营养饮食学会（美国营养师协会）成人肿瘤循证营养实践指南（九）
前情提要
基于共识出版物的推荐意见
不同时期癌症恶病质的营养评定
推荐意见
作为肺癌、胰腺癌或头颈部和胃肠道癌症患者或存在体重下降高风险或已有非意向性体重下降的患者营养评定的一部分，RDN应评定受营养影响的表现、炎性标志物（如C反应蛋白水平上升）和其他提示恶病质前期或癌症恶病质的消耗体征。
等级：共识，必不可少
依据：肺癌、胰腺癌或头颈部和胃肠道癌症患者或存在体重下降高风险或已有非意向性体重下降的患者需要进一步营养评定。这些患者出现恶病质的风险更高，因此更应及时识别并进行营养干预。
由RDN进行的营养评定和干预在恶病质前期和恶病质期提供更有效【129】。癌症恶病质分期见图7。
癌症代谢反应多种多样，因此，干预和处理行为相关因素以解决引起摄入减少的直接原因（如梗阻或吞咽困难）和继发原因（如抑郁、疲劳、疼痛或胃肠道功能下降）很重要。对晚期癌症患者进行症状管理可改善生存【130】。
营养不良的诊断
推荐意见
RDN应根据临床判断解释营养评定指标以诊断成人肿瘤患者的营养不良。出现2个或更多下列标准或特征支持成人肿瘤患者营养诊断为营养不良：能量摄入不足、非意向性体重下降、皮下脂肪丢失、肌肉含量减少、局部或广泛的液体潴留（可能掩盖体重下降）和握力下降。
等级：共识，必不可少
依据：尽管还无广泛接受的方法来诊断和记录成人营养不良，但工作组基于本学会/A.S.P.E.N.共识文件指导【119】（如图6所示）制定了成人肿瘤患者指南。RDN应根据临床判断解释营养评定指标以作出成人肿瘤患者营养不良的诊断。
营养干预
推荐意见
成人肿瘤患者已确定出现恶病质前期或癌症恶病质时，应由RDN开始快速积极干预以解决受营养影响的表现和维持瘦体重和体重或预防其下降。
等级：共识，有前提
依据：预防恶病质前期或癌症恶病质（见图7）患者体重下降，早干预比延迟干预更可能有效。癌症恶病质代谢紊乱促进消耗，可导致体重和瘦体重下降及产生不良结局。
营养监测和效果评估
推荐意见
为检查进展，RDN应在成人肿瘤患者每次随诊时监测和评估下列内容，并与个体理想的结局指标进行比较。它包括，但不限于人体测量、食物和营养摄入史、生化指标、医学检查、营养体格检查结果、个人史、患者/家族/客户疾病/健康史、社会史和精神心理/社会经济问题。
等级：共识，必不可少
对肺癌、胰腺癌或头颈部和胃肠道癌症患者或存在体重下降高风险或已有非意向性体重下降的患者，RDN应监测和评估受营养影响的表现、炎性标志物如（C反应蛋白水平上升）和其他提示恶病质前期或癌症恶病质的消耗体征。
等级：共识，必不可少
依据：应定期进行监测和效果评估以记录出现（或预计潜在）的营养状态改变，受营养影响的表现或对身体组成成分、功能、生活质量或临床结局产生的可观察到的不良影响，包括反映营养不良的6个指标，还有实验室结果和计划的肿瘤治疗。需要监测和评估这些指标以正确/有效地诊断营养相关问题，它们应是进一步营养干预的核心。不能达到最佳营养素摄入量可能会促使产生不良结局。
图6、成人肿瘤患者营养诊断为营养不良的标准【61,71,119,128】
出现2个或更多下列标准或特征支持成人肿瘤患者营养诊断为营养不良
能量摄入不足【119】
非意向性体重下降【119】
皮下脂肪丢失【71,119,129】
肌肉含量降低【61,119】
局部或广泛的液体潴留（可能掩盖体重下降）【119】
握力下降【119,128】
图7、恶病质定义。癌症恶病质分期为：恶病质前期、恶病质期、难治性恶病质期。改编自参考文献129和130。
癌症恶病质是一种多因素综合征，特点是骨骼肌含量进行性地下降（伴或不伴脂肪组织减少），不能完全被常规的营养支持所逆转，进而导致功能受损。其病理生理学特点是由食物摄入减少和代谢异常多种因素结合引起蛋白质和能量负平衡【129】。
恶病质前期（一般情况）由以下所有标准来确定：潜在的慢性疾病、在过去的6个月非意向性体重下降达平常体重的5%、慢性或复发性全身炎性反应、厌食或厌食相关症状【130】。
恶病质前期（对于癌症）以早期临床和代谢表现如食欲下降、糖耐量受损为特点，可出现在体重大幅非自主性下降（如达5%）之前。进展的风险可变，取决于癌症的类型、阶段、全身性炎性反应的存在、食物摄入少及对抗癌治疗缺乏反应【129】。
难治性恶病质可能是非常晚期的癌症（临终）或出现抗癌治疗无效的快速进展期癌症的结果。这一阶段与代谢活跃或存在使积极管理体重下降不再可能或不合适的因素有关。难治性恶病质的特点是行为状态评分低（如世界卫生组织评分为3或4）和预期寿命小于3个月【129】。
翻译：肖慧娟（天津市第三中心医院）
EAL RECOMMENDATIONS
Recommendations Based on Consensus Publications
Nutrition Assessment for the Stages of Cancer Cachexia
Recommendation
As part of a nutrition assessment in patients with lung, pancreatic, or head and neck and GI cancers or those who are at high risk for weight loss or have experienced UWL, RDNs should assess for nutrition impact symptoms, markers of inflammation (eg, elevated C-reactive protein value), and other signs of wasting that may indicate precachexia or cancer cachexia.
