- Email: [email protected]
Nutrition support in cancer
122
S e m i n a r s in Oncology Nursing, Vol 16, No 2 (May), 2000: pp 122-127
OBJECTIVES: To describe nutrition intervention strategies frequently used to support cancer patients experiencing malnutrition.
NUTRITION SUPPORT IN CANCER
DATA SOURCES: Textbook chapters, database reports, and current related literature.
CONCLUSIONS: Clinicians have m a n y options f o r providing nutrition support interventions f o r the cancer patient at risk f o r malnutrition. The most appropriate strategyjbr a patient should be based on a carefid assessment of contributing factors w i t h input f r o m a muhidiseiplinary team.
IMPLICATIONS FOR NURSING PRACTICE: It is important f o r nurses to be knowledgeable about nutrition intervention options available to patients at various points along the cancer trajectory. Oncotogy nurses are in a key position to provide support to patients and families w i t h regard to nutrition issues. Of p a r a m o u n t importance is their contribution to ongoing a s s e s s m e n t of nutritional status and early and aggressive intervention to meet nutritional needs.
From Ne~ ~brk, NY.
Abby Bloch,PhD, RD, FADA:Nutrition Consultant, New York, NY. Address reprint requests to Abby Bloeh, PhD, RD, FADA, Nutrition Consuhant, 340 E 64thSt, 12-N, New York, NY10021.
Copyright ©2000 by tEB. Saunders Company 0749-2081/00/1602-0006510.00/0 doi: l O.1053/on.2000.5555
ABBY BLOCH
I
T HAS BEEN estimated that between 40% and 80% of all cancer patients develop some degree of clinical malnutrition during their illness. 1,2 Patients with advanced cancer often suffer from protein-calorie depletion. The clinical effects of poor nutrition are manifested in poor wound healing, poor skin turgot leading to skin breakdown, and decubiti. Anastomotic leaks and wound dehiscence, along with electrolyte and fluid imbalances, endocrine abnormalities, and compromised immune function are common and can result in increased morbidity and mortality_3 Maintenance of optimal nutritional status is essential to avoid substantial nutrient deficits, weight loss, and the accompanying clinical consequences that can adversely affect outcome. A patient's nutritional status is affected by tumor type, stage of disease, and antineoplastic therapy. 4 Over the past two decades greater attention has been focused on strategies to manage the malnutrition that frequently accompanies a cancer diagnosis. As a result of increased knowledge and experience, snbstrates used to provide nutrition support have been greatly improved and expanded. In addition, technologic advances have contributed to new and varied delivery systems, simplifying the administration of many of these therapies .5 This article reviews options for providing adequate nutrition support for cancer patients. Three areas will be highlighted: the goals of nutrition support in the cancer patient; oral, enteral, and parenteral approaches to nutritional support; and pharmacologic influences on nutritional status, including the use of orexigenic agents to stimulate appetite and support nutrition in this population. NUTRITION SUPPORT IN THE CANCER PATIENT he determination of a given patient's nutritional needs begins with a comprehensive assessment of the factors contributing to T their specific clinical situation. Nutritional screening, the first step in this process, is necessary to determine nutritional risk and
NUTRITION SUPPORT INTERVENTIONS IN CANCER
facilitate identification of deficits early in the course of t r e a t m e n t . The result of this process is the categorization of patients into low-, moderate-, or high-risk groups. Screening tools should be oneology-specifie and have established validity and reliability for use in the c a n c e r population. Several examples of such i n s t r u m e n t s have been described in the literature_ 6s Weight is one of the m a j o r variables used to d e t e r m i n e nutritional risk. Significant weight loss (>10%) m a y be p r e s e n t in ->45% of all adult hospitalized c a n c e r patients. 9 The c o n s e q u e n c e s of significant weight loss and malnutrition have been well documented. 3,1°-12
Goals and Benefits of Nutrition Support The goals of nutritional interventions in the c a n c e r patient are to support anabolism and body composition, functional status, and quality of life. 13 A proactive a p p r o a c h to nutritional care is essential in ensuring that these goals are achieved. Historically, clinicians have viewed nutritional issues as low on the list of priorities. This perception leads to a reactive/repletion mode, which is often futile. Nutrition interventions m u s t be instituted early to be successful. Providing nutrition support is associated with a n u m b e r of benefits. Increases in weight, anthropometric m e a s u r e m e n t s , and s e r u m a l b u m e n have all been d o c u m e n t e d as a result of nutrition support interventions, as have i m p r o v e m e n t s in nitrogen balance and i m m u n e function. 14
