The Impact of Body Mass Index (BMI) on Clinical Outcomes for Patients Receiving Systemic Anti-Cancer Therapies for Advanced Clear Cell Renal Carcinoma

IntroductionObesity is a risk factor for the development of renal cell carcinoma (RCC), however observational studies have suggested patients with RCC receiving systemic anti-cancer therapy (SACT) and BMI ≥25 kg/m² may have a better prognosis than patients with a normal or low BMI, a phenomenon often referred to as the obesity paradox.MethodsThe impact of BMI on survival outcomes in patients with advanced clear cell RCC receiving SACT within the National Health Service (NHS) in England between 2010 and 2018 was investigated. A retrospective analysis was performed using the SACT dataset from NHS-England.ResultsA total of 1034 patients were included. The majority of patients commenced treatment with oral SACT, pazopanib (53.3%) and sunitinib (43.7%). Median overall survival for patients with BMI ≤25 kg/m² was 12.6 months (95% CI; 10.1-14.4) and 17.9 months (15.4-20.0) for patients with BMI ≥25 kg/m² (<i>P</i> < .001). The association between BMI and improved survival was greatest in the first year of commencing SACT with the adjusted mortality rate of 68.9% for patients with BMI less than 25 kg/m² compared to 48.6% for patients with BMI greater than 25 kg/m² (rate ratio .77, .63 to .93).ConclusionA high BMI compared to a normal or low BMI was associated with improved survival in patients with metastatic RCC who were predominantly treated with oral SACT. Improved survival in obese patients with advanced RCC may be associated with improved response to systemic targeted therapies.