Introduction to Skin Cancer
Doctors at the National Institutes of Health have discovered a new cause of skin cancer, according to a case report published Wednesday in the New England Journal of Medicine.
What Causes Skin Cancer
The culprit is a type of human papillomavirus (HPV) that’s regularly found on the skin. It’s long been thought to play a role in the development of skin cancer, but wasn’t believed to be a direct cause.
Skin cancer is caused by DNA damage in skin cells. The most common source of that damage is ultraviolet radiation from the sun. HPV can help UV-damaged DNA build up in cells and turn cancerous. However, in the new case report, doctors found that the virus itself could cause cancerous lesions to form.
The Discovery
The discovery was made in a 34-year-old woman with a weakened immune system; experts said it’s highly unlikely that HPV could play the same role in causing skin cancer in a person with a healthy immune system.
“The virus replicated in a somewhat uncontrolled manner and ended up integrating into the skin cells and once they did that, they became cancerous,” said Dr. Andrea Lisco, section chief of the mucosal and cutaneous viral immunopathogenesis unit at the National Institute of Allergy and Infectious Diseases, part of the NIH. Lisco was the woman’s doctor and also the senior author of the case report.
The Patient’s Condition
The woman had 43 spots of cutaneous squamous cell carcinoma — the second-most common type of skin cancer, after melanoma —on her face, hands and legs. She had surgery to remove the cancers and immunotherapy, but the cancer returned. When Lisco and his team biopsied several of her new tumors, they found that the woman’s skin cancer was being driven by something they hadn’t seen before: a group of HPVs called beta HPV.
About 90% of people carry a strain of beta HPV. Usually, the virus lives on the skin and doesn’t integrate into the DNA of skin cells.
“We shake hands and we pick up those viruses, but if our immune systems are under control, we are fine,” Lisco said.
Types of HPV
It’s a different group of HPV strains — alpha HPVs — that are linked to a range of cancers. Alpha HPVs live on mucus membranes and can integrate into DNA, causing cancers of the cervix, anus, head and neck.
The woman in the case report had a genetic condition that weakened her T-cells (a type of immune cell), leaving her immunocompromised. This allowed the beta HPV living on her skin to behave more like alpha HPV, integrating their DNA into her skin cells and replicating undisturbed, turning the cells cancerous.
Expert Opinion
“You don’t know how much you can directly apply the information from one patient to the wide variety of patients,” said Dr. Anthony Oro, professor of dermatology at Stanford Medicine, who wasn’t involved in the case.
However, “it suggests that, in the event that the T-cell arm of the immune system is not doing its job, beta-type HPV viruses could contribute to skin cancer, and maybe other kinds of cancers as well,” he said.
Treatment and Outcome
The patient needed a stem cell transplant, which replaced her defective T-cells with T-cells that could prevent the HPV from replicating.
“We needed to give this patient a whole new immune system,” Lisco said. It worked. Three years post-transplant, the woman’s skin cancer has not returned.
Conclusion
The discovery of beta HPV as a potential cause of skin cancer in immunocompromised individuals highlights the complex relationship between the immune system and HPV. While the risk of beta HPV causing skin cancer in healthy individuals is low, this finding emphasizes the importance of monitoring immunocompromised patients more closely and taking preventive measures against UV radiation. Further research is needed to understand the role of beta HPV in skin cancer and to explore potential cross-protection from the Gardasil HPV vaccine.
FAQs
Q: What is the new cause of skin cancer discovered by doctors at the National Institutes of Health?
A: The new cause of skin cancer is a type of human papillomavirus (HPV) called beta HPV, which can integrate into the DNA of skin cells and cause cancerous lesions to form.
Q: Is beta HPV a common cause of skin cancer?
A: No, beta HPV is not a common cause of skin cancer in healthy individuals. The risk is higher in immunocompromised individuals.
Q: How can I protect myself from skin cancer caused by beta HPV?
A: You can protect yourself by taking preventive measures against UV radiation, such as wearing sunscreen and covering up your skin from the sun.
Q: Is the Gardasil HPV vaccine effective against beta HPV?
A: The Gardasil HPV vaccine protects against nine strains of alpha HPV, and it is unclear how much cross-protection, if any, it provides against beta HPV.
Q: What is the treatment for skin cancer caused by beta HPV?
A: The treatment for skin cancer caused by beta HPV may involve surgery, immunotherapy, and stem cell transplantation to replace defective T-cells.
