Drugs used to treat osteoporosis not linked with higher risk of esophageal cancer

The use of oral bisphosphonates did not significantly increase the risk for esophageal or gastric cancers when compared with no bisphosphonate use, according to results of a U.K. study.

Although some reports have suggested a link between the use of oral bisphosphonates and esophageal cancer, an analysis of data from more than 80,000 patients in the United Kingdom found that use of these drugs was not significantly associated with these cancers, the study, published in the August 11 issue of the Journal of the American Medical Association (JAMA), found.

Pooled data

“Esophagitis is a known adverse effect of bisphosphonate use, and recent reports suggest a link between bisphosphonate use and esophageal cancer, but this has not been robustly investigated,” author Chris R. Cardwell, PhD, of Queen’s University Belfast, and colleagues wrote. “Large studies with appropriate comparison groups, adequate follow-up, robust characterization of bisphosphonate exposure, and information on relevant confounders are required to determine whether bisphosphonates increase esophageal cancer risk.”

For the investigation, the researchers pooled data from the U.K. General Practice Research Database to assess the association between oral bisphosphonate use and esophageal and gastric cancers. The analysis included more than 41,000 bisphosphonate users and more than 41,000 nonusers, between 1996 and 2006. Most (81%) were women and the mean age of the overall cohort was 70 years.

During a mean follow-up of 4.5 years for bisphosphonate users, 116 cases of esophageal or gastric cancers (79 esophageal) occurred compared with 115 cases identified in nonusers (72 esophageal) during a mean 4.4 years of follow-up.

Among bisphosphonate users, the overall risk for esophageal cancer was 0.48 per 1,000 person-years compared to 0.44 per 1,000 person-years among nonusers. The combined risk for esophageal and gastric cancer was 0.7 per 1,000 person-years in both groups.

No difference

No difference was observed for the combined risk for esophageal and gastric cancer between either group for any bisphosphonate use, nor was a difference seen for esophageal cancer only.

Risk for either type of cancer also did not differ by duration of bisphosphonate use.

“These drugs should not be withheld, on the basis of possible esophageal cancer risk, from patients with a genuine clinical indication for their use,” the researchers concluded. “Large studies with appropriate comparison groups, adequate follow-up, robust characterization of bisphosphonate exposure and information on relevant confounders are required to determine whether bisphosphonates increase esophageal cancer risk.”

Reference:
Cardwell CR. JAMA. 2010;304(6):657-663.

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