Background

Body mass index (BMI) and sarcopenia status are well-established prognostic factors in patients with lung cancer. However, the relationship between the amount of adipose tissue and survival remains unclear.

Purpose

To investigate the association between baseline adipopenia and outcomes in patients with early-stage non–small cell lung cancer (NSCLC).

Materials and Methods

Consecutive patients who underwent surgical resection for stage I NSCLC between 2011 and 2015 at a single tertiary care center were retrospectively identified. The primary outcome was the 5-year overall survival (OS) rate, and secondary outcomes were the 5-year disease-free survival (DFS) rate and the major postoperative complication rate. The abdominal total fat volume at the waist and the skeletal muscle area at the L3 level were obtained from preoperative PET/CT data and were normalized by the height squared to calculate the fat volume index (FVI) and skeletal muscle index. Adipopenia was defined as the sex-specific lowest quartile of the FVI for the study sample, and sarcopenia was determined using the skeletal muscle index reference value (men, <55 cm²/m²; women, <39 cm²/m²). The association between body composition and outcomes was evaluated using Cox regression analysis.

Results

A total of 440 patients (median age, 65 years [interquartile range, 58–72 years]; 243 men) were evaluated. Most underweight patients (<20 kg/m²) had adipopenia (97%, 36 of 37 patients), but overweight patients (25–30 kg/m², n = 138) and obese patients (>30 kg/m², n = 14) did not have adipopenia (3%, four of 152 patients). In the group with a normal BMI (20–25 kg/m²), 28% (70 of 251 patients) had adipopenia and 67% (168 of 251 patients) had sarcopenia. After adjusting for age, sex, smoking history, surgical procedure, stage, histologic type, BMI, and sarcopenia, adipopenia was associated with reduced 5-year OS (hazard ratio [HR] = 2.2; 95% CI: 1.1, 3.8; P = .02) and 5-year non–cancer-specific OS rates (HR = 3.2; 95% CI: 1.2, 8.7; P = .02). There was no association between adipopenia and postoperative complications (P = .45) or between adipopenia and the 5-year DFS rate (P = .18).

Conclusion

Baseline adipopenia was associated with a reduced 5-year overall survival rate in patients with early-stage non–small cell lung cancer and may indicate risk for non–cancer-related death.

© RSNA, 2021

Online supplemental material is available for this article.

中文翻译：

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术前PET/CT脂肪减少与I期非小细胞肺癌死亡率的相关性

背景

体重指数 (BMI) 和肌肉减少症状态是肺癌患者公认的预后因素。然而，脂肪组织量与存活率之间的关系仍不清楚。

目的

研究基线脂肪减少与早期非小细胞肺癌 (NSCLC) 患者预后之间的关联。

材料和方法

回顾性地确定了 2011 年至 2015 年在单一三级医疗中心接受手术切除 I 期 NSCLC 的连续患者。主要结果是 5 年总生存 (OS) 率，次要结果是 5 年无病生存 (DFS) 率和主要术后并发症发生率。从术前PET/CT数据获得腰部腹部总脂肪体积和L3水平骨骼肌面积，并通过身高平方归一化计算脂肪体积指数（FVI）和骨骼肌指数。脂肪减少被定义为研究样本 FVI 的性别特异性最低四分位数，肌肉减少使用骨骼肌指数参考值（男性，<55 cm ² /m ²；女性，<39 cm² /米² )。使用 Cox 回归分析评估身体成分和结果之间的关联。

结果

总共评估了 440 名患者（中位年龄，65 岁 [四分位距，58-72 岁]；243 名男性）。大多数体重不足的患者 (<20 kg/m ² ) 有脂肪减少症 (97%，37 名患者中的 36 名)，但超重患者 (25–30 kg/m ²，n = 138) 和肥胖患者 (>30 kg/m ²，n = 14) 没有脂肪减少症（3%，152 名患者中的 4 名）。在体重指数正常（20-25 kg/m ²）的组中，28%（251 名患者中的 70 名）患有脂肪减少症，67%（251 名患者中的 168 名）患有肌肉减少症。在调整年龄、性别、吸烟史、手术程序、分期、组织学类型、BMI 和肌肉减少症后，脂肪减少症与 5 年 OS 降低相关（风险比 [HR] = 2.2；95% CI：1.1, 3.8；P= .02) 和 5 年非癌症特异性 OS 率（HR = 3.2；95% CI：1.2, 8.7；P = .02）。脂肪减少与术后并发症 ( P = .45) 或脂肪减少与 5 年 DFS 率 ( P = .18)之间没有关联。

结论

基线脂肪减少与早期非小细胞肺癌患者的 5 年总生存率降低有关，并可能表明非癌症相关死亡的风险。

©北美放射学会，2021

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