Introduction: A number of studies have demonstrated the efficacy of BMP in increasing fusion rates. However, there has been controversy concerning the potential association between use of BMP during spinal fusion surgery and increased risk of cancer. We sought to determine whether use of BMP carried an increased risk of cancer in a national cohort of patients undergoing lumbar fusions.
Methods: Reuter’s MarketScan database was used to identify patients who had lumbar fusion between 2003 and 2009. Of the 94,166 fusions performed, we excluded those with previous diagnosis of cancer and those with less than 2 years of pre- and post-operative follow-up. The association between BMP and cancer risk was independently probed in the total cohort and a propensity matched cohort in which the non-BMP group was designed to closely resemble the BMP patients on a number of parameters related to demographics, insurance type, and comorbidities, among others. The primary outcome was all-type cancer risk at two or more years following operation.
Results: The propensity matched cohort comprised a set of 1344 patients who underwent fusion with BMP and a matched group of 1344 without BMP. In this cohort, the all-type cancer risk was not significantly different (3.20% vs. 2.16%, p = 0.0944). When examining tumor incidence in the total cohort (9367 patients) using a multivariate analysis, there was no significant difference between the two groups except for the diagnosis category “benign neoplasms” (2.60% vs. 1.53%, aOR = 1.489, p = 0.0473). This effect was not evident in the propensity matched cohort (2.60% vs. 1.71%, p = 0.1112).
Conclusions: In a large, independent, propensity matched cohort, the use of BMP in lumbar fusions was not associated with a significant increased cancer risk. BMP was associated with a higher rate of benign neoplasms, however this was not statistically significant after propensity matching.
Patient Care: Since the FDA's approval of BMP for use in anterior lumbar fusions in 2002, the use of BMP has grown considerably. While there are a number of reports demonstrating the efficacy of BMP in increasing the rates of arthrosis, a recent study that examined pooled data from all studies submitted to the FDA found that use of BMP was associated with increased cancer risk. In order to justify the use of BMP, surgeons must not only understand the benefits of its use, but the risks as well. Our current study examines the link between BMP use and cancer risk in an independent, national sample. In this large sample, we found that there was no significant association between use of BMP and overall cancer risk. While we found that BMP use was associated with increased risk of benign neoplasms in the total study cohort, no such association was found in the propensity matched cohort. These findings will improve patient care by providing the surgeon with additional data to inform the decision to use BMP.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand the potential mechanisms through which BMP may affect tumorigenesis, 2)Describe the association between the use of BMP in lumbar fusions and cancer risk, 3) Describe the impact of BMP use on the risk of benign neoplasms in the total and propensity matched cohorts.