Treatment with intravenous bisphosphonates — drugs used to reduce harm done to bones by cancer or cancer therapy — increases the risk of jaw or facial bone disease or infection, a large-scale comparative study by researchers at the University of Texas Medical Branch at Galveston (UTMB) has found.
Drawing on the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) database linked to Medicare insurance claims, investigators from the UTMB Center for Population Health and Health Disparities compared more than 14,000 cancer patients treated with two types of intravenous bisphosphonates (pamidronate and zoledronic acid) with nearly 27,000 cancer patients who did not receive the drugs. After six years, about 5.5 percent of bisphosphonate users had undergone facial or jaw bone surgery or been diagnosed with inflammation of the jaw bone, compared with 0.3 percent of non-users.
“This study is based on a much larger population than earlier investigations of this phenomenon, and while those studies gave rise to a lot of speculation, this one definitely implies that something serious is going on,” said Gregg S. Wilkinson, professor of preventive medicine and community health at UTMB and lead author of a paper published online June 26 by the Journal of the National Cancer Institute. “We haven’t proven causation, but we found a very strong association between these drugs and disease involving the face and jaw bones.”
Making the connection even stronger, the UTMB researchers also determined that patients who had taken higher doses of the drugs over time were more likely to have experienced jaw and facial bone disease.
“The fact is, we see increased risk depending on the total amount of bisphosphonates received,” Wilkinson said. “The higher the dose, the greater the risk, and the lower the dose, the lower the risk.”
At the same time, Wilkinson cautioned, the overall rate by which the UTMB group determined intravenous bisphosphonates increased the risk of jaw or facial bone disease is rather small, and has to be balanced against the benefits offered by the drugs.
“Intravenous bisphosphonates can produce a much better quality of life for many patients, because when cancer affects the bone the impact can be quite debilitating,” Wilkinson said. “But every drug has side effects. Now doctors and patients can use our data to weigh this one against the good these drugs do.”