Support Via the Oral Route The patient diagnosed with c a n c e r needs to m a k e every effort to sustain nutritional a d e q u a c y and m e e t caloric and nutrient r e q u i r e m e n t s via the oral route. Appetite m a y wane, pain m a y interfere with eating, or the disease process m a y affect the patient's ability to c o n s u m e adequate calories to m e e t nutritional requirements. In such cases, modification in caloric density, volume of food at each feeding, and s u p p l e m e n t s to a u g m e n t total intake m a y be required. Separation of fluids and solids m a y p r e v e n t early satiety or d u m p i n g s y m p t o m s . Pain, nausea, and other s y m p t o m s that have the potential to interfere with nutritional intake should be aggressively managed. An issue that is frequently raised by patients or family m e m b e r s is that of dietary restrictions. Patient a d h e r e n c e to restrictions m a y decrease the caloric intake that is so essential. No specific guidelines for caloric or dietary restrictions exist
123
for this population. In m o s t cases, dietary restrictions can be eliminated. C o n c e r n about cholesterol, fats, and artificial colors and flavors should not affect the c a n c e r patient's decision to select foods or products that might assist in meeting caloric and nutritional goals. Patients often refuse to use nutritional s u p p l e m e n t s that would augm e n t an inadequate caloric intake for fear of the artificial ingredients found in the product. Appropriate patient education is w a r r a n t e d in helping patients u n d e r s t a n d these issues. W h e n food c o n s u m p t i o n b e c o m e s inadequate, oral intake m a y need to be s u p p l e m e n t e d to m e e t caloric requirements. Two a p p r o a c h e s to nutrition s u p p l e m e n t a t i o n should be considered at this juncture: the enteral and p a r e n t e r a l routes of administration.
The Enterai Approach Alternative nutrition support via the enteral route should be p u r s u e d if adequate calories e a n n o t be c o n s u m e d by mouth. A variety of physiologic benefits are associated with the continued stimulation of the gut that occurs w h e n the enteral a p p r o a c h is used. Enteral nutrition prevents a t r o p h y of the mierovilli lining the intestinal wall, which can occur within a few days of diminished oral intake; this leads to changes in intestinal flora and histology, predisposing the patient to additional complications. Enteral tube placement. Most nutrient absorption occurs in the first third of the j e j u n u m , making p l a c e m e n t of the feeding tube in the s t o m a c h physiologically advantageous. This app r o a c h allows gastric secretions, bile acid, and p a n c r e a t i c e n z y m e s to mix with the bolus of food or formula as it passes from the s t o m a c h into the d u o d e n u m and jejunum. W h e n a patient's limitation in oral intake is projected to be of short duration, nasoenteric tube p l a c e m e n t m a y be the preferred m e t h o d of enteral access. Although this a p p r o a c h is c o n v e n i e n t and relatively simple, patients m a y be u n c o m f o r t a b l e with a p p e a r e n c e and the process of tube placement. In clinical situations in which the limitation in oral intake is e x p e c t e d to persist for m o r e than several weeks, an e n t e r o s t o m y is r e c o m m e n d e d . 15 Percutaneous, endoseopically placed g a s t r o s t o m y (PEG) or j e j u n o s t o m y feeding tubes are excellent options for long-term enteral support. The PEG feeding tube is especially effective for patients with m e c h a n i c a l or physical limitations of the head,
124
ABBY BLOCH
neck, or esophagus. In addition, those who experience anorexia, early satiety, or queasiness can also benefit substantially by using the PEG feeding tube to supplement oral intake. 16 Pereutaneous, endoseopically placed gastrostomy tube placement can be readily accomplished in the outpatient setting. Initially, a 24- to 28-French, 8- to 14-inch catheter will be inserted. After several weeks, this is replaced with a skin-level, low-profile feeding device. These flat devices, also known as buttons, allow the individual to resume a more normal lifestyle. Patients can wear tight-fitting clothes again, take showers, feel more comfortable with sexual activity, and have a more positive self-image. The jejunum may be used as an alternate location for feeding tube insertion when placement in the stomach is contraindicated. Jejunostomies are placed using endoscopic techniques similar to those used with PEG feeding tube insertions. 17 Nutritional support through jejunostomy tubes accesses the small bowel directly, bypassing exposure to gastric secretion and enzymes. Feeding contents and procedures need to be adjusted based on individual patient need. Once a PEG or jejunostomy feeding tube is in place, patients can continue to consume foods by the oral route for enjoyment purposes or social interaction. This knowledge often provides a level of comfort and a sense of normality for both patients and family members_
