According to the National Institutes of Health, osteoporosis affects nearly 10 million Americans, with an additional 34 million at risk for developing the disease. About half of all women and a quarter of men older than 50 will break a bone because of osteoporosis.
Although there is currently no cure for the disease, many of those suffering from osteoporosis find relief in the use of oral bisphosphonates such as Fosamax. These drugs are normally one of the first-line treatments for most osteoporosis patients, as they effectively reduce the risk of fracture and increase bone density.
Currently, more 30 million Americans are taking oral bisphosphonates -- either for osteoporosis or another condition, such as a certain type of bone cancer. Before Merck's patent on Fosamax expired earlier this year, it was the most popularly prescribed drug in this class.
Some doctors said that they fear this report could cause unwarranted fear among patients who are currently taking this osteoporosis medication.
"Every time the media report on some new possible side effect, a lot of patients for whom the benefits of therapy greatly outweigh a true risk ... stop their medication," Siris said.
"I fear patients will conclude that bisphosphonates cause esophageal cancer and there is not enough evidence here to show that," said Dr. Conrad Johnston, a professor in the Department of Medicine at Indiana University.
"We do not know how many people were treated -- probably millions -- [or] what the incidence was in this group and what the expected incidence of esophageal cancer in this age population is," Johnston said. "This could be more, less or the same as expected."
This is not the first time that a study has dealt a blow to the reputation of Fosamax and other oral bisphosphonates.
A study published in April in the Archives of Internal Medicine found that patients taking Fosamax had about an 86 percent increased risk for developing an irregular heartbeat. The study received a huge amount of media attention, despite the fact that much larger studies largely exonerated Fosamax with regard to this side effect.
"You can imagine what that did to the public -- and the number of phone calls we all received from our patients," Siris said.
Siris said that she fears this will be another case in which over-the-top media reports on the inconclusive link between Fosamax and esophageal cancer will scare patients into giving up on a medication that is successfully protecting them from the effects of osteoporosis.
"We need to inform, but we do not need to create major distress based on incomplete data," Siris said.