In this study, the researchers looked at the interaction between obesity and outcomes in patients taking immune checkpoint inhibitors (anti-PD-1 immunotherapy, e.g. nivolumab, pembrolizumab) for the treatment of renal cell carcinoma (RCC).

Seventy-two (72) patients with metastatic RCC were treated with anti–PD-1 immunotherapy (none had been treated with immunotherapy before). Obese patients had poorer progression-free and overall survival. The researchers also looked at some metastatic RCC patients who had not received any treatment and who were scheduled to have a partial or full nephrectomy. In these patients, blood taken from the tumour and a blood vessel in the arm showed decreased amounts of tumour-infiltrating PD-1–high CD8+ T cells in the obese patients. These findings were also shown in mice with RCC where, following anti–PD-1 immunotherapy, obesity reduced the number of mice who responded to treatment (73% lean vs 44% obese).

In this study, the researchers show that obesity is associated with reduced efficacy of anti–PD-1 immunotherapies in RCC. However, the obesity paradox shows that obesity is associated with improved outcomes across several cancers, including RCC. The researchers suggest that interleukin-1β could be involved in the diminished response to immunotherapy in obese patients. These findings need further investigation since they could impact the management of metastatic RCC patients.

Read more in Journal for ImmunoTherapy of Cancer here