A British study found this week that people who consume a commonly used class of osteoporosis drugs called bisphosphonates for more than five years may be increasing their chances of developing cancer of the gullet or esophagus by two times.

The researchers who conducted the work said that the results were troubling but they should not prompt doctors or patients to immediately change their practice on bisphosphonates, which are mostly prescribed to older people to help strengthen weaker bones.

Jane Green of Oxford University's Cancer Epidemiology Unit, whose research was published in the British Medical Journal said, “We have to be concerned, but this is the first large study with long-term follow up that has found this effect, and it is just one observational study.”

The findings were written in a report: “In Europe and North America, the incidence of esophageal cancer at age 60-79 is typically 1 per 1,000 population over five years, and this is estimated to increase to about 2 per 1,000 with five years' use of oral bisphosphonates.”