Patient Weight Can Impact the Effectiveness of Cancer Immunotherapies

Study finds obese patients respond better to treatment.

Obesity is one of the top risk factors for cancer – along with smoking. But obese cancer patients often respond better to immunotherapy than others. Researchers at the University of California Davis (UC Davis) might have found a reason for this.  

Overweight people have weakened immune systems and tend to produce more of the compounds that encourage tumor growth – particularly the PD-1 protein on the surfaces of T cells. These same molecules are the key targets of cancer immunotherapies known as checkpoint inhibitors – making them more effective for many obese patients.

In fact, checkpoint inhibitor therapy can be quite effective, making many different types of tumors disappear for years – but it only works for a limited number of patients, with a disproportionate number of them being overweight.

The UC Davis researchers found that the T cells of obese mice, monkeys, and people were “exhausted” – slow to proliferate and no longer producing proteins that stimulate other immune system compounds – and had more PD-1 protein than average. The excess PD-1 is in part due to greater amounts of leptin, which is present in fat cells. The researchers believe that the leptin triggers a signaling pathway that increases PD-1 on T cells.

Other researchers are now exploring the possibility of incorporating a high-fat diet with checkpoint inhibitor therapy to see if results improve. Such a diet can have negative health consequences overall, however, so a balance must be maintained.


Emilie Branch

Emilie is responsible for strategic content development based on scientific areas of specialty for Nice Insight research articles and for assisting client content development across a range of industry channels. Prior to joining Nice Insight, Emilie worked at a strategy-based consulting firm focused on consumer ethnographic research. She also has experience as a contributing editor, and has worked as a freelance writer for a host of news and trends-related publications