专家视点：老年癌症患者营养不良筛查

英国曼彻斯特——在国际老年肿瘤学会(ISOG)年会营养问题专题会上，ISOG营养工作组主席、米兰大学外科肿瘤专家Federico Bozzetti博士指出，应开展老年癌症患者营养不良筛查，并采取个体化、多模式干预措施以满足患者营养需求。

Bozzetti博士认为，营养对于老年癌症患者非常重要，但仍有许多肿瘤医生忽视了这一点。他承认目前的问题是缺乏能够证实癌症患者(尤其是老年患者)营养支持效果的随机临床试验。但已有证据显示，营养不良与普通患者临床结局不良、住院时间延长、恢复期延长、生活质量下降、发病率提高以及死亡率增加有关(Clin. Nutr. 2008;27:340-9; Eur. J. Clin. Nutr. 2007;62:687-94; Br. J. Nutr. 2004; 92:105-11; Am. J. Clin.Nutr. 1997;66:1232)。他强调，无论健康与否，老年人均需要营养。

SIOG营养工作组按照其最初目标，制定了一份营养支持临床指南共识报告，预计在明年早些时候出版发行。

Bozzetti博士认为，目前营养支持介于医学和支持治疗之间，严重营养不良患者从中受益更为多见。

如何筛查营养不良？

瑞士伯尼尔大学医院的Zeno Stanga博士引用欧洲临床营养和代谢学会的定义说道：“营养不良是一种亚急性或慢性营养状态，是一种由于不同程度的营养过剩或不良与炎性活动联合导致的身体成分改变和功能下降的状态。”

Stanga博士指出，高达56%的老年患者营养不良(Clin. Nutr. 2006;25:563-72)，20~80%的癌症患者处于严重营养风险之中。他建议，应该对所有癌症患者进行营养筛查， 以便制定恰当的营养治疗计划，实施个体化干预措施，并时常调整以满足个体需求。

Stanga博士认为，多种因素影响营养状态，而食物摄入、体重指数、病理性体重下降和疾病严重程度是4项需要评估的关键因素，仅测定单一指标是不够的。现有多种筛查工具可用于确认患者营养不良风险以及是否需要营养支持。至于那种筛查工具最佳目前尚无共识，营养不良通用筛查工具(MUST)、营养风险筛查(NRS)2002版以及简易营养评价精法(MNA-SF)均可供选择应用。

Stanga博士强调，重要的是筛查方案应采用已经验证的工具，以便患者得到适当的干预措施。

需要哪种类型的营养支持？

SIOG营养工作组成员、葡萄牙里斯本大学的Paula Ravasco博士认为，辅助营养对于癌症患者的治疗非常重要，目前的证据支持整合早期和个体化营养咨询作为辅助治疗。


Paula Ravasco博士
 
Ravasco博士此前报告了该领域为数不多的一项随机对照试验结果(Am. J. Clin. Nutr. 2012 Nov. 7 [doi: 10.3945/ajcn.111.018838])。该研究表明，个体化营养咨询结合食用常规食物有益于结直肠癌放疗患者。与未接受咨询的患者相比，接受咨询的患者在营养摄入与状态改善、毒性降低、生活质量改善方面均有所受益。

Ravasco博士所在医院采用的循证饮食干预措施包括咨询和应用调整后的规定治疗饮食以满足患者特殊需求。她认为，或许应尽可能维持患者习惯的常规饮食模式。

就个体化营养支持，Bozzetti博士指出，胃肠道功能正常的患者能够响应咨询并食用口服膳食补充剂，这适合大部分患者。如果患者上消化道功能不全，鼻饲管或鼻胃管喂养可能是短期营养支持的最佳选择，而长期支持可能需要经皮胃造瘘术。对于无功能胃肠道患者，只能采取肠外营养，或以此作为口服营养不足的补充方法。

营养问题专题会得到雅培营养公司无限制教育基金部分支持。Bozzetti博士、 Ravasco博士和 Stanga博士没有就潜在利益冲突做任何披露。

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By: SARA FREEMAN, Oncology Practice

MANCHESTER, ENGLAND – Elderly cancer patients need to be screened for malnutrition, and individualized, multimodal interventions should be used in those found to require nourishment, according to the chair of a task force on nutrition in geriatric oncology.

"Nutrition is important in [elderly] cancer patients, yet still many oncologists neglect this aspect [of treatment]," the chair, Dr. Federico Bozzetti, told attendees during a special session on nutritional issues at the annual meeting of the International Society of Geriatric Oncology.