Administration strategies for enteral feedings. Several options for administering enteral formulas are available; the most common approaches are intermittent bolus and continuous feedings. If the gastrointestinal tract is intact, bolus feedings are the most appropriate approach, is Bolus feedings are easy to manage, require little equipment, and are relatively inexpensive. Flexibility in feeding schedules and ease in administration contribute to the appeal of this method. The timing of bolus feeding, for example, can mimic the routine of regular meals, which may provide a psychological benefit for patients. Patients should be instructed, however, that bolus meals should be consumed slower than regular meals to ensure maximum digestibility and absorption_ If the gastrointestinal tract is physiologically unable to tolerate bolus feedings or if the patient prefers to feed at night while sleeping, intermittent gravity or pump-assisted continuous slow-infusion
approaches are available. These methods require additional equipment and closer monitoring than bolus feedings. Gravity feedings must be adjusted to allow the formula to flow at a rate that is tolerated by the patient. Pump-assisted feedings require training of all involved in earing for the patient_ If members of the family are out of the home during the day, pumpzassisted feedings during the evening or at night might be easier to manage. Planning should include consideration of family members' schedules and commitments to ensure proper adherence to the feeding schedule. Enteral formula selection. Enteral formulas should be selected based on the following criteria: (1) gastrointestinal function; (2) physical characteristics of the formula, such as viscosity, osmolality, fiber content, and caloric density; (3) macronutrient content; (4) digestion, absorption, and utilization capability; (5) specific metabolic needs; (6) electrolyte and fluid requirements; and (7) financial concerns. Formulas are generally classified by macronutrient composition_ General purpose formulas, also called intact or polymeric formulas, contain biologically complete, intact protein such as easeinate, laetalbumin, beef, and soy protein. These formulas are well-tolerated by most patients. If a higher protein content or caloric density greater than 1 kcal/mL is desired, or if lactose-intolerance, volume limitations, or gastric discomfort exists, appropriate modifications or adjustments may be made based on clinical status and tolerance. Patients who are unable to digest or absorb intact protein may be given peptide fragments (dipeptides, tripeptides, or oligopeptides) and amino acids derived from hydrolysis of casein, whey, lactalbumin, or soy; these are also known as monomeric formulas. Such predigested monomeric formulas are indicated when a metabolic abnormality or clinical condition such as shortbowel syndrome exists. Moreover, disease-specific formulas are commercially available for patients who have renal, hepatic, and cardiopulmonary disease, metabolic stress, immunosuppression, or glucose intolerance. New formulas are being developed based on evolving nutrition research. 19The type and amount of fats added to enteral products are being modified. Antioxidants and micronutrients are being included to enhance formulas. As genetic research unfolds and metabolic characteristics of
NUTRITION
m a n y types of cells are revealed, specially formulated n u t r i e n t substrates will b e c o m e available_ s For the present, formula selection should be d e t e r m i n e d on an individualized basis. Since this process is complex, enlisting the aid of a trained dietary specialist is r e c o m m e n d e d . In the c a n c e r population, the need to obtain adequate calories is paramount_ Protein needs and other nutrients are important, but calorie requirem e n t s m u s t be m e t before the c a n c e r patient will show a weight response to nutrition support. Even w h e n appropriate enteral formulas are prescribed, the patient m a y not actually c o n s u m e enough to ensure weight m a i n t e n a n c e or gain. If this deficiency is not detected quickly, the patient can b e c o m e malnourished_ Clinieians need to evaluate actual daily intake and patient weight in a routine a n d systematic m a n n e r and m a k e changes as needed to ensure the success of the nutrition care plan.
