Preventing malnutrition in the cancer patient

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Abby S Bloch
PhD RD FADA
Nutrition Consultant
Associate Professor New York University Graduate School
Chair
National Advisory Committee on Nutrition and Physical Activity
American Cancer Society
E:[email protected]

Compromised nutritional status and diminished food intake is so common among cancer patients that health professionals may overlook the importance of determining the cause. Realistic, effective solutions to the problem may have a dramatic impact on the patient. More than one cause may be uncovered: emotional, physical, and metabolic factors may be combined or separate issues. If the clinician fails to sort out the cause or causes, an opportunity to resolve the problem may be lost.

A patient’s unexplained weight loss due to anorexia or loss of appetite should be pursued by the clinician. Anorexia can result from systemic responses still unexplained in the tumour process and may develop after the diagnosis is made. This can be secondary to the patient’s anxiety of confronting a life-threatening illness or to tumour activity. Anorexia (leading to cachexia) can be present early in the course of the disease limiting the patient’s ability to eat enough to supply nutritional requirements.

Early satiety is frequently experienced by cancer patients. Delayed gastric emptying or decreased gastric transit time may contribute to the patient’s inability to eat enough. Problems patients experience with gastrointestinal discomfort may be important quality-of-life issues for many patients.(1–4) Thus nausea and vomiting, diarrhoea, cramping, bloating, flatulence, and general discomfort associated with eating may lead to inadequate nutrition. When these symptoms occur, the health professional should encourage the use of of antiemetic, antidiarrhoeal, orexigenic (appetite enhancers), and pain medication.(5,6) The drugs now readily available for nausea, queasiness, and appetite stimulation should be made available to patients.

Mucositis, stomatitis and oral pain can make eating difficult. The physical discomfort caused by the irritation of eating may discourage patients from consuming enough, as can dry mouth, poor dentition, and dysphagia. Oral analgesics, topical anaesthetics, antifungal medication and ice chips may provide symptomatic relief.(7)

Patients frequently develop an aversion to the taste and smell of food as a result of negative food experiences during or after antineoplastic therapy. The patient associates the adverse response with the food, rejecting the item when offered it again. Determining the nature of chewing or swallowing difficulty may provide appropriate solutions, such as a change in consistency, texture, or amount taken with each mouthful and during each meal.

The effort to prepare or consume the food or the lack of strength to cut, chew or manipulate the utensils or food items may deter the patient from eating. Every effort should be made to assist the patient in the hospital at mealtime. Volunteers or aides should be assigned to open containers, cut foods, and position the patient properly and comfortably for eating. The discharge plan should include arrangements to assist and support the patient and prevent physical deterioration after discharge. Companions, cancer care aides, or another home-bound service agency may be invaluable resources for cancer patients who struggle to cope with the demands of care at home.

Pain, from the disease itself or from the effects of treatment, can affect the desire and ability to eat. Symptomatic pain relief can be provided at mealtimes with proper dosing and scheduling of medications. If the patient is suffering from uncontrolled pain, a pain consultation may be needed.

Fear, anxiety and depression often alter the behaviour and attitude of the patient and loved ones. One response to a devastating illness is rejection of things that nourish and nurture. If the patient is not coping well, psychiatric, spiritual, or social work consultation should be sought. The managing physician or another team member may need to organise a consultation. Multidisciplinary rounds may be a good time for the issue to be raised.

Tumours in the gastrointestinal tract can obstruct passage of nutrients or limit the patient’s capability of eating. Tumours outside the gastrointestinal tract such as metastatic ovarian cancer can also compromise nutrition by pressing on the gastrointestinal structures and causing obstruction with the same results: inadequate intake, early satiety, and anorexia or cachexia. Tumours can also cause anorexia and cachexia secondary to remote systemic or central nervous system effects.

The significant roles of diet and nutrition throughout the clinical course of cancer must also be recognised. During the past 15 years, several articles have supported what many who work with this population already know, that some 40–80% of all cancer patients develop some degree of clinical malnutrition.(8–10) Cancer anorexia–cachexia syndrome may be present at the time of death in 80% of cancer patients.(11) The clinical effects of poor nutrition are manifested in poor wound healing and poor skin turgor leading to skin breakdown and decubiti. Anastomotic leaks, wound dehiscence, electrolyte and fluid imbalances, and endocrine abnormalities are common in this population, as is compromised immune function.(10) The risk of malnutrition and its degree are affected by tumour type, stage of disease, and antineoplastic therapy.

