Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston.
Head and Neck Section, Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston3Radiation Oncology Unit, Chulabhorn Hospital, Bangkok, Thailand.
JAMA Oncol. 2016 Jun 1;2(6):782-9. doi: 10.1001/jamaoncol.2015.6339.
Major weight loss is common in patients with head and neck squamous cell carcinoma (HNSCC) who undergo radiotherapy (RT). How baseline and posttreatment body composition affects outcome is unknown.
To determine whether lean body mass before and after RT for HNSCC predicts survival and locoregional control.
DESIGN, SETTING, AND PARTICIPANT: Retrospective study of 2840 patients with pathologically proven HNSCC undergoing curative RT at a single academic cancer referral center from October 1, 2003, to August 31, 2013. One hundred ninety patients had computed tomographic (CT) scans available for analysis of skeletal muscle (SM). The effect of pre-RT and post-RT SM depletion (defined as a CT-measured L3 SM index of less than 52.4 cm2/m2 for men and less than 38.5 cm2/m2 for women) on survival and disease control was evaluated. Final follow-up was completed on September 27, 2014, and data were analyzed from October 1, 2014, to November 29, 2015.
Primary outcomes were overall and disease-specific survival and locoregional control. Secondary analyses included the influence of pre-RT body mass index (BMI) and interscan weight loss on survival and recurrence.
Among the 2840 consecutive patients who underwent screening, 190 had whole-body positron emission tomography-CT or abdominal CT scans before and after RT and were included for analysis. Of these, 160 (84.2%) were men and 30 (15.8%) were women; their mean (SD) age was 57.7 (9.4) years. Median follow up was 68.6 months. Skeletal muscle depletion was detected in 67 patients (35.3%) before RT and an additional 58 patients (30.5%) after RT. Decreased overall survival was predicted by SM depletion before RT (hazard ratio [HR], 1.92; 95% CI, 1.19-3.11; P = .007) and after RT (HR, 2.03; 95% CI, 1.02-4.24; P = .04). Increased BMI was associated with significantly improved survival (HR per 1-U increase in BMI, 0.91; 95% CI, 0.87-0.96; P < .001). Weight loss without SM depletion did not affect outcomes. Post-RT SM depletion was more substantive in competing multivariate models of mortality risk than weight loss-based metrics (Bayesian information criteria difference, 7.9), but pre-RT BMI demonstrated the greatest prognostic value.
Diminished SM mass assessed by CT imaging or BMI can predict oncologic outcomes for patients with HNSCC, whereas weight loss after RT initiation does not predict SM loss or survival.
重要性：在接受放疗（RT）的头颈部鳞状细胞癌（HNSCC）患者中，体重明显减轻很常见。目前尚不清楚基线和治疗后身体成分如何影响预后。
目的：确定 HNSCC 患者在 RT 前后的瘦体重是否可预测生存和局部区域控制。
设计、环境和参与者：对 2003 年 10 月 1 日至 2013 年 8 月 31 日期间在一家学术癌症转诊中心接受根治性 RT 的 2840 例经病理证实的 HNSCC 患者进行回顾性研究。190 例患者有 CT 扫描可用于分析骨骼肌（SM）。评估了 RT 前和 RT 后 SM 消耗（定义为 CT 测量的 L3 SM 指数男性<52.4 cm2/m2，女性<38.5 cm2/m2）对生存和疾病控制的影响。最终随访于 2014 年 9 月 27 日完成，数据分析于 2014 年 10 月 1 日至 2015 年 11 月 29 日进行。
主要结局和测量指标：主要结局为总体和疾病特异性生存及局部区域控制。次要分析包括 RT 前 BMI 和扫描间体重减轻对生存和复发的影响。
结果：在接受筛选的 2840 例连续患者中，有 190 例在 RT 前后进行了全身正电子发射断层扫描-CT 或腹部 CT 扫描，包括在分析中。其中，160 例（84.2%）为男性，30 例（15.8%）为女性；平均（SD）年龄为 57.7（9.4）岁。中位随访时间为 68.6 个月。在 RT 前，67 例（35.3%）患者检测到骨骼肌消耗，在 RT 后，另外 58 例（30.5%）患者检测到骨骼肌消耗。RT 前的 SM 消耗与较低的总体生存率相关（HR，1.92；95%CI，1.19-3.11；P=0.007）和 RT 后（HR，2.03；95%CI，1.02-4.24；P=0.04）。BMI 的增加与生存率的显著提高相关（每增加 1 个 BMI 的 HR，0.91；95%CI，0.87-0.96；P<0.001）。无 SM 消耗的体重减轻不会影响结局。与基于体重减轻的指标相比，RT 后 SM 消耗在死亡率风险的多变量竞争模型中更为显著（贝叶斯信息准则差异，7.9），但 RT 前 BMI 显示出最大的预后价值。
结论和相关性：通过 CT 成像或 BMI 评估的 SM 质量减少可预测 HNSCC 患者的肿瘤学结局，而 RT 开始后的体重减轻并不能预测 SM 丢失或生存。
