational Exposure / analysis
  • Occupational Exposure / statistics & numerical data*
  • Prospective Studies
  • Time Factors
  • Urine / cytology*
  • Urologic Neoplasms / diagnosis*
  • Urologic Neoplasms / epidemiology*