To investigate impact of body mass index (BMI) on survival across different histologies and stages of renal cell carcinoma (RCC).
We conducted a retrospective multicenter analysis of clear cell (ccRCC) and non-ccRCC. Obesity was defined according to the WHO criteria (non-Asian BMI >30 Kg/m2, Asian BMI >27.5 Kg/m2). Multivariable analysis (MVA) via Cox regression model was conducted for all-cause (ACM), cancer-specific mortality (CSM) and recurrence.
A total of 3,880 patients with a median follow-up of 31 (IQR 9-64) months were analyzed. Overall, 1,373 (35.3%) were obese; 2,895 (74.6%) were ccRCC and 985 (25.3%) were non-ccRCC (chRCC 246 [24.9%], pRCC 469 [47.6%] and vhRCC 270 [27.4%]). MVA in ccRCC revealed obesity associated with decreased risk of ACM, CSM and recurrence (hazard ratio [HR] 0.80, P = 0.044; HR 0.71, P = 0.039; HR 0.73, P = 0.012, respectively), while in non-ccRCC was not associated with decreased risk of ACM, CSM, and recurrence (P = 0.84, P = 0.53, P = 0.84, respectively). Subset analysis in stage IV ccRCC demonstrated obesity as associated with a decreased risk of ACM, CSM, and recurrence (HR 0.68, P = 0.04; HR 0.59, P = 0.01; HR 0.59, P = 0.01, respectively), while in stage I-III ccRCC was not (P = 0.21; P = 0.30; P = 0.19, respectively).
Our findings refute a broad "obesity paradox" for RCC. Obesity was not associated with improved survival in non-ccRCC and in nonmetastatic ccRCC, while metastatic ccRCC patients with obesity had improved survival outcomes.
Urologic oncology. 2024 Feb 09 [Epub ahead of print]
Cesare Saitta, Jonathan A Afari, Arman Walia, Dattatraya Patil, Hajime Tanaka, Kevin Hakimi, Luke Wang, Margaret F Meagher, Franklin Liu, Mimi V Nguyen, Dhruv Puri, Clara Cerrato, Ava Saidian, Masaki Kobayashi, Shohei Fukuda, Yasuhisa Fujii, Viraj Master, Ithaar H Derweesh
Department of Urology, UC San Diego Health System, San Diego, CA., Department of Urology, Emory Medical Center, Atlanta, GA., Department of Urology, Tokyo Medical and Dental University, Tokyo, Japan., Department of Urology, UC San Diego Health System, San Diego, CA. Electronic address: .