Objective: In addition to their well-known osteogenic properties, bone morphogenetic proteins (BMPs) have developmental and regenerative roles that may impact tumorigenesis and promote tumor spread. Given that the most common site of tumor metastases to bone is the spine, determining whether BMPs can be linked to cancer is of particular relevance to surgeons treating primary or metastatic spinal disease. This article reviews the basic scientific and clinical background of BMPs and their potential role in promoting cancer.
Methods: A literature review to identify studies relating to BMP and tumorigenesis was conducted. Databases evaluated included MEDLINE and EMBASE as well as the Cochrane Controlled Trials Register through 2008.
Results: Bone morphogenetic proteins are a diverse class of molecules belonging to the transforming growth factor-beta superfamily that serve a variety of biologic functions. Bone morphogenetic proteins have critical roles in stem and progenitor cell biology as regulators of cellular expansion and differentiation. Transforming growth factor-beta and related cell signaling pathways as well as stem and progenitor cell signaling have been linked to cancer. Multiple in vitro and in vivo studies suggest a significant role of BMPs in promoting tumorigenesis and metastasis. However, there are also comparable studies that imply that BMPs may have a negative effect on cancer.
Conclusion: There is no definitive association between BMPs and the promotion of tumorigenesis or metastasis. However, given the relatively large number of studies reporting a positive effect of BMPs on tumorigenesis or metastasis, the use of BMPs in patients with primary or metastatic spinal tumors should be carefully considered.