Measuring T Cell Levels May Help Identify Patient Response to Immunotherapy

A specific immune T cell protects patients with lung cancer.

Measuring the levels of tissue-resident memory T cells may help predict which patients with lung cancer would benefit most from immunotherapy.

Although immunotherapies have made waves in oncology, patients respond differently to treatment, with some who do not respond at all.

Scientists are continuing to search for ways to identify which patients will respond to immunotherapy. The newest research adds to the hunt.

In a study published in Nature Immunotherapy, investigators discovered that patients with lung cancer who had large quantities of tissue-resident memory T cells within their tumors were 34% less likely to die.

The number of cells were not the only cause for the increase in survival, but the behavior of the cells played a key role as well, according to the authors. The cells clustered together in the cancer tissue, “taking up residency” to protect the patient.

Tissue-resident memory T cells also produce additional molecules that attack the tumor. In other words, the immune system may be more likely to target and kill the cancer cells, according to the authors.

“These are hugely exciting results,” said author Christian Ottensmeier. “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.”

Future testing that measures the levels of these T cells could help physicians identify which patients will benefit the most from immunotherapies.

“The immune system can play a powerful role in fighting lung cancer, and this research sheds more light on the interplay between cancer, our immune system, and immunotherapies,” said Dr Justine Alford, senior science information officer at Cancer Research UK. “Cancer Research UK is focusing more research on hard to treat cancers, like lung cancer, where survival has remained stubbornly low. And research like this is crucial to understanding why some people with lung cancer respond well to treatment and, in future, could guide more personalized treatments for patients.”