Oral bisphosphonates increase risk of esophageal but not other cancers

Using oral bisphosphonates for the treatment of osteoporosis for at least 5 years approximately doubles the incidence of esophageal cancer per 1,000 population, according to a recent nested case-control analysis from researchers in the United Kingdom.

Using a primary-care cohort of about 6 million people with prospectively recorded information on bisphosphonate prescriptions, researchers found that patients who have taken 1 or more prescriptions for oral bisphosphonates are at about 30% greater risk for developing esophageal cancer than those who have never taken the drugs (relative risk [RR], 1.30; 95% confidence interval [CI], 1.02-1.66; P=.02). Those who have taken 10 or more prescriptions (RR, 1.93; 95% CI, 1.37-2.70) have about twice the risk of those who have taken 1 to 9 prescriptions (RR, 0.93; 95% CI, 0.66-1.31; P for heterogeneity=.002).

Similarly, use of oral bisphosphonates for longer than 3 years (on average, about 5 years) compared with no use was associated with an RR of 2.24 (95% CI, 1.47-3.43). Risk for esophageal cancer did not differ significantly by bisphosphonate type, and risk in those with 10 or more bisphosphonate prescriptions did not vary by age, sex, smoking, alcohol intake, or body mass index; by diagnosis of osteoporosis, fracture, or upper gastrointestinal disease; or by prescription of acid suppressants, nonsteroidal anti-inflammatory drugs, or corticosteroids.

Green J, Czanner G, Reeves G, Watson J, Wise L, Beral V. Oral bisphosphonates and risk of cancer of oesophagus, stomach, and colorectum: case-control analysis within a UK primary care cohort. BMJ. 2010;341:c4444.