Rare Skin Cancer Linked To Chronic Allergy From Metal Orthopedic Implant

Recent findings published in the Journal of Clinical Investigation have found that in some patients with allergies to metals, they can develop a rare and aggressive form of skin cancer.

As metal alloys help make orthopedic implants stronger and more durable, those who suffer with sensitivity to these metals, which include nickel, cobalt and chromium, can develop chronic inflammation that promotes the development of skin cancers.

Researchers at the Washington University School of Medicine and Barnes-Jewish Hospital in St. Louis, Mo., discovered the condition after a patient who had surgery at another hospital had a metal rode implanted to repair a fractured ankle. Following surgery, the patient developed a skin rash on her ankle, near the location of the implant.

Researchers found that the patient was allergic to nickel in the implant, which led surgeons at the hospital to remove it. However, the rash persisted and developed into a rare form of skin cancer a few years following, known as Marjolin's ulcer.

Furthermore, researchers found that chronic skin inflammation caused by continuous skin contact via allergens contributes to tumor development. The findings show that paitents with metal implants near the skin may need to be monitored for this type of inflammation.

The patient's diagnosis with Marjolin's ulcer, an invasive and potentially deadly squamous cell cancer, surprised physicians. The patient was under 50 years old, and Marjolin's ulcer is extremely rare in people who are young and otherwise healthy. This type of cancer most often is identified in patients with a previous history of skin cancers, but this patient had never had skin cancer.
Researchers studied mouse models to further investigate the issue.

"A contact allergy is a different kind of reaction from allergies to pollen, pet dander or food," said senior author Wayne M. Yokoyama, MD, a Howard Hughes Medical Institute investigator at the School of Medicine, in a news release. "A contact allergy usually develops when an allergen touches the skin or is close to it. Skin rash in response to nickel and poison ivy are two common examples of contact allergies."

To further examine the health issue, researchers examined mouse models exposed to the allergy. 

"This model supported cancer development so strongly that some mice developed invasive squamous cell skin cancers similar to the patient's tumor," said lead study author Shadmehr Demehri, MD, PhD, a dermatologist and postdoctoral fellow.

In order to prevent adverse effects in the future, such as this one, they suggested the potential for allergic reactions to metal implants be asses in patients who have had the implants and in patients preparing to receive them.

"Allergen-free versions of some implants are available," Demehri said. "These versions may cost more or be less durable, but for some patients with sensitivity to metals, they may be the best option."