Bone medicines may increase risk of esophageal tumours, researchers find

A group of drugs used to prevent bone loss in osteoporosis patients may increase the risk of contracting cancer of the esophagus, a new study found. Patients who took the medicines, known as bisphosphonates, for five years or filled at least 10 prescriptions were twice as likely to be diagnosed with the cancer as those who didn’t, said the study, published today in the British Medical Journal. Drugs in the class of bisphosphonates help maintain bone strength and include Novartis AG’s Reclast, Roche Holding AG’s Boniva and Merck & Co.’s Fosamax. Use of the medicines is associated with inflammation of the esophagus, as well as nausea and heartburn.

The overall risk of cancer is still low, Jane Green, an epidemiologist and the study’s lead author, said in an accompanying statement. “The increased risks we found were in people who used oral bisphosphonates for about five years,” said Green, who works at the University of Oxford’s Cancer Epidemiology unit. “Even if our results are confirmed, few people taking bisphosphonates are likely to develop cancer as a result of taking these drugs.”
The study, which used Britain’s General Practice Research Database, included more than 15,000 cancer patients that it followed for an average of 8 years. The researchers compared prescriptions and patient records. They found that at least one prescription for oral bisphosphonates increased the risk of esophageal cancer by 30 percent and 10 or more prescriptions almost doubled the risk.

The scientists also found no increased risk for cancers of the stomach or colorectum. No Patient Interviews The study contradicts one published last month, which found no connection between the medicines and tumors of the esophagus. This discrepancy may be explained by the longer follow-up period in today’s study and larger control groups, Green said. Because both studies did not interview patients or doctors, they did not validate diagnoses with medical records or check whether drugs were taken according to directions, the researchers said. This year, 16,640 Americans will be diagnosed with cancer of the esophagus, and 14,500 patients will die of the disease, according to the National Cancer Institute. The cancer is treatable, but can rarely be cured, according to the Institute.

**Published by Bloomberg