肌肉减少症是一种主要表现为骨骼肌含量减少和功能减退的临床综合征，常见于老年人及营养不良、慢性炎症、恶性肿瘤患者。肿瘤患者常伴有营养不良，肌肉减少症发生率较高，尤其是胃肠道肿瘤患者。本文旨在探讨胃肠道肿瘤患者中，肌肉减少症的发生率及其与治疗相关副反应和预后的关系，进而明确其在胃肠道肿瘤患者中的临床价值。以“肌肉减少症”和“肿瘤”为主要关键词检索CNKI及Pubmed相关文献，总结发现，首先，在胃肠道肿瘤患者中，肌肉减少症有较高的发生率，但诊断方法和标准不一，肌肉减少症的规范化诊断需包括肌肉含量评估和功能状态评估两方面；其次，肌肉减少症的发生对胃肠道肿瘤的治疗耐受性及预后产生不利影响，包括增加严重化疗毒副反应及手术并发症的发生率、延长手术后住院时间、增加远期死亡风险等。综上，肌肉减少症的评估在胃肠道肿瘤中体现重要的临床价值，有望成为预测胃肠道肿瘤患者临床结局的重要手段，同时，对肌肉减少症的临床干预也显得尤为重要。

Sarcopenia is a clinic syndrome mainly characterized by skeleton muscle mass and function loss, which is common in the elderly, malnutrition, chronic inflammation and cancer. Malnutrition and sarcopenia are common in cancer patients, especially in gastrointestinal tumors. This paper was to investigate the incidence of sarcopenia and the influences of sarcopenia on treatment-related side effects and prognosis, further to clarify its clinical significances in gastrointestinal cancer patients. Key words such as “sarcopenia” and “cancer” were reviewed in “CNKI” and “Pubmed” databases. The results suggested that, firstly, sarcopenia was prevalent in gastrointestinal cancer, however, diagnostic criteria for sarcopenia were variable, and the standard diagnostic criterion for sarcopenia should include muscle mass assessment and functional status assessment. Secondly, sarcopenia had negative impact on tolerance to treatment and prognosis, including higher risk of severe chemotherapeutic toxicity, more surgical complications, longer length of stay in hospital and shorter survival. In conclusion, the assessment of sarcopenia is essential in gastrointestinal cancer patients, and may become an important means to predict the clinical outcomes of gastrointestinal cancer. Otherwise, it also suggest that clinical intervention on sarcopenia is of great significance.