By Lilian Anekwe
Long-term use of oral bisphosphonates can increase the risk of oesophageal cancer, according to an analysis of UK general practice data.
The study by researchers at the University of Oxford and the Medicines and Healthcare products Regulatory Agency found the cancer risk was more than doubled if GPs prescribed the drug to patients for three years or more.
The incidence of oesophageal cancer was 30% higher in people with one or more previous prescriptions for oral bisphosphonates compared with those with no prescriptions.
The relative risk of oesophageal cancer was 90% higher for patients with 10 prescriptions or more than for patients who had taken between one and nine prescriptions.
Taking oral bisphosphonates for more than three years more than doubled the relative risk compared to those who had never been prescribed the drug.
Previous research published in JAMA appeared to rule out a link between bisphosphonates and oesophageal cancer, but the authors of this latest study, published online last week in the BMJ, said their study, which also looked at data included in the General Practice Research Database, had greater statistics, double the observation time and matched five times as many controls.
Professor Jane Green, clinical epidemiologist at the University of Oxford, concluded: ‘If confirmed, an association between use of oral bisphosphonates and risk of oesophageal cancer would add to our knowledge of the risks and benefits of use of oral bisphosphonates. Treatment and prevention of osteoporotic fracture is a subject of increasing public health importance with large scale clinical and economic implications.'
BMJ published online 3 September 2010.Alendronate is one of the most commonly prescribed bisphosphonates