Erlotinib, a tyrosine kinase inhibitor, has been shown to improve the survival of patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer. Sarcopenia is a status with increasing importance in lung cancer, and it may predict a poor prognosis. We aimed to evaluate the impact of sarcopenia on erlotinib therapy and prognosis in patients with EGFR-mutated (exon 19 or 21 L858R) metastatic lung adenocarcinoma. Sarcopenia was defined as skeletal muscle index ≤39 cm2/m2 for women and ≤55 cm2/m2 for men. The patient characteristics, inflammation parameters, clinical and survival outcomes of the erlotinib therapy were examined according to sarcopenia status. We also analyzed the erlotinib treatment-related toxicity. Seventy-two patients were included in our retrospective study, and the mean age of the patients was 63.7 years. A total of 39 (54.2%) patients were diagnosed with sarcopenia. Patients with sarcopenia had a poor prognosis and had a shorter median progression-free survival (PFS) than patients without sarcopenia (10.5 months vs. 21.8 months, p=0.002). Sarcopenia (HR 2.08) and C-reactive protein > 6.5 mg/L (HR 2.57) were determined as independent poor prognostic factors for PFS of erlotinib therapy. Treatment-related toxicity occurred in 34.7% of patients treated with erlotinib, and sarcopenia did not significantly affect treatment-related toxicity. We also found that sarcopenia significantly affected the response to erlotinib. The expected survival outcomes may be low when erlotinib therapy is used in patients with sarcopenia and metastatic lung adenocarcinoma. This study showed that survival and clinical outcomes could be better predicted by detecting sarcopenia in patients with lung cancer using erlotinib.

中文翻译：

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肌肉减少症对转移性肺腺癌患者厄洛替尼治疗的影响。

厄洛替尼是一种酪氨酸激酶抑制剂，已被证明可以改善表皮生长因子受体 (EGFR) 突变的非小细胞肺癌患者的生存期。肌肉减少症是一种在肺癌中越来越重要的状态，它可能预示着预后不良。我们旨在评估肌肉减少症对 EGFR 突变（外显子 19 或 21 L858R）转移性肺腺癌患者厄洛替尼治疗和预后的影响。肌肉减少症定义为女性骨骼肌指数≤39 cm2/m2，男性≤55 cm2/m2。根据肌肉减少症状态检查厄洛替尼治疗的患者特征、炎症参数、临床和生存结果。我们还分析了厄洛替尼治疗相关的毒性。我们的回顾性研究纳入了 72 名患者，患者的平均年龄为 63.7 岁。共有 39 名 (54.2%) 患者被诊断为肌肉减少症。与没有肌肉减少症的患者相比，肌肉减少症患者预后较差，中位无进展生存期 (PFS) 更短（10.5 个月对 21.8 个月，p=0.002）。肌肉减少症 (HR 2.08) 和 C 反应蛋白 > 6.5 mg/L (HR 2.57) 被确定为厄洛替尼治疗 PFS 的独立不良预后因素。接受厄洛替尼治疗的患者中有 34.7% 发生治疗相关毒性，肌肉减少症对治疗相关毒性没有显着影响。我们还发现肌肉减少症显着影响对厄洛替尼的反应。当厄洛替尼治疗肌肉减少症和转移性肺腺癌患者时，预期的生存结果可能很低。