The Parenterai Approach When the clinical situation precludes use of the gastrointestinal tract for feeding, total parenteral nutrition (TPN) should be considered. -'° Data on the use of TPN in eaneer are inconsistent21-e-~ Klein et a124 reviewed 28 prospective controlled trials evaluating the use of TPN in c a n c e r patients. These authors pooled data across studies a n d concluded that TPN m a y be useful in certain subsets of o n t o l o g y patients treated surgieally_ In patients treated with c h e m o t h e r a p y , however, no significant benefit in terms of survival, t r e a t m e n t tolerance, t r e a t m e n t toxicity, or t u m o r response was appreciated. In addition, an increased risk of developing infection was demonstrated. More recently, McGeer et al, 25 u n d e r the auspices of the A m e r i c a n College of Physicians, c o n d u c t e d a review of published TPN trials using recta-analytic techniques. When data from all trials were compiled, patients who had received c h e m o t h e r a p y and TPN versus c h e m o t h e r a p y alone d e m o n s t r a t e d an odds ratio of 0.81, ie, the survival of this group was only 81% as long as patients who received no TPN. In contrast, there have b e e n some studies in which advantages of TPN in specific populations have b e e n demonstrated. In one study, perioperativc TPN increased body weight, s e r u m proteins, i m m u n e function, and nitrogen balance. However, reduced postoperative complications or mortality were not seen. 2~ Based on a lack of consensus in the literature, it
SUPPORT INTERVENTIONS
IN CANCER
125
s e e m s that the routine use of TPN in t h e c a n c e r population is not justified_ 22 This modality should be used after careful consideration of an individual patient's risk and benefit. Table I provides a list of clinical situations in which it would be appropriate to use TPN_ W h e n used, p a r e n t e r a l formulas should contain adequate a m o u n t s of h y p e r t o n i c glueose, protein, fat emulsion, vitamins, electrolytes, and minerals to m e e t individualized patient nutritional needs. If not contraindicated, oral intake should be encouraged in conjunction with TPN for gut stimulation.
PHARMACOLOGIC ISSUES A
discussion of nutrition support in the c a n c e r patient would be i n c o m p l e t e without attention to pharmaeologie considerations. Medications frequently used in the c a n c e r population have the potential to alter nutritional parameters. Malabsorption m a y result from antineoplasties or other pharmacologic agents (Table 2). 27 I m p a i r e d digestion and absorption s e c o n d a r y to the use of these agents should not be overlooked as a possible cause of c o m p r o m i s e d nutritional status. Clinicians should b e c o m e familiar with m e t a bolic alterations associated with new agents. Moreover, when drugs are used in c o m b i n a t i o n protocols, the synergistic effects of these agents should to be considered.
Orexigenic Agents A n u m b e r of agents have been evaluated for their ability to increase the appetite in c a n c e r patients.2S 51 Investigations of eorticosteroids have d e m o n s t r a t e d limited effects on food intake, well-being, and p e r f o r m a n c e status. These agents m a y improve appetite indirectly by decreasing nausea and asthenia and improving pain control. However, the side effect profile of eortieosteroids TABLE
1.
Indications for the Use of Parenteral Support Severe malnutrition not corrected by enteral support Chronic malabsorption, severe diarrhea Short-bowel obstruction
High-output fistula Short-bowel secondary to bypass surgery Radiation enteritis Anticancer therapy will be compromised if malnutrition interferes with treatment schedule
126
ABBY BLOCH
i:ii:::Agents Commorliy P r e ~ r ~
:::::::Drug
.......
In the Cancer
..... : Nutritional Alteration :: : ........
.
.
.
.
.
.
.
Hyperglycem a hemorrhagic pan~ ::: :: : : : : . . . . creatitis . . . . . . : : ........ Chlorot#.an~sene Hyerca~emia:;: ......: : : ::::: Ci~i~tin ..... Hypeparfcemia, t!ypornagnesem~a :: Corti~steroids :: Sodium retention; potassium ~cal:::i ::: cium, magnesium and z i n c : excretion; hyperglycemia i: Diethylstilbestrol Hypercalcemia : Methotrexate :Folate and ca!cium :deflc~n ~ : Mithrarnycin Hypocalcem a, hypokalemia Sireptozocin .............. Sudden hypoglycemia ......... Tamoxifen Hypercalcemia :: Paclitaxef .... Nauseal vomiting, mucositis Treti~!n =Iall.trans Hypertdglycer~demia, elevated re~3noic acid) .... liver function tests VinCiistine Inappropriate ant d uret c hop mone secretion, hyponatremia, water retention, decreased serum osmolality, increased urine osmolality .....
