Blood Test Could Provide Clues About Immunotherapy Efficacy

The ratio of immune cells in the blood can determine whether a patient with cancer will respond to immunotherapy.

An experimental blood test can determine whether a patient with cancer will respond to immunotherapy by comparing the 2 types of immune cells, according to a study published by the European Journal of Cancer.

Neutrophils point to signs of chronic inflammation and impaired immunity, while lymphocytes indicate a healthy and functional immune system, according to the study.

“The neutrophil-lymphocyte ratio is widely used by clinicians as a prognostic tool, but until now it was not clear whether this association had utility in predicting patient outcomes on immunotherapies,” said researcher Dr Juanita Lopez.

The ratio of neutrophils to lymphocytes is often high or low in patients with cancer.

Patients with a low ratio of neutrophils to lymphocytes were more likely to respond to treatment with immunotherapy, according to the study.

However, the authors found that patients with a higher ratio of neutrophils to lymphocytes were less likely to respond to PD-1 and PD-L1 inhibitors. These patients had an overall lower survival rate, according to the study.

The authors also looked at the ratio of neutrophils to lymphocytes throughout treatment to determine potential changes. They found that the ratio decreased among patients who responded to treatment.

Notably, the ratio did not change significantly when a patient’s cancer remained stable or progressed further.

“Our research shows that a patient’s initial NLR is a good indication of whether they will benefit from PD-1 or PD-L1 inhibitors and can be used to track a patient’s response throughout their treatment,” Dr Lopez said.

By monitoring the ratio between patient’s neutrophils and lymphocytes, health care providers can determine whether immunotherapy will be effective, according to the study. Providers can also determine the efficacy of immunotherapy through the neutrophil-lymphocyte ratio.

New technology to measure the efficacy of immunotherapy is crucial, as scans alone cannot identify progress of some tumors, according to the authors.

“Biomarkers like these are vital to the development of smarter, kinder treatments, as the sooner clinicians can predict whether a patient will respond to a treatment, the sooner they can move the patient onto an alternative therapy,” Dr Lopez said.