Oral bisphosphonates associated with increased risk for esophageal cancer

Green J. BMJ. 2010;doi:10.1136/bmj.c4444

The risk for esophageal cancer nearly doubled in patients given 10 or more prescriptions for oral bisphosphonates, and the risk associated with the drugs increased over time.

Oral bisphosphonates are the recommended first-line treatment for primary and secondary prevention of osteoporotic fracture. The drugs were not associated with increased risk for gastric or colorectal cancer.

Researchers in the United States and Europe recruited 2,954 patients with esophageal cancer who were matched with 14,721 healthy controls. The mean observation period was 7.5 years.

The mean number of prescriptions for those assigned to fewer than 10 prescriptions was 3.6 vs. 21.6 for those given more than 10 prescriptions. Patients with at least one prescription were at increased risk compared with those who were not prescribed oral bisphosphonates (RR=1.30; 95% CI, 1.02-1.66). The risk was significantly increased for those with 10 or more prescriptions (RR=1.93; 95% CI, 1.37-2.70).

Longer duration of bisphosphonates was similarly associated with an increased risk for esophageal cancer. Researchers segregated patients by duration of bisphosphonate use: less than 1 year, 1 to 3 years and more than 3 years. The mean duration of use for those who used bisphosphonates for more than 3 years was 4.6 years.

Compared with controls, RR for the less than 1 year group was 0.98 (95% CI, 0.66-1.46), 1.12 for 1 to 3 years (95% CI, 0.73-1.73) and 2.24 for 3 years or more (95% CI, 1.47-3.43).

Risk did not vary by bisphosphonate type.