Skip to nav Skip to content

About 20% of patients with non-small cell lung cancer respond to immunotherapy treatment. So, why don’t the other 80%?

A team of researchers and physicians at Moffitt Cancer Center began investigating the gut microbiome — or all the microorganisms that live in your digestive tract — to determine if there is a relationship between the gut and immune response in advanced cancers. 

During the observational study, researchers discovered a trend between nutritional status and treatment response. Patients who were malnourished, who also tend to have an adverse gut microbiome, had poorer outcomes. The study’s results were presented at the American Association for Cancer Research annual meeting.

Dr. Lary Robinson, thoracic surgeon

Lary Robinson, MD

“We saw a very strong correlation between patients who were nutritionally depleted and had lost some weight; their chances of responding to immunotherapy was very poor,” said Lary Robinson, MD, surgeon in the Department of Thoracic Oncology and lead author of the study. “Nutrition is unfortunately not regarded very highly by most physicians. It’s not talked about much, it’s sort of the elephant in the room.”

Malnutrition is present in 15% to 40% of cancer patients and is most likely caused by inflammation that promotes weight loss. Weight loss impairs tolerance and response to most cancer treatment, including immunotherapy which relies on a robust immune system.

In the study, patients who responded to immunotherapy had progression-free survival of almost 16 months, compared with patients who didn’t respond — many who were malnourished — and had a progression-free survival of less than three months.

“This tells us we need to consider if there’s something we can do beforehand like ‘pre-habilitation’ before treatment starts,” Robinson said. “Can we do something in the few weeks before for nutrition that would improve response to immunotherapy?”

Robinson says the easiest way to identify which patients are malnourished is to perform the Mini Nutritional Assessment prior to treatment. The screening tool gives patients a score based on things like recent weight loss, eating patterns, mobility and psychological stress. Patients whose score points to malnutrition should be promptly referred to nutritional counseling.

“Getting patients ready for treatment needs to play a bigger role,” Robinson said. “This also gives patients some control, something they can do proactively to improve their status. I think there is a lot of enthusiasm of, ‘I can play a role in my treatment, and I can improve my chances of having a positive response.’”