some positive results, 29 but no substantial benefits were reported in any of the larger controlled trials investigating this agent. 33-35 The cannabinods, dronabinol and nabilone, have been tested in several populations. Two open studies 36,37 resulted in improvements in mood and appetite, but no significant effect on body weight gain was observed_ Additional trials are needed to determine how these agents should be used in the cancer population. Megestrol acetate, a progestational agent, has shown promise in several trials in which it was studied. Megesterol has demonstrated a doserelated benefit on appetite, caloric intake, bodyweight gain (primarily fat) 38,39 and sensation of well-being with an optimal dose of 800 mg/d administered orally. 4° Drugs to increase muscle mass, such as oxandrolone, growth hormones, and medroxyprogesterone acetate, are also becoming popular. Newer agents being studied are melatonin, thalidomide, omega-3 fatty acids, ~2-adrenoceptor agonists, synthetic analogs of anabolic-androgenic steroids, and anticytokine therapies. 29,41
CONCLUSION
and their potential to exacerbate muscle deterioration secondary to urinary protein losses preclude routine use of these agents. 29 Cyproheptadine, an antihistamine, has been used in Europe as an appetite stimulant. A controlled trial conducted in the United States, however, failed to demonstrate improvements in body weight or improved nutritional status in the patients who took it. 32 Hydrazine sulfate has been used as an inhibitor of gluconeogenesis. Smaller trials have shown
lterations in nutritional status are an integral part of the disease process of cancer. 42 Nutrition plays a significant role throughout the clinical course of this process. Clinicians have many options for providing adequate nutrition to the patient at risk for becoming malnourished. They must be encouraged to take advantage of these options by intervening early and aggressively to meet the nutritional needs of patients who struggle with their meals and food intake.
A
REFERENCES 1. Kern I(A, Norton JA: Cancer eaehexia. J Parenter Enteral Nutr 2:286-298, 1988 2. Ollenschlager G, Viell B, Thomas W, et al: Tumor anorexia: Causes, assessment, treatment. Recent Results Cancer Res 121:249-259, 1991 3. Shils ME: Nutrition and diet in cancer management, in Shils ME, Olson J, Shike M (eds): Modern Nutrition in Health and Disease. Philadelphia, PA, Lea & Febiger, 1994, pp 1317-1348 4. Shike M, Brennan MF: Supportive care of the cancer patient, in DeVita VT, Hellman S, Rosenberg SA (eds): Cancer: Principles and Practice in Oncology. Philadelphia, PA, Lippincott, 1989, pp 2029-2044
5. Dudrick SJ: Past, present, and future of nutrition support. Surg Clin North Am 71:439-448, 1991 6. Detsky AS, McLaughlin JR, Baker JP, et al: What is subjective global assessment of nutritional status? J Parenter Enteral Nutr 11:8-13, 1987 7. Ottery FD: Cancer cachexia prevention, early diagnosis, and management. Cancer Praet 2:123-131, 1994 8. Memorial Sloan-Kettering Cancer Center Adult Oneology Screening Tool, Clinical Dietitian Staff 1994-1995. New York, NY, Food Service Department, Memorial Sloan-Kettering Cancer Center, 1995 9. Shils ME: Principles of nutritional therapy. Cancer 43:2093-2102, 1979
NUTRITION SUPPORT INTERVENTIONS IN CANCER
10. Chlebowski RT: Nutritional support of the medical oneology patient. Hematol Oneol Clin North Am 5:147-160, 1991 11. Hansell DT, Davies JW, Shenkin A, et al: The oxidation of body fuel stores in cancer patientsl Ann Surg 204:637-642, 1986 12. Hansell DT, Davies JW, Burns HJ: The relationship between resting energy expenditure and weight loss in benign and malignant disease. Ann Surg 203:240-245, 1986 13. Ottery FD: Supportive nutrition to prevent eaehexia and improve quality of life. Semin Oneol 22:98-111, 1995 (suppl 3) 14. Nixon DW: The value of parenteral nutrition support. Cancer 58:1902-1903, 1986 15. Shike M, Bloeh AS: Enteral nutrition. Gastrointest Endose Clin North Am 8:529-744, 1998 16. Kirby DF, Teran JC: Enteral feeding in critical care. Gastrointestinal disease and cancer. Gastrointcst Endose Clin North Am 