Nutrition support modalities
When possible, a nutrition plan should provide the feeding regimen most comfortable for the patient. Oral intake is the most acceptable method of feeding, but it might have to be modified from standard meals or food choices. Most patients do best with six small feedings instead of three large meals. By providing small frequent feedings throughout the day and evening, the caregiver can select foods that might be easily tolerated in small mouthfuls and consumed with less effort than large imposing plates of food. If early satiety, decreased appetite, or queasiness is causing poor intake, calorie-dense food choices should be offered. Patients need to be re-educated about food choices. Priorities must be revised. Information previously given about healthy eating may no longer be appropriate. Many patients try to avoid fat and eat lots of fruits, vegetables and fibre because public health messages promote such a diet to prevent disease and ensure wellness. Patients and family members must appreciate that a starving cancer patient’s needs are different.

Concern about cholesterol, fats, and artificial colours and flavours should not deter a person from eating whatever provides the needed calories, protein, and nutrients. Favourite foods should be encouraged. Supplements and high-calorie, nutritious snacks can augment a limited food regimen. Every effort should be made to maintain adequate nutrition orally. The food preparer can use cream, butter or trans-fat-free margarine, cheese, and other high-calorie sources to increase calories without affecting portion sizes. Suggesting high-calorie snacks such as peanut butter crackers, chocolates, cheese Danish, rice pudding with whipped cream, custards made with rich ingredients, rich ice cream, or chips with sour cream dip encourages the patient to seek out appealing foods that, even eaten in small quantities, are loaded with calories. These foods might not be eaten without the dietitian’s recommendation, as weight- or health-conscious family members might be avoiding them.

Once a patient who has been given every opportunity to meet nutrition needs by oral means has failed to do so, enteral management should be implemented as soon as possible. Because the goal of nutrition support should be to prevent malnutrition rather than to reverse it, early intervention is crucial. If the problem that prevents adequate intake is deemed to be an acute, short-term condition, a nasoenteric tube may be the feeding method of choice.(12) Although it is a low-risk procedure and the tube is easy to insert, the patient is usually self-conscious, uncomfortable, and resistant to it. For short-term management it can be very effective once the patient is able to relax and adjust to having the tube in the throat.

If enteral support is expected to last four weeks or longer, an enterostomy is suggested. With the advent of the percutaneous, endoscopically-placed gastrostomy (PEG) procedure, patients can be given a feeding tube in an outpatient procedure and sent home the same afternoon. PEG feeding allows patients to resume whatever lifestyle or activities they are able to perform without the stigma and limitations of the feeding tube. The procedure is relatively safe, easy for a skilled endoscopist, and a very effective means of meeting otherwise unattainable nutrition requirements.(13,14) PEG insertion can be adapted to the patient’s needs with modifications that allow the gastrointestinal tract to be used even if normal flow of food through the gastrointestinal tract is obstructed or otherwise limited.(15) This method is very effective for patients with mechanical or physical limitations of the head, neck or oesophagus. Patients who are anorexic or unable to eat adequately also find PEGs to be the answer to their nutrition problems. Although many physicians prefer total parenteral nutrition for patients who are malnourished, using the gastrointestinal tract is physiologically sounder, safer and less costly.

Surgically placed enterostomy tubes are effective when placed at the time of a surgical procedure. For patients whose diagnosis or treatment modalities interfere with adequate nutrition, providing a feeding tube during surgery affords the clinician the option, at any time during the early postoperative course, to institute tube feeding of all or part of the patient’s nutrient needs.(16) Placing the tube during the surgical procedure spares the patient endoscopic placement. Many surgeons are reluctant to place a tube prophylactically into patients who may not use it, but many types of cancer and therapy are associated with high risk of malnutrition so the likelihood of a given patient needing enteral support is good. Studies by numerous investigators reveal growing appreciation for the benefits of early enteral feeding after a surgical procedure with respect to acute-phase response to trauma, stress, and the other manifestations of major surgery.

Most absorption normally occurs in the first third of the jejunum, so a gastric tube affords a physiological advantage. In addition, with gastric feeding, gastric secretions, bile acid, and pancreatic enzymes have more time to mix with the bolus of food. When the stomach cannot be used, a jejunostomy feeding tube can be placed. Jejunostomies can be placed endoscopically either as an in- or outpatient procedure or surgically. Endoscopic placement is technically more difficult but can be performed by a skilled endoscopist.(17) Management of the jejunostomy requires modification of the standard gastrostomy procedure. Adjustments of rate, administration, and type of feeding and tolerance must be considered.

Feeding modalities
The typical feeding modalities: bolus, intermittent or gravity drip, pump-assisted, continuous slow infusion-for enteral formulas are chosen by the same criteria as for any other enterally-fed patient.(12,18,19) The patient should be evaluated to determine if intermittent or pump-assisted feedings would serve them better than a bolus. Pump-assisted feedings were emphasised in the 1980s to heighten the awareness of institutions not already using continuous feeding for patients who could benefit from it. However, with the increased use of PEGs for patients with anorexia or physical or mechanical limitations, the need for pump-assisted, slow-drip feeding has diminished. For the many patients using enteral feedings in home or outpatient settings, bolus feedings are much more convenient and adaptable to their caregivers and their schedules. Bolus feeding is logistically simpler and of nominal cost. Many patients at home prefer to feed themselves while they sleep, so as to be unencumbered during the day. Pump-assisted night feedings allow these patients to go about their daily activities without the feeding interfering.

