Background/Objectives: Sarcopenia is an emergent prognostic biomarker in clinical oncology. Albeit increasingly defined through skeletal muscle index (SMI) thresholding, the literature cut-offs fail to discern heterogeneous baseline muscularity across populations. This study assesses the prognostic impact of using cohort-specific SMI thresholds in a Portuguese metastatic non-small-cell lung cancer (mNSCLC) cohort.Methods: Retrospective study including mNSCLC patients treated between January 2017 and December 2022. ImageJ v1.54 g was used to assess cross-sectional CT imaging at the third lumbar vertebra (L3) and calculate L3SMI. Sarcopenia was defined both according to Prado et al. and L3SMI thresholds derived from receiver operating characteristic analysis. Overall survival (OS) was the primary endpoint. Secondary endpoints included first-line (1L) progression-free survival (PFS) and sarcopenia subgroup analysis regarding body mass index impact on OS.Results: The initial cohort included 197 patients. Mean age was 65 years (±11.31). Most tumors were adenocarcinomas (n= 165) and presented with metastasis (n= 154). SMI was evaluable in 184 patients: cohort-specific thresholds (<49.96 cm2/m2for men; <34.02 cm2/m2for women) yielded 46.74% sarcopenic patients (n= 86) versus 66.30% (n= 122) per the literature definition. Cohort-specific thresholds predicted both OS (12.75 versus 21.13 months, hazard ratio [HR] 1.654,p= 0.002) and PFS (7.92 versus 9.56 months, HR 1.503,p= 0.01). Among sarcopenic patients, overweight (HR 0.417,p= 0.01) and obesity (HR 2.723,p= 0.039) had contrasting impacts on OS.Conclusions: Amid reclassification of nearly one-fifth of the cohort, cohort-specific thresholds improved sarcopenia prognostication in mNSCLC. Homogeneity regarding both cancer treatment setting and ethnicity could be key to defining sarcopenia based on SMI.
背景/目的：肌肉减少症是临床肿瘤学中一个新兴的预后生物标志物。尽管目前越来越多地通过骨骼肌指数阈值进行定义，但现有文献中的截断值未能识别不同人群间异质性的基线肌肉状态。本研究旨在评估在葡萄牙转移性非小细胞肺癌队列中使用队列特异性SMI阈值的预后影响。 方法：本研究为回顾性研究，纳入2017年1月至2022年12月期间接受治疗的mNSCLC患者。使用ImageJ v1.54 g软件评估第三腰椎水平的横断面CT影像并计算L3SMI。肌肉减少症的定义同时依据Prado等人的标准以及通过受试者工作特征分析得出的L3SMI阈值。总生存期为主要终点。次要终点包括一线治疗无进展生存期，以及关于体重指数对总生存期影响的肌肉减少症亚组分析。 结果：初始队列包括197名患者。平均年龄为65岁（±11.31）。大多数肿瘤为腺癌（n=165）且伴有转移（n=154）。184名患者的SMI可评估：队列特异性阈值（男性<49.96 cm²/m²；女性<34.02 cm²/m²）判定46.74%的患者（n=86）为肌肉减少症，而根据文献定义该比例为66.30%（n=122）。队列特异性阈值对总生存期（12.75个月 vs 21.13个月，风险比1.654，p=0.002）和无进展生存期（7.92个月 vs 9.56个月，风险比1.503，p=0.01）均具有预测价值。在肌肉减少症患者中，超重（风险比0.417，p=0.01）和肥胖（风险比2.723，p=0.039）对总生存期的影响截然不同。 结论：在近五分之一的队列患者被重新分类的情况下，队列特异性阈值改善了mNSCLC中肌肉减少症的预后判断。癌症治疗环境和种族背景的同质性可能是基于SMI定义肌肉减少症的关键因素。
肿瘤(癌症)患者之家