Eighty-nine and 92 cases of esophageal cancer were reported in the bisphosphonate and control groups, respectively, as were 49 and 57 cases of stomach cancer -- a negligible difference.

CNN: Study: No esophageal cancer risk from bone drugs

The researchers had no way of verifying how many patients actually filled -- and took -- their bisphosphonate prescriptions, and they had incomplete information on the participants' other potential risk factors for cancer, such as smoking and body weight.

CNN: Study: No esophageal cancer risk from bone drugs