8:623-643, 1998 17. Shike M, Latkany L: Direct percutaneous endoscopic jejunostomy. Gastrointest Endose Clin North Am 8:569-580, 1998 18. tteber D, Blackburn GL, Go VLW: The Principles of Nutritional Oneology. San Diego, CA, Academic, 1999 19. Matarese LE: Enteral feeding solutions. Gastrointest Endosc Clin North Am 8:593-610, 1998 20. Chan S, Blackburn GL: Total parenteral nutrition in eaneer patients, in Heber D, Blackburn GL, Go VLW (eds): Nutrition ()neology. San Diego, CA, Academic, 1999, pp 573-580 21. American College of Physicians: Parenteral nutrition in patients receiving cancer chemotherapy. Ann Intern Med 110:734-736, 198q 22. Klein S, Koretz RL: Nutritional support in patients with cancer: What do the data really show? Nutr Clin Praet 9:91-100, 1994 23. Bloeh AS: Feeding the cancer patient: Where have we eome from, where are we going~ Nutr Clin Praet 9:87-89, 1994 24. Klein S, Simes J~ Blackburn GL: Total parenteral nutrition and cancer clinical trials. Cancer 58:1378-1386, 1986 25. McGecr AJ, Detsky AS, O'Rourke K: Parenteral nutrition in cancer patients undergoing chemotherapy: A meta-analysis. Nutrition 6:478-483, 1990 26. Daly JM, Shinkwin M: Nutrition and the cancer patient, in Murphy GP, Lawrence W, Lenhard RE (eds): American Cancer Society Textbook of Clinical Oncology. Atlanta, GA, American Cancer Society, 1995, pp 580-596 27. Bloch AS: Cancer, in Matarese LE, Gottschlich MM (eds): Contemporary Nutrition Support Practice: A Clinical Guide. Philadelphia, PA, Saunders, 1998, pp 475-495
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28. Herrington AM, Herrington JD, Church CA: Pharmacologic options for the treatment of eaehexia. Nutr Clin Pract 12:101-113, 1997 29. Gagnon B, Bruera E: A review of the drug treatment of cachexia associated with eaneer. Drugs 55:675-688, 1998 30. Ottery FD, Walsh D, Strawford A: Pharmacologic management of anorexia/cachexia. Semin Oncol 25:35-44, 1998 (suppl 6) 31. ttaslett PA: Anticytokine approaches to the treatment of anorexia and eachexia. Semin Oncol 25:53-57, 1998 (suppl 6) 32. Kardinal CG, Loprinzi CL, Schaid DJ, et al: A controlled trial of eyproheptadine in cancer patients with anorexia and/or eachexia. Cancer 65:2657-2662, 1990 33. Loprinzi CL, Juross SA, O'Fallon JV, et al: Randomized, placebo-controlled evaluation of hydrazine sulfate in patients with advanced colorectal cancer. J Clin Oneol 12:1121-1125, 1994 34. Loprinzi CL, Goldberg RM, Su JQ: Placebo-controlled trial of hydrazine sulfate in patients with newly diagnosed non-small-eell lung cancer. J Clin Onco112:1126-1129, 1994 35 Kosty MP, Fleishman SB, Herndon JE, et al: Cisplatin, vinblastine and hydrazine sulfate in advanced non-small-cell lung cancer: A randomized placebo-controlled, double-blind phase III study of the cancer and leukemia group B. J Clin Oncol 12:1113-1120, 1994 36. Wadleigh R, Spaulding M, Lembersky B, et al: Dronabinol enhancement of appetite in cancer patients. Proe Am Soe Clin Oncol 9:331, 1990 (abstr) 37. Nelson K, Walsh D, Deeter P, et al: A phase II study of delta-nine-tetrahydroeannabinol for appetite sumulation in cancer associated anorexia. J Palliat Care 10:14-18, 1994 38. Loprinzi CL, Sehaid DJ, Dose AM, ct al: Bodycomposition changes in patients who gain weight while receiving megestrol acetate. J Clin Oneol 11:152-154, 1993 39. Oster MH, Enders SR, Samuels SJ, et al: Megestrol acetate m patients with AIDS and caehexia. Ann Intern Med 121:400-408, 1994 40. Loprinzi CL, Miehalak JC, Sehaid DJ: Phase three evaluation of four doses of megestrol acetate as therapy for patients with cancer anorexia and/or caehexia. J Clin Oncol 11:762-767, 1993 41. Nash TM: Use of anabolic agents in patients with cancer caehexia. Support lane 21:14-18, 1999 42. Heber D, Blackburn GL, Go VLW: Introduction: The principles of nutritional oncology, in Heber D, Blackburn GL, Go VLW (eds): Nutritional Oneology. San Diego, CA, Academic, 1999. pp 1-10
S e m i n a r s in Oncology Nursing, Vol 16, No 2 (May), 2000: pp 122-127
OBJECTIVES: To describe nutrition intervention strategies frequently used to support cancer patients experiencing malnutrition.
