Scientists from the UK and US say they have identified a new type of immune cell that could be able to predict which lung cancer patients will benefit most from treatment with an immunotherapy.

The study, funded by Cancer Research UK and published in Nature Immunotherapy, showed that lung cancer patients with a high level of tissue-resident memory T-cells in their tumour were 34 percent less likely to die.

Researchers at the University of Southampton and La Jolla Institute for Allergy & Immunology, California, also discovered that the cells’ behaviour also contributed to increased survival, as they clustered together and ‘took up residency’ in the cancer tissue to protect the patient.

Furthermore, these new T-cells also produce other molecules that attack the tumour, which could make the cancer more visible to the body’s immune system.

It is hoped that, in future, testing for levels of these cells could help doctors identify which patients will benefit most from immunotherapies such as Bristol-Myers Squibb’s Opdivo or MSD’s Keytruda, that help to boost the body’s ability to fight the cancer.

Also, the researchers believe the T-cell could be used as a template to develop a vaccine to boost immunotherapy even further.

“These are hugely exciting results,” said Professor Christian Ottensmeier, Cancer Research UK scientist at the University of Southampton.

“For the first time we have a real indication of who might benefit from a particular drug before we make treatment decisions. So far when we use immunotherapy we do not know if a patient will benefit. The new findings are a big step towards making this exciting treatment much more predictable.

“Our results will also make the treatment pathway more reassuring for our patients. And if we can translate our finding into clinical practice, then we will also save patients unnecessary side effects and reduce costs to the NHS.”

Around 35,600 people die from lung cancer each year in the UK, making it the most common cause of cancer death in the UK.