No Link Between Bisphosphonate Use and Gastrointestinal Cancers

Summary and Comment

In case-control studies, bisphosphonate use of any dose did not confer risk.

Bisphosphonates, used for preventing and treating osteoporosis, can cause irritation of the gastrointestinal (GI) tract. However, whether use of these drugs is associated with excess risk for GI cancers is unclear. Using two large primary care databases, U.K. investigators conducted population-based, case-control studies to assess the association between bisphosphonate use (estimated from prescription data) and risk for GI cancers in older patients (age, 50).
Researchers matched each of 56,000 cases of colorectal, esophageal, or gastric cancer with as many as 5 controls in the same database. Adjusted for multiple confounders, overall bisphosphonate use (1 prescription) was not associated with excess risk for colorectal, esophageal, or gastric cancer in either database. Frequency and duration of bisphosphonate use and bisphosphonate type were not associated with excess cases of colorectal or esophageal cancer. In one database, short-term alendronate use (<1 year) was associated with excess risk for gastric cancer (odds ratio, 1.9), but long-term use was not.
Comment: In this study, bisphosphonate use was not associated with excess risk for GI cancer. However, residual confounding is possible, and bisphosphonate use was estimated from prescription data. As noted by the authors, the association observed between short-term alendronate use and excess risk for gastric cancer is unlikely to be causal, because long-term alendronate use was not associated with excess risk. Overall, these results should be reassuring for patients who take bisphosphonates and for clinicians who prescribe them.
— Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine February 5, 2013

Extract from text

Oesophageal cancer

After adjustment for confounders, both studies showed no significant association between overall bisphosphonate use and risk of oesophageal cancer (adjusted odds ratio 0.97, 95% confidence interval 0.79 to 1.18, for QResearch; and 1.18, 0.97 to 1.43, for CPRD). Similarly, there were no differences for frequency of use or duration (P=1.0 for trend) in QResearch. In CPRD, although odds ratios were progressively higher for longer use of bisphosphonates, none of them nor the trend test reached significance (P=0.07 for trend). There were no significant associations for individual types of bisphosphonate. None of the sensitivity analyses showed any significant associations.

Citation(s):

Vinogradova Y et al. Exposure to bisphosphonates and risk of gastrointestinal cancers: Series of nested case-control studies with QResearch and CPRD data. BMJ 2013 Jan 16; 346:f114. (http://dx.doi.org/10.1136/bmj.f114)

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