BMI can improve chances of cancer survival

Washington: While above average or high BMI (Body Mass Index) is often linked to cancers, diabetes, cardiovascular and other diseases, in some cases the higher level of BMI can improve the chance of survival among certain cancers, suggests new research.

Focusing on clinical trials of atezolizumab, a common immunotherapy treatment for non-small-cell lung cancer (NSCLC), the Australian cancer researchers found improved responsiveness to the drug in those with a high body mass index (BMI). The results of the research were published in the journal JAMA Oncology. The study contrast with regular warnings about the health risks of patients who are overweight and obese.

According to Dr Ganessan Kichenadasse, the lead investigator a medical oncology researcher at the Flinders Centre for Innovation in Cancer, "This is an interesting outcome and it raises the potential to investigate further with other cancers and other anti-cancer drugs."

He added, "We need to do further studies into the possible link between BMI and related inflammation, which might help to understand the mechanisms behind the paradoxical response to this form of cancer treatment."

Previous studies have explored a concept called 'obesity paradox' where obesity is associated with increased risks for developing certain cancers and, counter-intuitively, may protect and give greater survival benefits in certain individuals. "Our study provides new evidence to support the hypothesis that high BMI and obesity may be associated with response to immunotherapy," says Dr Kichenadasse.

The Flinders researchers found NSCLC patients with high BMI (BMI 25 kg/m2) in four clinical trials had a significant reduction in mortality with atezolizumab, apparently benefiting from immune checkpoint inhibitor (ICI) therapy. Treatment options for this form of lung cancer are rapidly evolving and include ICIs, molecular targeted drugs and chemotherapies.

"While our study only looked at baseline and during treatment, we believe it warrants more studies into the potentially protective role of high BMI in other cancer treatments," added the lead author Kichenadasse.

The WHO estimates at least 2.8 million people die each year as a result of being overweight or obese. Overweight and obesity lead to adverse metabolic effects on blood pressure, cholesterol, triglycerides and insulin resistance. Risks of coronary heart disease, ischemic stroke and type 2 diabetes mellitus increase steadily with increasing body mass index (BMI), a measure of weight relative to height.

Of the 1434 participants studied in the Australian research, 49 per cent were of normal weight, 34 per cent were overweight and 7 per cent were obese.