Osteoporosis Drugs Might Not Raise Cancer Risk

April 23 -- WEDNESDAY, April 22 (HealthDay News) -- Two new studies find that the class of osteoporosis drugs known as bisphosphonates may not, in fact, raise the risk of esophageal cancer.

This is in contrast to news earlier this year that the U.S. Food and Drug Administration had received reports of 23 patients taking the oral bisphosphonate Fosamax (alendronate), who had been diagnosed with cancer of the esophagus.

Bisphosphonates have come under scrutiny in recent years for a variety of other possible problems, including an increased risk of atrial fibrillation (a type of abnormal heart rhythm), unusual fractures of the thigh bone, jaw necrosis and inflammatory eye disease.

But the big picture is still unclear, and patients taking the drug, which reduces the risk of fractures related to the bone-thinning condition osteoporosis, should not change their practices, several experts noted.

"The adverse affects reporting agency [where the FDA first heard of the cases] only reports cases but does not look at the science behind it," said Dr. Robert C. Ashton Jr., director of minimally invasive thoracic surgery at Montefiore Medical Center in New York City. "Given the wide use of bisphosphonates and low incidence of esophageal cancer overall, individuals should continue taking them and discuss any concerns with there doctors."

"Don't panic," echoed Dr. Daniel H. Solomon, lead author of one of the new reports being published as a letter-to-the-editor in the April 23 issue of the New England Journal of Medicine. "A series of cases is useful to prompt an epidemiologic study but it should not be used to guide prescribing."

Solomon's analysis of 1,000 patients found no increased risk of esophageal cancer although, he pointed out, the cancer is a rare one, and even this large a study might not have detected a heightened risk.

Solomon and his co-author have received funding from Amgen, a company with a new osteoporosis drug, denosumab, in the pipeline.

Another large study in the same issue of the journal actually found a reduced risk of esophageal cancer among individuals taking bisphosphonates, and no increased risk for gastric cancer, when compared with a much larger control group. There was no overall increased risk when the two types of cancer were grouped together.