Skin-Dwelling HPV Triggers Cancer in Weakened Immune Systems

Researchers at the National Institutes of Health (NIH) have made a surprising discovery about the cause of skin cancer in people with weakened immune systems. In a case report published in the New England Journal of Medicine, doctors found that a type of human papillomavirus (HPV) commonly found on the skin can directly trigger the development of skin cancer.

The case involves a 34-year-old woman with a genetic condition that left her immunocompromised. Over time, she developed 43 cancerous lesions on her face, hands, and legs. Biopsies revealed that the woman's skin cancer was being driven by a group of HPV strains called beta HPV, which had integrated into her skin cells and caused them to become cancerous.

Typically, beta HPV lives harmlessly on the skin, and the immune system keeps it in check. However, the woman's weakened immune system allowed the virus to replicate unchecked and integrate into her skin cells, turning them cancerous. This is in contrast to the better-known alpha HPV strains, which are linked to cancers of the cervix, anus, and head and neck.

To treat the woman's condition, doctors performed a stem cell transplant, which replaced her defective immune cells with healthy ones. Three years later, the woman's skin cancer has not returned, demonstrating the importance of a robust immune system in preventing HPV-driven skin cancer.

This discovery challenges the previous understanding that HPV only passively contributes to skin cancer by helping UV radiation damage skin cells. It suggests that in certain cases, the virus itself can directly cause cancerous changes, especially in people with weakened immune systems.