Psutka Sarah P, Boorjian Stephen A, Moynagh Michael R, Schmit Grant D, Frank Igor, Carrasco Alonso, Stewart Suzanne B, Tarrell Robert, Thapa Prabin, Tollefson Matthew K
Department of Urology, Mayo Clinic, Rochester, Minnesota.
Department of Radiology, Mayo Clinic, Rochester, Minnesota.
J Urol. 2015 May;193(5):1507-13. doi: 10.1016/j.juro.2014.11.088. Epub 2014 Nov 22.
We assess the impact of obesity, as measured conventionally by body mass index vs excess adiposity as measured by fat mass index, on mortality after radical cystectomy for bladder cancer, adjusting for the presence of skeletal muscle wasting.
This retrospective cohort study included 262 patients treated with radical cystectomy for bladder cancer between 2000 and 2008 at the Mayo Clinic. Lumbar skeletal muscle and adipose compartment areas were measured on preoperative imaging. Overall survival was compared according to gender specific consensus fat mass index and skeletal muscle index thresholds as well as conventional body mass index based criteria. Predictors of all cause mortality were assessed by multivariable modeling.
Increasing body mass index correlated with improved overall survival (p=0.03) while fat mass index based obesity did not (p=0.08). After stratification by sarcopenia, no obesity related 5-year overall survival benefit was observed (68% vs 51.4%, p=0.2 obese vs normal and 40% vs 37.4%, p=0.7 sarcopenia vs sarcopenic/obese). On multivariable analysis class I obesity according to body mass index (HR 0.79, p=0.33) or fat mass index criteria (HR 0.85, p=0.45) was not independently associated with all cause mortality after adjusting for sarcopenia (HR 1.7, p=0.01) as well as age, performance status, pTN stage and smoking status. However, in patients with normal lean muscle mass each 1 kg/m(2) increase in weight or adipose mass was associated with a 7% to 14% decrease in all cause mortality.
After adjusting for lean muscle wasting, neither measurements of obesity nor adiposity were significantly associated with all cause mortality in patients treated with radical cystectomy, although subanalyses suggest a potential benefit among those with normal lean muscle mass.
我们评估通过传统的体重指数衡量的肥胖以及通过脂肪量指数衡量的过多肥胖对膀胱癌根治性膀胱切除术后死亡率的影响，并对骨骼肌消瘦的存在进行校正。
这项回顾性队列研究纳入了2000年至2008年间在梅奥诊所接受膀胱癌根治性膀胱切除术的262例患者。术前影像学测量腰椎骨骼肌和脂肪组织区域。根据性别特异性的共识脂肪量指数和骨骼肌指数阈值以及基于传统体重指数的标准比较总生存期。通过多变量建模评估全因死亡率的预测因素。
体重指数增加与总生存期改善相关（p = 0.03），而基于脂肪量指数的肥胖则不然（p = 0.08）。在按肌少症分层后，未观察到与肥胖相关的5年总生存期获益（肥胖组与正常组相比为68%对51.4%，p = 0.2；肌少症组与肌少症/肥胖组相比为40%对37.4%，p = 0.7）。多变量分析显示，根据体重指数（HR 0.79，p = 0.33）或脂肪量指数标准（HR 0.85，p = 0.45）的I级肥胖在校正肌少症（HR 1.7，p = 0.01）以及年龄、体能状态、pTN分期和吸烟状态后，与全因死亡率无独立相关性。然而，在瘦肌肉量正常的患者中，体重或脂肪量每增加1 kg/m²，全因死亡率降低7%至14%。
在校正瘦肌肉消瘦后，对于接受根治性膀胱切除术的患者，肥胖或脂肪量的测量与全因死亡率均无显著相关性，尽管亚组分析提示在瘦肌肉量正常的患者中可能存在获益。
