Published 7/1/2008

Setting AAOS Now straight

It was with great interest that I began to read “BMPs and cancer: Is the risk real?” in the May 2008 issue of AAOS Now. It was with tremendous disappointment that I completed it. The article failed to give a thorough overview and explanation of this important issue, neglecting to present important scientific details and not even presenting the most current information. An opportunity to educate orthopaedic surgeons about the actions of these recombinant proteins has been missed.

The article noted “that the use of these products in contraindications is “essentially ‘off-label.’” No government oversight restricts physicians from using products off-label, although it does restrict companies from promoting off-label use and the government is focusing on this. “Off-label” use is common in medicine, particularly orthopaedic surgery, and is defined as any use other than that described in the approved label. This is different than using a product for a use that has been labeled a contraindication, which has implicit increased risk.

When using any growth factor, the potential for carcinogenicity must be considered. From a molecular biology perspective, however, the expression of bone morphogenetic proteins (BMP-2) receptors does not imply that rhBMP-2 is a carcinogen.

I am not advocating the use of any of these proteins during pregnancy or in patients with cancer and have particular concern when the consideration is for placement at the site of an active tumor. It is important, however, for orthopaedic surgeons to understand the biology of these products so that they can make appropriate choices, using risk benefit analysis, to present options to their patients.

Clinical trials in pregnant women or cancer patients are unlikely. Peer-reviewed publications (primarily oral-maxillofacial) have reported on the use [of rhBMP-2] in skeletally immature individuals. Orthopaedic surgeons need to be informed about products with biologic activity to effectively use them in their practices. The AAOS needs to be vigilant in presenting its membership with scientific information.

Yolanda A. Cillo, MD, MBA
Flemington, NJ

Editor’s note: Dr. Cillo’s letter included the disclosure that she was employed by Medtronic until September 2007 and had the opportunity to work with INFUSE® Bone Graft.

AAOS Now is a member newsmagazine, published for the benefit of AAOS fellows. It is not a peer-reviewed journal; research and clinical summaries are presented to inform and encourage readers to pursue topics of interest to them. The article in question was written by members of the Biological Implants Committee to raise awareness, not necessarily to provide a “thorough overview and explanation.”

Correction: In the article “Healthy Bone Team halves hip fracture rate” (June 2008), the T-score used to identify patients with osteoporosis or low bone density should be minus 2 (–2). Additionally, there are 12 HMO centers in southern California.