Rating: Consensus; Conditional
Rationale: Further nutrition assessment is needed for patients with lung, pancreatic, or head and neck and GI cancers or those who are at high risk for weight loss or have experienced UWL. Patients with these diagnoses are more at risk for cachexia and therefore have more to gain from timely identification and nutrition intervention.
Nutrition assessment and intervention by an RDN is most effective when provided in the stages of precachexia and cachexia.【129】The stages of cancer cachexia are shown in Figure 7.
The metabolic response to cancer is heterogeneous, so it is important to intervene and manipulate the factors that are behavior-related, to address the direct causes of decreased intake (eg, obstruction or dysphagia), and address the secondary causes (eg, depression, fatigue, pain, or GI function). Symptom management in patients with advanced cancer can improve survival.【130】
Nutrition Diagnosis of Malnutrition
Recommendation
RDNs should use clinical judgment in interpreting nutrition assessment data to diagnose malnutrition in adult oncology patients. The presence of two or more of the following criteria or characteristics supports a nutrition diagnosis of malnutrition in an adult oncology patient: insufficient energy intake, UWL, loss of subcutaneous fat, loss of muscle mass, localized or generalized fluid accumulation (that may mask weight loss), and reduced grip strength.
Rating: Consensus; Imperative
Rationale: Although there is no universally accepted approach to the diagnosis and documentation of adult malnutrition, the workgroup developed guidance for adult oncology patients, based on the Academy/A.S.P.E.N. consensus document guidance,【119】shown in Figure 6. RDNs should use clinical judgment in interpreting nutrition assessment data to make a nutrition diagnosis of malnutrition in adult oncology patients.
Nutrition Intervention
Recommendation
Cachexia In adult oncology patients who have been identified to have precachexia or cancer cachexia, prompt and aggressive intervention to address nutrition impact symptoms and preserve or prevent loss of LBM and weight should be initiated by an RDN.
Rating: Consensus; Conditional
Rationale: Early rather than later intervention to prevent weight loss in patients with precachexia or cancer cachexia (Figure 7) is more likely to be effective. The metabolic derangements in cancer cachexia that promote wasting can lead to loss of weight and LBM and poor outcomes.
Figure 7. Definitions of cachexia. There are several stages of cancer cachexia: precachexia, cachexia, and refractory cachexia. Adapted from references 129 and 130.
Cancer cachexia A multifactorial syndrome characterized by an ongoing loss of skeletal muscle mass (with or without loss of fat mass) that cannot be fully reversed by conventional nutritional support and leads to progressive functional impairment. The pathophysiology is characterized by a negative protein and energy balance, driven by a variable combination of reduced food intake and abnormal metabolism.【129】
Precachexia (in general) Defined by the presence of all of the following criteria: underlying chronic disease, unintended weight loss of up to 5% usual body weight during the past 6 months, chronic or recurrent systemic inflammatory response, and anorexia or anorexia-related symptoms.【130】
Precachexia (in cancer) Characterized by early clinical and metabolic signs such as loss of appetite and impaired glucose tolerance. Can precede substantial involuntary weight loss (ie, up to 5%). The risk of progression is variable and depends on cancer type, stage, presence of systemic inflammation, low food intake, and lack of response to anticancer therapy.【129】
Refractory cachexia May be a result of very advanced cancer (preterminal) or the presence of rapidly progressive cancer unresponsive to anticancer therapy. This stage is associated with active catabolism or the presence of factors that make active management of weight loss no longer possible or appropriate. Refractory cachexia is characterized by a low performance score (eg, World Health Organization grade 3 or 4) and a life expectancy <3 months.【129】