Sarcopenia as a Predictor of Survival in Bladder Cancer Patients Receiving Radiotherapy - Expert Commentary

There is not enough data on the prognostic value of sarcopenia and nutritional indices in bladder cancer patients who receive definitive radiotherapy. A recent paper by Stangl-Kremser et al. in Urologic Oncology studied the role of sarcopenia and nutritional indices in the overall survival for patients with high-risk urothelial carcinoma who are unfit to for chemotherapy or radical cystectomy. 

The investigators included 68 who only received radiation therapy. The median age was 82 years (interquartile range [IQR] 75−86) with a comorbidity index of 7.5 (IQR 6−10). The investigators defined sarcopenia as skeletal muscle index (SMI) <39 cm²/m² in women and <55 cm²/m² in men before treatment. The authors also used a body mass index-adjusted definition of sarcopenia to evaluate for sarcopenic obesity. The investigators assessed the association between sarcopenia, body composition, and nutritional status with the overall survival and cancer-specific survival using univariate Cox proportional hazards regression analyses. 

The investigators found that 49 patients (72%) were sarcopenic. There was no significant association between sarcopenia and overall survival (hazard ratio [HR]1.31, 95% confidence interval [CI] 0.6−2.6, P = 0.44) or cancer-specific survival (HR 0.6, 95% CI 0.1−2.2, P = 0.45).  However, BMI-adjusted sarcopenia was significantly associated with cancer-specific survival (HR 5.0, 95% CI 1.4−16.7, P = 0.01). 

This study sheds light on the role of nutritional and body-composition indices as prognostic and predictive factors in bladder cancer patients. Additional research is needed to understand the biological determinants of sarcopenia and its pathophysiology in bladder cancer are required. 

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

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1. Stangl-Kremser J, D'Andrea D, Vartolomei M, Abufaraj M, Goldner G, Baltzer P, Shariat SF, Tamandl D. Prognostic value of nutritional indices and body composition parameters including sarcopenia in patients treated with radiotherapy for urothelial carcinoma of the bladder. Urol Oncol. 2018 Dec 18. pii: S1078-1439(18)30447-2. doi: 10.1016/j.urolonc.2018.11.001.