A type of immune cell can help predict which patients may benefit most from cancer immunotherapies, researchers from King’s College London, Guy’s and St Thomas’ Hospital Trust, and the Francis Crick Institute have found.
The study, published today in Nature Cancer, found that a rare type of T cell can help predict whether a patient with advanced skin cancer will be responsive to immunotherapy treatments. The results could also lead to the development of new and more effective treatments for patients with melanoma who do not benefit from current immunotherapies.
When cancer attacks the body, it can target checkpoint proteins on immune cells to weaken the body’s immune response. When this happens, the immune cells that would normally attack cancer cells are considered suppressed and ‘deactivated’, allowing cancers to grow unchecked. One type of immunotherapy treatment, known as immune checkpoint inhibitors (ICIs), can reverse this by blocking the pathways to the checkpoints on T cells.
Previous research has shown that ICIs can ‘reactivate’ T cells formerly suppressed by cancer cells. The T cells can then kill cancer cells by recognising cancer cell mutations not present in healthy cells. Where ICIs have been most successful, doctors treating cancer can seemingly cure some patients with cancer that has spread elsewhere in the body. However, this means most patients with advanced cancers do not benefit from ICIs, added to which the treatments can often cause lifelong side-effects.
Co-senior author Dr Yin Wu, a Wellcome Trust Clinician Scientist at King’s College London and Honorary Consultant Medical Oncologist at Guy’s Hospital, said: “The number of cancer mutations can sometimes help doctors identify the patients most likely to benefit from ICI therapy but curiously, some cancers with very few mutations can still respond very well. Our research team reasoned that these successes must be due to other immune cells that can see cancer cells even in the absence of lots of mutations.”