Biological Implications of Obesity Linked to Survival of Patients With Renal Cell Carcinoma

Downregulated FASN gene expression, which is associated with higher body mass index (BMI), may improve the overall survival of patients with metastatic renal cell carcinoma (RCC), according to an article published in the Journal of Clinical Oncology.¹

To evaluate the role of obesity in RCC prognosis, researchers enrolled 1975 patients using data from the International Metastatic Renal Cell Carcinoma Database Consortium (IMDC); 1190 were obese, and 785 were normal or underweight. Obesity was defined as a BMI greater than or equal to 25 kg/m².

Whether a patient’s weight fluctuated between obese and normal was not evaluated.

Overall survival of patients registered in the IMDC was 25.6 months for obese patients, and 17.1 months for normal and underweight patients. Analyses of all patient groups evaluated by the researchers were consistent with this trend.

FASN gene expression was lower among obese patients, possibly accounting for this trend. Fatty acid synthase-positive patients also had a greater overall survival.

The authors conclude that patient obesity, which is associated with downregulated FASN gene expression and likelihood to be fatty acid synthase-positive, is linked to likelihood of survival with RCC. These findings may lead to improved targeted therapy in this setting.

Several study flaws are noted, including the dichotomized BMI scale and lack of metabolic biomarkers.

Reference 

1. Albiges L, Hakimi AA, Xie W, et al. Body mass index and metastatic renal cell carcinoma: clinical and biological correlations. J Clin Oncol. 2016 Sep 6. doi: 10.1200/JCO.2016.66.7311 [Epub ahead of print]