NUTRITION SUPPORT IN CANCER
DATA SOURCES: Textbook chapters, database reports, and current related literature.
CONCLUSIONS: Clinicians have m a n y options f o r providing nutrition support interventions f o r the cancer patient at risk f o r malnutrition. The most appropriate strategyjbr a patient should be based on a carefid assessment of contributing factors w i t h input f r o m a muhidiseiplinary team.
IMPLICATIONS FOR NURSING PRACTICE: It is important f o r nurses to be knowledgeable about nutrition intervention options available to patients at various points along the cancer trajectory. Oncotogy nurses are in a key position to provide support to patients and families w i t h regard to nutrition issues. Of p a r a m o u n t importance is their contribution to ongoing a s s e s s m e n t of nutritional status and early and aggressive intervention to meet nutritional needs.
From Ne~ ~brk, NY.
Abby Bloch,PhD, RD, FADA:Nutrition Consultant, New York, NY. Address reprint requests to Abby Bloeh, PhD, RD, FADA, Nutrition Consuhant, 340 E 64thSt, 12-N, New York, NY10021.
Copyright ©2000 by tEB. Saunders Company 0749-2081/00/1602-0006510.00/0 doi: l O.1053/on.2000.5555
ABBY BLOCH
I
T HAS BEEN estimated that between 40% and 80% of all cancer patients develop some degree of clinical malnutrition during their illness. 1,2 Patients with advanced cancer often suffer from protein-calorie depletion. The clinical effects of poor nutrition are manifested in poor wound healing, poor skin turgot leading to skin breakdown, and decubiti. Anastomotic leaks and wound dehiscence, along with electrolyte and fluid imbalances, endocrine abnormalities, and compromised immune function are common and can result in increased morbidity and mortality_3 Maintenance of optimal nutritional status is essential to avoid substantial nutrient deficits, weight loss, and the accompanying clinical consequences that can adversely affect outcome. A patient's nutritional status is affected by tumor type, stage of disease, and antineoplastic therapy. 4 Over the past two decades greater attention has been focused on strategies to manage the malnutrition that frequently accompanies a cancer diagnosis. As a result of increased knowledge and experience, snbstrates used to provide nutrition support have been greatly improved and expanded. In addition, technologic advances have contributed to new and varied delivery systems, simplifying the administration of many of these therapies .5 This article reviews options for providing adequate nutrition support for cancer patients. Three areas will be highlighted: the goals of nutrition support in the cancer patient; oral, enteral, and parenteral approaches to nutritional support; and pharmacologic influences on nutritional status, including the use of orexigenic agents to stimulate appetite and support nutrition in this population. NUTRITION SUPPORT IN THE CANCER PATIENT he determination of a given patient's nutritional needs begins with a comprehensive assessment of the factors contributing to T their specific clinical situation. Nutritional screening, the first step in this process, is necessary to determine nutritional risk and
NUTRITION SUPPORT INTERVENTIONS IN CANCER
facilitate identification of deficits early in the course of t r e a t m e n t . The result of this process is the categorization of patients into low-, moderate-, or high-risk groups. Screening tools should be oneology-specifie and have established validity and reliability for use in the c a n c e r population. Several examples of such i n s t r u m e n t s have been described in the literature_ 6s Weight is one of the m a j o r variables used to d e t e r m i n e nutritional risk. Significant weight loss (>10%) m a y be p r e s e n t in ->45% of all adult hospitalized c a n c e r patients. 9 The c o n s e q u e n c e s of significant weight loss and malnutrition have been well documented. 3,1°-12
Goals and Benefits of Nutrition Support The goals of nutritional interventions in the c a n c e r patient are to support anabolism and body composition, functional status, and quality of life. 13 A proactive a p p r o a c h to nutritional care is essential in ensuring that these goals are achieved. Historically, clinicians have viewed nutritional issues as low on the list of priorities. This perception leads to a reactive/repletion mode, which is often futile. Nutrition interventions m u s t be instituted early to be successful. Providing nutrition support is associated with a n u m b e r of benefits. Increases in weight, anthropometric m e a s u r e m e n t s , and s e r u m a l b u m e n have all been d o c u m e n t e d as a result of nutrition support interventions, as have i m p r o v e m e n t s in nitrogen balance and i m m u n e function. 14
