Bisphoshonates, which are used in the treatment and prevention of osteoporosis, have recently been implicated in the development of oesophageal cancer, however studies report conflicting data.
We conducted a meta-analysis of studies reporting on the association between bisphosphonates and oesophageal cancer to quantify the relationship.
A search was conducted through Medline, PubMed, Embase, and Current Contents Connect to August 2, 2012. We calculated pooled odds ratios and 95% confidence intervals using a random effects model for the risk of oesophageal cancer associated with exposure to bisphosphonates, as well as for the different periods of exposure.
Seven studies, with 19 700 oesophageal cancer cases, met our inclusion criteria. We found a positive relationship between exposure to bisphosphonates and oesophageal cancer, with an odds ratio (OR) of 1.74 with a 95% confidence interval (CI) of 1.19-2.55. Heterogeneity was observed (I2=85%, p<0.001). Publication bias was not present. An increased risk of oesophageal cancer was also found in the group exposed to bisphosphonates for a longer period of time, compared with the group who experienced a shorter period of exposure (OR 2.32; 95% CI 1.57-3.43 versus OR 1.35; 95% CI 0.77-2.39). An increased risk was associated with exposure to Etidronate (OR 1.58; 95% CI 1.12-2.24), but not to Aledronate.
Exposure to bisphosphonates may be associated with an increased risk of oesophageal cancer. More studies are needed to confirm the relationship.