Standing in the way is a paucity of randomized clinical trials demonstrating the efficacy of nutritional support in cancer patients, and notably in those who are elderly, acknowledged Dr. Bozzetti, a surgical oncologist from the University of Milan.

Evidence links malnutrition to worse clinical outcomes, increased hospital stays, a longer duration of convalescence, reduced quality of life, increased morbidity, and increased mortality in the general patient population, however (Clin. Nutr. 2008;27:340-9; Eur. J. Clin. Nutr. 2007;62:687-94; Br. J. Nutr. 2004; 92:105-11; Am. J. Clin.Nutr. 1997;66:1232), Dr. Bozzetti noted.

"Old people, regardless of whether they are healthy or ill, need to be nourished," he said.

The International Society of Geriatric Oncology (SIOG) Task Force on Nutrition has as its initial aim development of a consensus-based report to provide practical guidance on nutritional support. The report is due for publication early next year.

Nutritional support currently falls "somewhere between medicine and supportive care," Dr. Bozzetti suggested, adding that beneficial effects are more likely to be seen in patients who are severely malnourished than in those who are mildly malnourished.

How Can You Screen For Malnutrition?

"Malnutrition is a subacute or chronic state of nutrition," said Dr. Zeno Stanga of University Hospital Bern (Switzerland), citing the European Society for Clinical Nutrition and Metabolism definition. It is a state "in which a combination of varying degrees of over- or undernutrition and inflammatory activity have led to a change in body composition and diminished function," he added.

Data suggest that up to 56% of geriatric patients are malnourished (Clin. Nutr. 2006;25:563-72), he noted, with around 20%-80% of cancer patients at severe nutritional risk.

"All cancer patients must receive a nutritional screening at presentation," Dr. Stanga proposed. This should be performed in order to plan adequate nutritional therapy, with interventions tailored to the individual’s needs and revised often.

Nutritional status can be influenced by a variety of factors, with food intake, body mass index, pathologic weight loss, and the severity of disease being the four key ones to assess. Measuring a single parameter is not enough, he said, and there are several screening tools that may help to identify if a patient is at risk of malnutrition and requires nutritional support.

Although there is no consensus on which tool is best for nutritional screening, the options include the Malnutritional Universal Screening Tool (MUST), the Nutritional Risk Screening (NRS) 2002, and the Mini Nutritional Assessment Short Form (MNA-SF).

What is important, Dr. Stanga maintained, is that a screening protocol be implemented at institutions using a validated tool, and that patients be given appropriate action plans as a result.

What Type of Nutritional Support?

Adjuvant nutrition can play an important role in the management of cancer patients, said Dr. Paula Ravasco of the University of Lisbon.

"The evidence today argues for the integration of both early and individualized nutritional counseling as adjuvant therapy," said Dr. Ravasco, a member of the SIOG Task Force on Nutrition.

Dr. Ravasco has previously reported the findings of one of the few randomized controlled trials in this area (Am. J. Clin. Nutr. 2012 Nov. 7 [doi: 10.3945/ajcn.111.018838]), showing that individualized nutritional counseling with regular foods is of benefit in patients with colorectal cancer treated with radiotherapy. Patients who underwent nutritional counseling had improved nutritional intake and status, reduced toxicity, and improved quality of life compared with patients who received no counseling.

The evidence-based dietary intervention used at her institution involves counseling and using prescribed therapeutic diets that are modified to fulfill the specific requirement of patients. "We perhaps have to maintain, as far as possible, the usual dietary pattern that the patient usually has," Dr. Ravasco said.

On the topic of tailoring nutritional support, Dr. Bozzetti noted that patients with a functioning gastrointestinal (GI) tract might respond to counseling and the use of oral dietary supplements or stimulants. "These have the potential to be used in a very large number of patients," he said.

Nasogastric or nasojejunal tube feeding might be the best option for short-term nutritional support if the upper GI tract is not working, he suggested. Percutaneous gastrostomy may be needed for long-term support. Parenteral nutrition may be used on its own in those with a nonfunctioning GI tract, or as a practical way to supplement inadequate oral nutrition, Dr. Bozzetti said.

The session on nutritional issues in elderly cancer patients was partially supported by an unrestricted educational grant from Abbott Nutrition. Dr. Bozzetti, Dr. Ravasco, and Dr. Stanga did not make any disclosures about potential conflicts of interest.