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 recognise 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.
Senior author, Professor Ben 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.
Read the full story on Oxford Cancer's website.
Read the journal article here: https://doi.org/10.1038/s41591-025-03647-1