Body Mass Index Plays a Surprising Role in Immunotherapy's Effectiveness

Body mass index (BMI) might have a positive impact on the outcomes of patients who are taking PD-1 or PD-L1 inhibitors to treat their cancer, according to a recent study conducted by researchers at the University of Oklahoma Health Science Center.

The researchers retrospectively evaluated 198 adult patients who were treated between 2014 and 2017 with anti-PD-1 or PD-L1 immunotherapy agents. Cancer types were divided into four categories: melanoma (25.7 percent), lung cancer (23.5 percent), ovarian cancer (11.5 percent) and other (42.5 percent).

The median age of patients involved was 62 years old, and median follow-up was 272 days. The majority of patients involved (46 percent) were given immunotherapy in the third-line setting or beyond, while 18 percent were given it in the frontline and 36 percent were given it in the second line.

“Obesity has been previously investigated for its role in cancer and promoting tumor growth, at least partially by inducing a chronic inflammatory state,” the authors wrote. “However, it’s unclear how this would play out in the era of immunotherapy, where inflammation has been linked to treatment response.”

The authors’ predictions were right. Higher BMI was significantly associated with better survival outcomes. Patients with BMIs over 30 had an average overall survival (OS) of 236 days, while those with BMIs under 30 had an average OS of 133.

However, the researchers found there was no correlation between obesity and progression-free survival (PFS). Also, when the researchers conducted a multivariate analysis that adjusted for age, performance status, cancer type and line of treatment, there was no association between BMI and OS or PFS.

The researchers said that their findings should pave the way for further research in the future.

“In this single-institution cohort, BMI, unadjusted, was significantly associated with better outcomes in patients receiving anti PD-1/PD-L1 agents. This warrants further investigation of BMI as a prognostic factor,” they wrote.