Definition of standardized assessment tools and interventions has been the backbone of protocol treatment in the context of the national cooperative oncology groups. In a similar manner, an algorithm of standardized nutritional assessment and intervention in the oncology patient has been developed and is increasingly being used as a guide to supportive nutrition in patients with cancer (Figure 1).
The proactive approach to nutritional care as defined by the algorithm is particularly important in patients with pancreatic cancer. These patients are at high risk for nutritional problems, based on the combined effects of the central anatomic location of the pancreas, endocrine and exocrine hormonal insufficiency, and treatment toxicity of multimodality therapy. When symptoms that affect nutrition (eg, anorexia or fat malabsorption) or significant weight loss are present at the time of diagnosis, the risk of progressive nutritional deterioration is further increased.
Because the onset of pancreatic cancer is insidious (delaying the presentation of the patient for diagnosis and treatment) and since weight loss is often progressive and may be rapid and severe, all factors that contribute to anorexia and other nutritional impact symptoms need to be assessed promptly and interventions initiated expeditiously. Extreme weight loss and malnutrition are important contributors to morbidity and mortality in patients with cancer and negatively impact response to antineoplastic therapy .
The goals of nutritional care are to support adequate caloric and nutrient intake, body composition, functional or performance status, immune function, and quality of life . A proactive nutritional approach in the care of oncology patients was outlined by Shils in 1979 in the principles of nutritional care in the cancer patient . Early detection of nutritional problems and prompt intervention are essential for success, whether the aim of treatment is cure or palliation. Once a patient's nutritional status has deteriorated to the point of severe depletion, attempts to reverse the condition rarely succeed, especially in the face of severe muscle wasting.
The primary cause of clinically evident nutritional deterioration in the patient with pancreatic cancer is inadequate intake and absorption of calories and protein. Examples of nutritional impact symptoms commonly noted in this patient population include early satiety, anorexia, fat malabsorption with crampy abdominal pain and bloating, nausea and/or vomiting, diarrhea or constipation, pain, and fatigue. These symptoms are treatable, but they require early detection and aggressive management. The pervasiveness of nutritional challenges in the patient with pancreatic cancer necessitates the use of standardized nutritional assessment tools and prompt intervention to optimize outcomes and quality of life for these patients.
Malnutrition has a wide range of adverse effects [1, 4-10]. The general impact of weight loss on outcomes has been known since the 1930's  and has been confirmed in a number of subsequent studies . Malnutrition is associated with adverse outcomes on a number of levels and contributes to higher health-care costs and prolonged hospitalizations [4, 12-14].Weight loss, nutritional deterioration, and inanition can hasten death, reduce response to treatment, exacerbate treatment toxicities and complications, and adversely affect quality of life in the oncology patient.
The incidence of malnutrition in general medical and surgical patients reported between 1973 and 1986 ranged from 30% to 50% . Malnutrition increases health care costs and prolongs hospital stays due to slower wound healing and increased incidence of complications [16-19]; it also increases mortality [11,13,14,20-22].
It has been estimated that 20% to 40% of patients with cancer die from the effects of malnutrition and its complications, as opposed to the malignancy per se . Significant weight loss is a major prognostic indicator in patients with cancer in terms of response to treatment and overall survival . Weight loss, malnutrition, or failure to thrive are the most commonly listed causes of death in cancer patients [7,8,24].
Criteria for grading of treatment-related toxicity are standardized and included in all oncology protocols. Criteria for weight loss are included in Table 1. The current grading of this nutritional toxicity, however, is inadequate [2,25,26]. Table 2 includes the standard definitions of severe and significant weight loss that are used in the nutrition literature. Significant weight loss is defined as that for which there is a statistically significant increase in morbidity and mortality. The weight loss toxicity criteria used in oncology protocols do not take into consideration 1) the time interval during which weight loss is experienced or 2) total cumulative weight loss, including pretreatment loss. In addition, the basis for the grading of life-threatening (grade 4) nutritional toxicity is not defined. Aspects of weight loss such as acuity and the extent of cumulative loss need to be incorporated into current treatment protocols to be consistent with known outcome data in the nutrition literature.
Quality of Life
Nutritional status affects quality of life in terms of self-image, the patient's ability to perform activities of daily living, and overall life satisfaction. The ability or desire to eat significantly affects a patient's ability to socialize and interact with family and friends [27,28]. Progressive weight loss causes distress to patients, their families, and the health care team.
With malnutrition and cachexia, muscle weakness and fatigue contribute to depression and may compound difficulties in meal preparation or participation in eating with family or friends . Reduced activity and bed rest lead to constipation and progressive muscle wasting. Progressive fatigue secondary to nutritional deterioration and inanition (severe muscle wasting) are the primary determinants affecting patients' ability to continue working at their jobs or to carry on any aspects of normal life.
Progressive nutritional deterioration in many patients with pancreatic cancer is caused by symptoms that affect food intake and nutrient absorption. Those symptoms that affect nutrition (anorexia, diarrhea, pain) can, in addition to contributing to weight loss, adversely affect quality of life. Weight loss often can be slowed or prevented by directing attention to those aspects which can be treated pharmacologically and/or behaviorally [2,23,29-31].
Few data are available on the economic impact of malnutrition in cancer patients. A significant contribution to health care costs is the average length of stay (ALOS) in a hospital. The average length of stay is nearly twice as long for malnourished patients as it is for patients with the same diagnosis who are well nourished . Little or no data have been available concerning the impact of nutritional status in the patient with cancer. Review of discharge data from the Fox Chase Cancer Center from 1993 to 1994 was carried out to evaluate the affect of nutritional status on ALOS. The average length of stay for all discharged patients was 5.8 days, whereas patients with a discharge diagnosis of dehydration and/or malnutrition had an ALOS of 9.4 days. With a discharge diagnosis of malnutrition alone, the ALOS was 13.4 days . The category of malnutrition/dehydration was important to consider, since patients in this category were not eating adequately during the 9.4 days and yet such patients often are not identified as being at risk of nutritional deficit.
Studies by Robinson et al  support the concept of proactive nutritional intervention. In these studies, the majority of increased health care dollars spent for care (approximately two- fold) involved patients with borderline malnutrition as compared with well-nourished patients. Only a relatively small additional cost was associated with managing severe malnutrition, as compared with borderline malnutrition.