Yasukiyo Murakami1,2, Kazumasa Matsumoto1, Masaomi Ikeda3, Takuji Utsunomiya2, Takahiro Hirayama1, Dai Koguchi4, Daisuke Matsuda5, Norihiko Okuno6, Yoshinori Taoka4, Akira Irie2, Masatsugu Iwamura1. 1. Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan. 2. Department of Urology, Kanagawa Prefectural Federation of Agricultural Cooperatives for Health and Welfare Sagamihara Kyodo Hospital, Kanagawa, Japan. 3. Department of Urology, Kitasato University Kitasato Institute Hospital, Tokyo, Japan. 4. Department of Urology, Kitasato University Medical Center, Saitama, Japan. 5. Department of Urology, Higashiyamato Hospital, Tokyo, Japan. 6. Department of Urology, National Hospital Organization Sagamihara Hospital, Kanagawa, Japan.
Abstract
AIM: To evaluate the impact of body mass index (BMI) on the oncological outcomes of urothelial carcinoma (UC) patients. PATIENTS AND METHODS: We retrospectively analyzed data from 818 patients with upper tract urothelial cancer (UTUC) and bladder cancer (BC) who were treated with radical nephroureterectomy (RNU) or radical cystectomy (RC) between 1990 and 2015 at six different institutions in Japan. Patients with distant metastasis at diagnosis and those who received neoadjuvant therapies were excluded, leaving 727 eligible patients (UTUC: n = 441; BC: n = 286). Patients were classified into four groups according to World Health Organization BMI criteria: underweight (BMI <18.5 kg/m2 ), normal weight (BMI 18.5-25 kg/m2 ), overweight (BMI 25.1-30 kg/m2 ), and obese (BMI >30 kg/m2 ). RESULTS: Overweight UTUC and BC patients achieved significantly better cancer-specific survival (CSS) than the other three groups. However, obese UTUC and BC patients had significantly worse CSS than the other three groups (UTUC: P = 0.031; BC: P = 0.0019). Multivariate analysis of BC patients demonstrated that obesity was an independent predictor of unfavorable CSS (hazard ratio [HR] = 7.47; P = 0.002) and that being underweight was an independent predictor of favorable CSS (HR = 0.37; P = 0.029). However, BMI was not a prognostic factor for CSS in UTUC patients according to multivariate analysis. CONCLUSIONS: Obesity was an independent predictor of BC patients requiring RC. Conversely, being underweight was associated with a favorable prognosis for BC patients. However, BMI was not an independent prognostic factor in patients with upper urinary tract cancer.
AIM: To evaluate the impact of body mass index (BMI) on the oncological outcomes of urothelial carcinoma (UC) patients. PATIENTS AND METHODS: We retrospectively analyzed data from 818 patients with upper tract urothelial cancer (UTUC) and bladder cancer (BC) who were treated with radical nephroureterectomy (RNU) or radical cystectomy (RC) between 1990 and 2015 at six different institutions in Japan. Patients with distant metastasis at diagnosis and those who received neoadjuvant therapies were excluded, leaving 727 eligible patients (UTUC: n = 441; BC: n = 286). Patients were classified into four groups according to World Health Organization BMI criteria: underweight (BMI <18.5 kg/m2 ), normal weight (BMI 18.5-25 kg/m2 ), overweight (BMI 25.1-30 kg/m2 ), and obese (BMI >30 kg/m2 ). RESULTS: Overweight UTUC and BC patients achieved significantly better cancer-specific survival (CSS) than the other three groups. However, obese UTUC and BC patients had significantly worse CSS than the other three groups (UTUC: P = 0.031; BC: P = 0.0019). Multivariate analysis of BC patients demonstrated that obesity was an independent predictor of unfavorable CSS (hazard ratio [HR] = 7.47; P = 0.002) and that being underweight was an independent predictor of favorable CSS (HR = 0.37; P = 0.029). However, BMI was not a prognostic factor for CSS in UTUC patients according to multivariate analysis. CONCLUSIONS:Obesity was an independent predictor of BC patients requiring RC. Conversely, being underweight was associated with a favorable prognosis for BC patients. However, BMI was not an independent prognostic factor in patients with upper urinary tract cancer.