Tetrachloroethylene exposure and bladder cancer risk: a meta-analysis of dry-cleaning-worker studies

TY - JOUR

T1 - Tetrachloroethylene exposure and bladder cancer risk

T2 - a meta-analysis of dry-cleaning-worker studies

AU - Vlaanderen, Jelle

AU - Straif, Kurt

AU - Ruder, Avima

AU - Blair, Aaron

AU - Hansen, Johnni

AU - Lynge, Elsebeth

AU - Charbotel, Barbara

AU - Loomis, Dana

AU - Kauppinen, Timo

AU - Kyyronen, Pentti

AU - Pukkala, Eero

AU - Weiderpass, Elisabete

AU - Guha, Neela

PY - 2014/7

Y1 - 2014/7

N2 - BACKGROUND: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as "probably carcinogenic to humans" based on limited evidence of an increased risk of bladder cancer in dry cleaners.OBJECTIVES: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry.METHODS: Random-effects meta-analyses were carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure-response data because of the limited number of studies available.RESULTS: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI: 0.82, 1.42; three studies; 463 exposed cases). For employment as a dry cleaner, the overall mRR was 1.47 (95% CI: 1.16, 1.85; seven studies; 139 exposed cases), and for smoking-adjusted studies, the mRR was 1.50 (95% CI: 0.80, 2.84; 4 case-control studies).CONCLUSIONS: Our meta-analysis demonstrates an increased risk of bladder cancer in dry cleaners, reported in both cohort and case-control studies, and some evidence for an exposure-response relationship. Although dry cleaners incur mixed exposures, tetrachloroethylene could be responsible for the excess risk of bladder cancer because it is the primary solvent used and it is the only chemical commonly used by dry cleaners that is currently identified as a potential bladder carcinogen. Relatively crude approaches in exposure assessment in the studies of "tetrachloroethylene-exposed workers" may have attenuated the relative risks.

AB - BACKGROUND: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as "probably carcinogenic to humans" based on limited evidence of an increased risk of bladder cancer in dry cleaners.OBJECTIVES: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry.METHODS: Random-effects meta-analyses were carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure-response data because of the limited number of studies available.RESULTS: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI: 0.82, 1.42; three studies; 463 exposed cases). For employment as a dry cleaner, the overall mRR was 1.47 (95% CI: 1.16, 1.85; seven studies; 139 exposed cases), and for smoking-adjusted studies, the mRR was 1.50 (95% CI: 0.80, 2.84; 4 case-control studies).CONCLUSIONS: Our meta-analysis demonstrates an increased risk of bladder cancer in dry cleaners, reported in both cohort and case-control studies, and some evidence for an exposure-response relationship. Although dry cleaners incur mixed exposures, tetrachloroethylene could be responsible for the excess risk of bladder cancer because it is the primary solvent used and it is the only chemical commonly used by dry cleaners that is currently identified as a potential bladder carcinogen. Relatively crude approaches in exposure assessment in the studies of "tetrachloroethylene-exposed workers" may have attenuated the relative risks.

KW - Humans

KW - Laundering

KW - Occupational Exposure

KW - Risk Assessment

KW - Solvents

KW - Tetrachloroethylene

KW - Urinary Bladder Neoplasms

U2 - 10.1289/ehp.1307055

DO - 10.1289/ehp.1307055

M3 - Review

C2 - 24659585

SN - 0091-6765

VL - 122

SP - 661

EP - 666

JO - Environmental Health Perspectives

JF - Environmental Health Perspectives

IS - 7

ER -