恶液质是一种骨骼肌量进行性下降的代谢综合征，伴随或不伴随脂肪量减少，在晚期肿瘤患者中普遍存在。恶 液质降低抗肿瘤治疗疗效，增加肿瘤放化疗不良反应，增加肿瘤患者死亡率，是预后不良的重要因素之一。恶液质促进肿 瘤的侵袭和转移，其机制尚不明确，可能与恶液质患者中存在的炎性反应、乏氧状态、瘦素水平下降、促血管生成因子释 放等有关。肿瘤恶液质的病理生理机制错综复杂，普遍认为肿瘤转移的患者，肿瘤负荷增加，患者发生恶液质的风险增加， 且其治疗效果欠佳，目前仍缺乏标准的治疗方案。进一步明确恶液质的病理生理特点及其促进肿瘤转移的机制，有助于指 导早期营养筛查和营养评估，明确恶液质的诊断，并对恶液质进行分期和分级管理，有效地预防和治疗恶液质，进而减少 肿瘤转移，改善患者生活质量及预后。本文通过探讨恶液质的病理生理特点及其促进肿瘤转移的相关分子机制，综述恶液 质与肿瘤转移的相关分子机制，为恶液质及肿瘤转移的治疗提供重要依据。

 Cachexia is a complex metabolic syndrome characterized by loss of skeletal muscle (with or without loss of fat mass), which affects the majority of late stage cancer patients. Cancer cachexia often seriously affects the treatment efficacy and increases the toxicity by chemotherapy and radiotherapy, further increasing mortality and leading to poor prognosis for cancer patients. The mechanism of cancer cachexia on metastasis have not been understood completely, which may be associated with inflammation, hypoxia, decreased expression of leptin and the release of proangiogenic factors in cancer patients with cachexia. The pathological and physiological characteristics of cachexia are complicated, and cancer cachexia is associated with poor response of therapy without standard treatment. There remains an urgency to study the pathophysiology of cachexia and the impact on metastasis to guide early nutrition screening and assessment, to identify the diagnosis of cachexia and to evaluate the stage and grade of cachexia. Also,   it is useful to predict and treat cachexia positively and effectively, to decrease the metastatic rate of tumor and improving quality of life. This review will summarize the effect of cancer cachexia on metastasis by exploring the pathophysiology of cachexia and the pathogeneses of cachexia on metastasis, to provide important basis on the treatment of cancer cachexia and metastasis.