Exposure to bisphosphonates and risk of colorectal cancer

A population-based nested case-control study

Authors

  • Harminder Singh MD, MPH,

    Corresponding author
    1. Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
    2. University of Manitoba Inflammatory Bowel Disease Clinical and Research Center, Winnipeg, Manitoba, Canada
    3. Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
    • 805-715 McDermot Avenue, Winnipeg, Manitoba, Canada R3E3P4
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    • Fax: (204) 789-3972

  • Zoann Nugent PhD,

    1. Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
    2. University of Manitoba Inflammatory Bowel Disease Clinical and Research Center, Winnipeg, Manitoba, Canada
    3. Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
    4. Epidemiology and Cancer Registry, CancerCare Manitoba, Winnipeg, Manitoba, Canada
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  • Alain Demers PhD,

    1. Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
    2. Epidemiology and Cancer Registry, CancerCare Manitoba, Winnipeg, Manitoba, Canada
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  • Salaheddin Mahmud MD, PhD,

    1. Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
    2. Epidemiology and Cancer Registry, CancerCare Manitoba, Winnipeg, Manitoba, Canada
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  • Charles Bernstein MD

    1. Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
    2. University of Manitoba Inflammatory Bowel Disease Clinical and Research Center, Winnipeg, Manitoba, Canada
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  • Dr. Bernstein holds the Bingham Chair in Gastroenterology.

Abstract

BACKGROUND:

Chemoprevention is a potentially attractive strategy for decreasing the burden of colorectal cancer (CRC). Preclinical studies suggest that bisphosphonates (BPs) may have direct antitumour effects against CRC. The objective of this study was to determine the effect of exposure to BPs on the incidence of CRC.

METHODS:

The Manitoba Cancer Registry was used to identify patients who were diagnosed with CRC from 2000 to 2009 who had been living in Manitoba for at least 5 years before diagnosis (cases). Each case was matched to 10 controls of similar age, sex, and duration of residence in Manitoba using incidence density sampling. Exposure to BPs was determined using the provincial Drug Program Information Network database. Conditional logistic regression analysis was performed to determine the effect of exposure to BPs on CRC incidence with adjustment for health care use, medical procedures (including lower gastrointestinal endoscopy), socioeconomic status, and pre-existing health conditions.

RESULTS:

In total, 5425 patients with CRC were matched to 54,242 controls. In the multivariate analysis, exposure to BPs was associated with a reduction in the risk of CRC (2-13 BP prescriptions over ≥5 years: odds ratio [OR] 0.84; 95% confidence interval [CI], 0.71-1.00; ≥14 BP prescriptions over ≥5 years: OR, 0.78; 95% CI, 0.65-0.94). When the effect of specific BP agents was evaluated, the effect was significant only for exposure to risedronic acid (OR, 0.50; 95% CI, 0.30-0.85). There was no significant effect of increasing duration or cumulative dose of alendronic acid.

CONCLUSIONS:

The results from this study suggested that exposure to BPs, especially risedronic acid, may be associated with a decreased risk of developing CRC. Cancer 2012;. © 2011 American Cancer Society.

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