Background: Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is a growth and differentiation factor used in lumbar spinal fusion. Review of the randomized trials suggested a potential association between rhBMP-2 use and pancreatic cancer.
Objectives: To assess the risk of incident pancreatic cancer among patients exposed to rhBMP-2 compared to those without this exposure during lumbar spinal fusion surgery.
Methods: This was a retrospective cohort study using US Medicare claims data of patients who underwent lumbar fusion surgery between Oct 2003 and Dec 2005. The study population, all >66 y, was identified based on procedure codes for lumbar spinal fusion. We used claims for a bone morphogenetic protein (BMP) on the date of surgery as a proxy for rhBMP-2 exposure (another BMP product shared the same ICD-9-CM code). Our case definition required at least 2 claims listing pancreatic cancer on different dates of service and at least 1 procedure code consistent with cancer-specific therapy. We used Cox proportional hazard regression to determine hazard ratios (HRs) and 95% CIs. Covariates included age, gender, race, and diabetes mellitus.
Results: Of the 93,654 patients in the study, the mean age was 75 y, and 16.5% had claims indicating BMP exposure. During a mean 1.4 years of follow up, 91 patients developed pancreatic cancer (8 in the BMP- and 83 in the non-BMP cohort). Consistent with previous reports, pancreatic cancer was associated with older age, male gender, black race, and diabetes. Compared to those who did not receive BMP, patients exposed to BMP were not at increased risk of pancreatic cancer (adjusted HR¼0.70, 95% CI: 0.34–1.45). A chart review substudy validated the exposure measure; 52/ 55 patients with claims for BMP received rhBMP-2.
Conclusions: In this large study of elderly patients who underwent lumbar fusion surgery, exposure to BMP was not associated with an increased risk of pancreatic cancer.
