A new study has shown that people who take oral bisphosphonates for bone disease over five years may be doubling their risk of developing oesophageal cancer (cancer of the gullet).
Oral bisphosphonates are a type of drug used to treat osteoporosis and other bone diseases and are the most commonly recommended treatment for such conditions.
Researchers from the University of Oxford's Cancer Epidemiology Unit and the Medicines and Healthcare products Regulatory Agency analysed data from the UK General Practice Research Database, which has anonymised patient records for around six million people registered with a NHS GP.
They focused on men and women aged over 40 years - 2,954 with oesophageal cancer, 2,018 with stomach cancer and 10,641 with colorectal (bowel) cancer diagnosed between 1995 and 2005. Each case was compared with five controls matched for age, sex, general practice and observation period.
They found that people with 10 or more prescriptions, or with prescriptions over about five years, had nearly double the risk of oesophageal cancer compared with people with no bisphosphonate prescriptions.
The study has been published on bmj.com.