Renal cell carcinoma (RCC) is a major urologic malignancy worldwide, with obesity recognized as a known risk factor. Interestingly, a higher body mass index (BMI) has been associated with improved outcomes in immunotherapy, a phenomenon termed the "obesity paradox. " This study investigates the influence of BMI on the effectiveness of immune combination therapies in Japanese patients with metastatic RCC.
A retrospective study was conducted on 243 Japanese patients with metastatic RCC who received immune combination therapies between 2018 and 2022. Patients were stratified into two groups: non-overweight/obesity (BMI < 25 kg/m2) and overweight/obesity (BMI ≥ 25 kg/m2). Survival outcomes, including progression-free survival (PFS) and overall survival (OS), were compared between the groups.
There was no significant difference in PFS between the groups. However, the overweight/obesity group showed a trend toward longer OS, particularly in patients receiving IO-IO regimens (P = 0.011). In contrast, although no statistically significant difference was observed in the IO-TKI regimen, there was a trend toward prolonged OS in the non-overweight/obesity group. No significant differences in immune-related adverse events were observed between the groups.
Higher BMI may be associated with better outcomes in immune combination therapy, especially with IO-IO regimens. These findings suggest that BMI could be a useful factor in optimizing RCC treatment. Further research with larger cohorts is needed to confirm these results and understand the mechanisms behind the "obesity paradox."
International journal of clinical oncology. 2025 Aug 20 [Epub ahead of print]
Toshiki Anami, Takanobu Motoshima, Yuto Matsushita, Takahiro Kojima, Shimpei Yamashita, Hisanori Taniguchi, Keisuke Monji, Ryo Ishiyama, Yoshihide Kawasaki, Takuma Kato, Shuichi Tatarano, Kimihiko Masui, Eijiro Nakamura, Tomoyuki Kaneko, Makito Miyake, Hiroshi Kitamura, Hideaki Miyake, Tomomi Kamba, Japan Urological Oncology Group
Department of Urology, Faculty of Life Sciences, Graduate School of Medical Sciences, Kumamoto University, Honjo 1-1-1, Chuouku, Kumamoto, 860-8556, Japan. ., Department of Urology, Faculty of Life Sciences, Graduate School of Medical Sciences, Kumamoto University, Honjo 1-1-1, Chuouku, Kumamoto, 860-8556, Japan., Department of Urology, Hamamatsu University School of Medicine, Shizuoka, Japan., Department of Urology, Aichi Cancer Center, Aichi, Japan., Department of Urology, Wakayama Medical University, Wakayama, Wakayama, Japan., Department of Urology and Andrology, Kansai Medical University, Osaka, Japan., Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan., Department of Urology, Tokyo Women's Medical University, Tokyo, Japan., Department of Urology, Tohoku University Graduate School of Medicine, Miyagi, Japan., Department of Urology, Faculty of Medicine, Kagawa University, Kagawa, Japan., Department of Urology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan., Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Urology, National Cancer Center Hospital, Tokyo, Japan., Department of Urology, Teikyo University School of Medicine, Tokyo, Japan., Department of Urology, Nara Medical University, Nara, Japan., Department of Urology, Faculty of Medicine, University of Toyama, Toyama, Japan., Department of Urology, Kobe University Graduate School of Medicine, Hyogo, Japan.