Osteoporosis patients taking oral bisphosphonate drugs for long periods of time may have higher risks of esophageal cancer, says a new study conducted by Dr. Jane Green of the University of Oxford in England and colleagues.
The study involved some 80,000 patients monitored for over seven years on average, and came out with deduction that patients on long-term use of oral bisphosphonate drugs might be more prone to cancer development, reports ABC News.
"Our study ... had the potential to include people with longer durations of bisphosphonate use and also had greater statistical power," Green and colleagues said.
Green and colleagues tracked medical records of 2,954 esophageal cancer patients, 2,018 stomach cancer patients, and 10,641 patients suffering from colon cancer, in addition to controls for each case matched with age, sex, pre-diagnosis observation time, and practice location.
While earlier studies had not found any links between cancer and oral bisphosphonates, Dr. Green reported that esophageal cancer patients were 1.93 times likely to have taken at least ten prescriptions for these drugs.
Diane Wysowski, an epidemiologist with the U.S. Food and Drug Administration, also mentioned in her editorial that links between esophageal cancer and oral bisphosphonates had been suggested for over 15 years.
Though systematic research in the context of the proposed links has been prompted, the FDA has not ordered label warnings as yet.
About 3.1 percent of the esophageal cancer patients had received at least one bisphosphonate prescription before diagnosis, compared with 2.4 percent of the controls over a similar period. The analysis showed similarity of rates in bisphosphonate use in the patients of stomach and colon cancer, relative to controls.
Though, in the esophageal cancer patients, the relationship with bisphosphonate use appeared to increase with the number of prescriptions and with long-term use.
But the researchers have pointed out that while the links between the drug and cancer is likely, there is a possibility “that the associations observed reflect other, unknown, factors that are linked to prolonged use of bisphosphonates and that also increase the risk of esophageal cancer."
