Bisphosphonate Esophageal Cancer Risk Not Seen in Study

The results of a new study dispute suggestions by some FDA officials that bisphosphonate medications like Fosamax may cause esophageal cancer.  

The study on the risk of esophageal cancer from exposure to Fosamax and other oral bisphosphonates was published in the Journal of the American Medical Association on August 11. Researchers pulled data from a U.K. database and compared those who had esophageal and gastric cancer to those who had been given oral phosphates.

Bisphosphonates are a class of mediations used to strengthen bones and prevent fractures by reducing loss of bone density. The most popular medication in this class is Fosamax (alendronate sodium), which is an oral medication used to treat osteoporosis. Approved in October 1995, Fosamax has been used by more than 20 million people and generated annual sales of more than $3 billion for Merck before it became available as a generic last year.

Esophageal cancer affects the tube between the throat and the stomach. As the tumors grow, symptoms may include difficulty swallowing, loss of weight and coughing blood. An inflammation of the lining of the esophageal tube, known as esophagitis, is a known side effect of Fosamax and other oral bisphosphonates, which often occurs when the drugs are not taken according to directions.

In the latest study, researchers found that people who took bisphosphonates developed gastric or esophageal cancer at the same rate as those who did not, roughly 0.7 per every 1,000 people. The researchers concluded that there was not a significant association between the side effects of bisphosphonate medications like Fosamax and the two forms of cancer. 

The findings contradict concerns raised by FDA officials who believed they were seeing a correlation between Fosamax and esophageal cancer. In a letter to the editor published in the New England Journal of Medicine in January 2009, an FDA drug safety reviewer reported that the agency had received 23 reports of Fosamax esophageal cancer in less than a year, and that another 21 reports of tumors had been filed in Europe and Japan.

Merck faces about 1,000 Fosamax lawsuits over their failure to adequately warn consumers and the medical community about the risk of a serious jawbone condition, known as osteonecrosis of the jaw, which causes portions of the jaw to decay and die. This often results in exposed area of bone inside the mouth and can require surgery to remove portions of the jaw.

In June, a federal jury awarded $8 million in a Fosamax jaw damage lawsuit filed by a woman who developed osteonecrosis of the jaw in 2003 after using the medication for a number of years.