Diet linked to success in immunotherapy for melanoma

For the first time, researchers have discovered a link between diet patterns and how well a patient responds to immunotherapy – the main treatment when melanoma spreads in the body.

The study, published in Nature Medicine, involved 218 melanoma patients from Australia, the Netherlands and the United States.

High-risk patients received immunotherapy before their cancer was surgically removed.

“We have known for some time that the microbiome of the gut shapes a patient’s response to immunotherapy, however we haven’t known what role diets plays in that,” Rebecca Simpson, Melanoma Institute Australia PhD student and study investigator, said.

Researchers examined the dietary patterns of patients and stool samples were collected to profile their gut bacteria.

The study showed that lower fibre and omega-3 fatty acid consumption was linked to a poorer response to immunotherapy.

“The greater the diversity of the zoo in your gut, the better off you are in terms of responding to immunotherapy but what we’ve done is linked diet to that zoo,” Professor Georgina Long, Co-Medical Director at the Melanoma Institute Australia, said.

Clinical trials are now needed to see whether boosting or changing someone’s diet will make a difference in patient outcomes, including the risk of side effects.

Immunotherapy has revolutionised the treatment of advanced diseases including high-risk early-stage melanoma.

In melanoma patients whose cancer has spread to other parts of the body, it has been a lifeline.

“Those patients used to survive only a few months over a decade ago. Now we have long term durable survival in over 50 per cent of patients,” Long said.

Gut bacteria and dietary patterns are some of the lines of investigation researchers are pursuing to help broaden the use of treatment.

“I think it’s important to note that the gut microbiome is only one of many factors which influence response to treatment,” Simpson said.