It’s well-known that obesity is a risk factor for cardiovascular disease. But some research suggests that while people who are obese are more likely to develop cardiovascular problems, they’re also less likely to die from them. This counterintuitive finding is called the “obesity paradox”.
Thomas Jefferson University researchers wanted to see if the obesity paradox also applied to cancer. Their research suggests that obese patients fare better after immunotherapy treatment for solid tumors.
The study included data from over 18,000 cancer patients from the TriNetX healthcare database, half of whom were obese. The researchers compared survival rates after immunotherapy between obese patients and those with normal body mass index (BMI).
“We found that patients who were obese had improved overall survival almost across the board,” says Eric Mastrolonardo, MD, a 4th-year otolaryngology resident at Jefferson Health and first author on the paper.
“The study provides some evidence that obesity can be associated with improved responsiveness to immunotherapy,” says Joseph Curry, MD, Vice Chairman of Research at Thomas Jefferson University and the senior author on the study. “This finding is intriguing, but more research is required to understand why it might be.”
There are several theories concerning obesity’s role in immunotherapy effectiveness, including improved nutritional status or increased immune reserve. Past research in mice has proposed that obesity may be associated with better outcomes because obesity causes certain proteins to be expressed at higher levels, so immunotherapy drugs that affect those proteins have a more dramatic effect. However, this theory hasn’t been tested in humans. Continuing to tease apart why some people respond better to immunotherapy will be key to improving cancer treatment in the coming years.
“The advent of anti-cancer immunotherapy has been one of the most important cancer advances in recent decades, but only a fraction of patients actually respond,” Dr. Curry says. “We hope that this work points researchers towards new translational research and clinical trials, which can then be used to find ways to increase the number of patients who benefit from immunotherapy for cancer.”
By Marilyn Perkins
Journal
Cancer