If tube feedings are being used in conjunction with oral feeding patients may decrease their enteral volume in the belief that they are eating enough when in fact they are eating considerably less than they need. They should be encouraged to sustain the volume of enteral formula, regardless of oral consumption. If they prove that weight gain is occurring as a result of the combined intake, they can decrease enteral intake for 7–10 days as a trial and be monitored for response. If the patient does well, enteral volume can be adjusted appropriately. The possibility of nutritional decline, however, must be addressed before severe malnutrition occurs.

For many nutrition professionals who have worked with severely malnourished patients, the failure to renourish these individuals, even with hypercaloric feedings enterally or parenterally is a common experience. Recently, several novel approaches have been attempted. Appetite stimulants such as megestrol acetate, medroxyprogesterone, and dronabinol have shown potential in increasing intake or appetite although failed to increase lean body mass and improve quality of life. In an effort to increase lean body mass and reverse further protein breakdown, anabolic agents such as anabolic steroids, recombinant human growth hormone or testosterone have been used in cachectic patients. In some situations human growth hormone did improve functional status but its use with cancer patients is troublesome for fear of tumour growth. Another concern with growth hormone is its negative effect on the acute-phase response thus interfering with the body’s natural defences.

Anabolic agents are being studied as preliminary results have shown increases in fat-free mass and weight gain when given with increased protein intake. Anticytokine therapy is a logical approach to inhibit protein breakdown and proinflammatory activity. Emerging therapies include pentoxifylline which can lessen the effect of tumour necrosis factor (TNF), one of the identified cytokines produced during the acute phase response. Another emerging agent is thalidomide which can degrade the messenger RNA of TNF. Another exciting therapy involves the anti-inflammatory effect of omega-3-fatty acids by altering the release of cytokines. This effect has been shown to be effective in nonmalignant cachexia such as with rheumatoid diseases. However, recently several investigators have shown that eicosapentaenoic acid (EPA) along with increased calories and protein in a supplemental drink was able to increase total caloric and nutrient intake, lower resting energy expenditure while performance status and appetite were improved in advanced pancreatic cancer patients studied short-term.(20,21) See Resources for some useful sources of further information.

References

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6. Herrington AM, et al. Nutr Clin Pract 1997; 12:101-13.
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11. Nelson KA. Semin Oncol 2000;27(1):64-8.
12. Piazza-Barnett R, Matarese L. In: McCallum PD, Polisena CG, editors. The clinical guide to oncology nutrition. Chicago: ADA; 2000. p.106-18.
13. Levy H. In: Shike M, Bloch AS, editors. Gastrointestinal endoscopy clinics of North America. Philadelphia: WB Saunders; 1998. p. 529-50.
14. Safadi BY, et al. In: Shike M, Bloch AS, editors. Gastrointestinal endoscopy clinics of North America. Philadelphia: WB Saunders; 1998. p. 551-68.
15. Kirby DF, Teran JC. In: Shike M, Bloch AS, editors. Gastrointestinal endoscopy: clinics of North America. Philadelphia: WB Saunders Co; 1998. p. 623-44.
16. Georgeson K, Owings E. In: Shike M, Bloch AS, editors. Gastrointestinal endoscopy: clinics of North America. Philadelphia: WB Saunders; 1998. p. 581-92.
17. Shike M, Latkany L. In: Shike M, Bloch AS, editors. Gastrointestinal endoscopy: clinics of North America. Philadelphia: WB Saunders; 1998. p. 569-80.
18. Charney P. In: Gottschlich MM, et al, editors. The science and practice of nutrition support: a case-based core curriculum. Dubuque, IO: Kendall/Hunt Publ; 2001. p. 141-66.
19. Bloch AS, Mueller C. In: Mahan LK, Escott-Stump S, editors. Krause’s food, nutrition, and diet therapy. Philadelphia: WB Saunders; 2000. p. 463-82.
20. Barber MD, et al. Br J Cancer 1999;81:80-6.
21. Wigmore SJ, et al. Nutr Cancer 2000; 36:177-84.

Resources
American Institute for Cancer Research
W:http://www.aicr.org
National Cancer Institute (NCI)
W:http://www.cancer.gov
Cancer Information Service (CIS)
W:http://cis.nci.nih.gov
Memorial Sloan-Kettering Cancer Center About Herbs
W:http://www.mskcc.org/mskcc/html/11570.cfm