Cancer risk in persons receiving prescriptions for paracetamol: A Danish cohort study

Authors

  • Søren Friis,

    Corresponding author
    1. Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark
    • Institute of Cancer Epidemiology, Danish Cancer Society, Strandboulevarden 49, DK-2100 Copenhagen, Denmark
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    • Fax: +45-35-25-77-34

  • Gunnar Lauge Nielsen,

    1. Department of Clinical Epidemiology, Aarhus University Hospital and Aalborg Hospital, Aarhus and Aalborg, Denmark
    2. Department of Medicine and Gastroenterology M, Aalborg Hospital, Aalborg, Denmark
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  • Lene Mellemkjær,

    1. Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark
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  • Joseph K. McLaughlin,

    1. International Epidemiology Institute, Rockville, MD, USA
    2. Department of Medicine, Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
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  • Ane Marie Thulstrup,

    1. Department of Clinical Epidemiology, Aarhus University Hospital and Aalborg Hospital, Aarhus and Aalborg, Denmark
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  • William J. Blot,

    1. International Epidemiology Institute, Rockville, MD, USA
    2. Department of Medicine, Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
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  • Loren Lipworth,

    1. International Epidemiology Institute, Rockville, MD, USA
    2. Department of Medicine, Vanderbilt University Medical Center, Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
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  • Hendrik Vilstrup,

    1. Department of Medicine V (Hepatology and Gastroenterology), Aarhus University Hospital, Aarhus, Denmark
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  • Jørgen H. Olsen

    1. Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark
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Abstract

The use of paracetamol has been associated with increased risks for urinary tract cancers and decreased risk for ovarian cancer, although results have been inconsistent. We conducted a population-based cohort study using data from the Prescription Database of North Jutland County and the Danish Cancer Registry. Cancer incidence among 39,946 individuals receiving prescriptions for paracetamol was compared with expected incidence based on the North Jutland population who did not receive paracetamol prescriptions, during a 9-year follow-up period. Standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (95% CIs) were calculated for cancers overall and at selected sites. Overall, 2,173 cancers were observed with 1,973 expected, yielding a SIR of 1.10 (95% CI, 1.06–1.15). Significantly elevated SIRs were found for cancers of the esophagus (1.9; 95% CI, 1.3–2.8) and lung (1.6; 95% CI, 1.4–1.7). Nonsignificantly increased SIRs were observed for cancers of the liver (1.5; 95% CI, 0.96–2.2), renal parenchyma (1.3; 95% CI, 0.9–1.7) and renal pelvis/ureter (1.6; 95% CI, 0.96–2.6), whereas the SIR for cancer of the urinary bladder was close to unity (1.1; 95% CI, 0.9–1.4). For ovarian cancer, the SIR was close to expectation (0.9; 95% CI, 0.6–1.2) with no evidence of trends with duration of follow-up or number of prescriptions. A similar risk pattern was observed after exclusion of person-time experience following prescription for aspirin or other nonsteroidal antiinflammatory drugs in the study cohort and reference population. Our results do not support a major role for paracetamol in the development of cancers of the urinary tract, and we found little evidence of a protective effect of paracetamol against ovarian cancer. The elevated risks for cancers of the esophagus, lung and liver are most likely a result of confounding variables, but may warrant further investigation. © 2002 Wiley-Liss, Inc.

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