The Risk of Cancer With the Use of Recombinant Human Bone Morphogenetic Protein in Spine Fusion

STUDY DESIGN.Retrospective cohort study using the Washington State Comprehensive Hospital Abstract Reporting System, the Washington State Cancer Registry, and Washington State death certificates. OBJECTIVE.To study the possible association between recombinant human bone morphogenetic protein (rhBMP) and cancer risk. SUMMARY OF BACKGROUND DATA.The use of rhBMP in spine fusion surgery remains controversial with respect to its possible role in tumorigenesis. METHODS.We compared adults who underwent spine fusion for degenerative disease with and without rhBMP between 2002 and 2010. Patients were matched on the basis of age, sex, and year of treatment. We excluded patients with a diagnosis of cancer prior to or at the index procedure. The primary outcome was the first diagnosis of cancer as identified in the records of the cancer registry. RESULTS.We included 16,914 patients who had spine fusion, of whom 4246 received rhBMP. During the study period, 449 patients received a diagnosis of cancer117 (2.76% of 4246) in the rhBMP group and 332 (2.62% of 12 668) in the no rhBMP group. The incidence rate was similar between the rhBMP and no rhBMP 9.5 and 9.0 per 1000 person years, respectively (hazard ratio, 1.06; 95% CI, 0.86–1.30). There were no differences in the rate of cancer between the two groups in subgroups defined on the basis of site of fusion or surgical method. CONCLUSIONS.There was no increase in overall cancer incidence among those receiving rhBMP. An important limitation of this and other studies of recombinant human bone morphogenetic protein and cancer that have been conducted to date is their relatively limited duration of follow-up. The examination of cancer incidence following rhBMP administration must continue beyond just the first several years in order to adequately assess the potential of rhBMP to influence the occurrence of one or more types of malignancy.Level of Evidence3