Common virus may improve skin cancer treatment outcomes

A new study led by the University of Oxford has revealed that a common and usually harmless virus may positively influence how skin cancer patients respond to current treatments.

Cytomegalovirus (CMV) is a common virus that, while typically asymptomatic, is carried for life by around 50–60% of UK adults. In healthy individuals, CMV is kept in a dormant state by the immune system. However, this process profoundly reshapes how the immune system operates. The study, published in Nature Medicine, explored how CMV affected the immune responses of 341 melanoma patients receiving immunotherapy, a form of cancer treatment that helps harness the immune system to recognize and fight cancer.

Melanoma is a cancer of the skin that can be difficult to cure if not caught early. Immunotherapies have improved the survival rates of melanoma, but not all patients benefit, and some go on to develop resistance. Occasionally, patients develop side effects from immunotherapy (especially those receiving combination treatments), which can be life-changing and, in some cases, fatal.

This research, which is the first of its kind, suggests that CMV infection may improve treatment outcomes in melanoma patients receiving less intensive immunotherapy, while also markedly reducing the frequency of severe side effects. The researchers also found that CMV infection potentially delays melanoma from developing and spreading, indicating that the immune response to CMV might also impact cancer development.

The research team, led by Professor Benjamin Fairfax, Professor of Cancer Immunogenetics at the University of Oxford, found that these effects are likely due to the CMV virus stimulating a group of T cells, immune cells that are crucial in the fight against cancer.

Commenting on the findings, Professor Fairfax said, "Current immunotherapies for cancer can cause serious side effects in some patients, which may occasionally lead to lifelong complications. Prior CMV infection in a patient could help determine, on a patient-by-patient basis, whether immunotherapies are likely to be effective or cause side effects, serving as a key factor in deciding which treatments to give.

"Our work also has potentially fundamental implications for our understanding of skin cancer development, because it shows that factors which influence the immune system independently of cancer can have unanticipated effects on melanoma development."

This is the first time a common virus, unrelated to cancer, has been shown to influence both melanoma development and treatment response. Further research is needed to confirm these findings in larger patient populations and to explore whether CMV-based strategies could be leveraged to enhance the effectiveness of current immunotherapies.

However, these discoveries could open new avenues for personalized immunotherapy approaches, enabling better targeting of drugs to those most in need, and reducing the risk of harmful side effects. The findings also suggest that a patient's viral infection history may be a key factor in predicting treatment success.

This article was originally published on MedicalXpress Breaking News-and-Events.