Watanabe Daisuke, Horiguchi Akio, Tasaki Shinsuke, Kuroda Kenji, Sato Akinori, Asakuma Junichi, Ito Keiichi, Asano Tomohiko
Department of Urology, National Defense Medical College, Tokorozawa 359-8513, Japan.
Mol Clin Oncol. 2018 Jan;8(1):47-53. doi: 10.3892/mco.2017.1473. Epub 2017 Oct 27.
Although obesity defined by a high body mass index (BMI) is generally associated with increased risk of renal cell carcinoma (RCC), low BMI has paradoxically been associated with increased tumor aggressiveness and poor prognosis. As anorexia-cachexia syndrome (ACS) is associated with decreased BMI and is frequently observed in patients with advanced RCC, the present study investigated the association of BMI with tumor aggressiveness and prognosis in RCC in relation to ACS. The association of BMI with clinicopathological parameters was analyzed in 503 consecutive patients who underwent surgery for RCC. Kaplan-Meier curves and rates of overall survival (OS) stratified by BMI were also compared in relation to the presence or absence of ACS, defined as the presence of anorexia or malaise, and/or weight loss and/or hypoalbuminemia. Low BMI was significantly associated with high-grade tumors (P=0.0027) and the presence of distant metastasis (P=0.0025), and patients with a lower BMI had significantly shorter OS than those with a higher BMI (P=0.0441). Patients with ACS had a significantly lower BMI (mean, 21.5 kg/m) than those without ACS (mean, 23.5 kg/m; P<0.0001) and had significantly shorter OS than those without ACS (P<0.0001). On multivariate analysis, ACS was an independent predictor of short OS [P=0.0089; hazard ratio (HR), 2.21; 95% confidence interval (CI), 1.22-3.92] and short cancer-specific survival (P=0.0308; HR, 2.03; 95% CI, 1.07-3.78); however, BMI was not (P=0.5440 and P=0.6804, respectively). In the 413 patients without ACS at initial presentation, BMI was not associated with any clinicopathological parameters or OS (log-rank, P=0.4591). BMI itself was not a predictor of survival in patients without ACS, and the association between low BMI and increased tumor aggressiveness and poor prognosis could be due to ACS.
尽管由高体重指数（BMI）定义的肥胖通常与肾细胞癌（RCC）风险增加相关，但矛盾的是，低BMI却与肿瘤侵袭性增加和预后不良有关。由于厌食-恶病质综合征（ACS）与BMI降低相关，且在晚期RCC患者中经常观察到，本研究调查了BMI与RCC中肿瘤侵袭性及预后的关系，并与ACS相关联。对503例连续接受RCC手术的患者分析了BMI与临床病理参数之间的关联。还比较了根据BMI分层的Kaplan-Meier曲线和总生存率（OS），并考虑了是否存在ACS，ACS定义为存在厌食或不适，和/或体重减轻和/或低白蛋白血症。低BMI与高级别肿瘤（P = 0.0027）和远处转移的存在（P = 0.0025）显著相关，BMI较低的患者的OS明显短于BMI较高的患者（P = 0.0441）。有ACS的患者的BMI显著低于无ACS的患者（平均21.5kg/m²）（平均23.5kg/m²；P < 0.0001），且OS明显短于无ACS的患者（P < 0.0001）。多因素分析显示，ACS是OS缩短[P = 0.0089；风险比（HR），2.21；95%置信区间（CI），1.22 - 3.92]和癌症特异性生存缩短（P = 0.0308；HR，2.03；95%CI，1.07 - 3.78）的独立预测因素；然而，BMI并非如此（分别为P = 0.5440和P = 0.6804）。在初次就诊时无ACS的413例患者中，BMI与任何临床病理参数或OS均无关联（对数秩检验，P = 0.4591）。BMI本身并非无ACS患者生存的预测因素，低BMI与肿瘤侵袭性增加和预后不良之间的关联可能归因于ACS。