Support Via the Oral Route The patient diagnosed with c a n c e r needs to m a k e every effort to sustain nutritional a d e q u a c y and m e e t caloric and nutrient r e q u i r e m e n t s via the oral route. Appetite m a y wane, pain m a y interfere with eating, or the disease process m a y affect the patient's ability to c o n s u m e adequate calories to m e e t nutritional requirements. In such cases, modification in caloric density, volume of food at each feeding, and s u p p l e m e n t s to a u g m e n t total intake m a y be required. Separation of fluids and solids m a y p r e v e n t early satiety or d u m p i n g s y m p t o m s . Pain, nausea, and other s y m p t o m s that have the potential to interfere with nutritional intake should be aggressively managed. An issue that is frequently raised by patients or family m e m b e r s is that of dietary restrictions. Patient a d h e r e n c e to restrictions m a y decrease the caloric intake that is so essential. No specific guidelines for caloric or dietary restrictions exist
123
for this population. In m o s t cases, dietary restrictions can be eliminated. C o n c e r n about cholesterol, fats, and artificial colors and flavors should not affect the c a n c e r patient's decision to select foods or products that might assist in meeting caloric and nutritional goals. Patients often refuse to use nutritional s u p p l e m e n t s that would augm e n t an inadequate caloric intake for fear of the artificial ingredients found in the product. Appropriate patient education is w a r r a n t e d in helping patients u n d e r s t a n d these issues. W h e n food c o n s u m p t i o n b e c o m e s inadequate, oral intake m a y need to be s u p p l e m e n t e d to m e e t caloric requirements. Two a p p r o a c h e s to nutrition s u p p l e m e n t a t i o n should be considered at this juncture: the enteral and p a r e n t e r a l routes of administration.
The Enterai Approach Alternative nutrition support via the enteral route should be p u r s u e d if adequate calories e a n n o t be c o n s u m e d by mouth. A variety of physiologic benefits are associated with the continued stimulation of the gut that occurs w h e n the enteral a p p r o a c h is used. Enteral nutrition prevents a t r o p h y of the mierovilli lining the intestinal wall, which can occur within a few days of diminished oral intake; this leads to changes in intestinal flora and histology, predisposing the patient to additional complications. Enteral tube placement. Most nutrient absorption occurs in the first third of the j e j u n u m , making p l a c e m e n t of the feeding tube in the s t o m a c h physiologically advantageous. This app r o a c h allows gastric secretions, bile acid, and p a n c r e a t i c e n z y m e s to mix with the bolus of food or formula as it passes from the s t o m a c h into the d u o d e n u m and jejunum. W h e n a patient's limitation in oral intake is projected to be of short duration, nasoenteric tube p l a c e m e n t m a y be the preferred m e t h o d of enteral access. Although this a p p r o a c h is c o n v e n i e n t and relatively simple, patients m a y be u n c o m f o r t a b l e with a p p e a r e n c e and the process of tube placement. In clinical situations in which the limitation in oral intake is e x p e c t e d to persist for m o r e than several weeks, an e n t e r o s t o m y is r e c o m m e n d e d . 15 Percutaneous, endoseopically placed g a s t r o s t o m y (PEG) or j e j u n o s t o m y feeding tubes are excellent options for long-term enteral support. The PEG feeding tube is especially effective for patients with m e c h a n i c a l or physical limitations of the head,
124
ABBY BLOCH
neck, or esophagus. In addition, those who experience anorexia, early satiety, or queasiness can also benefit substantially by using the PEG feeding tube to supplement oral intake. 16 Pereutaneous, endoseopically placed gastrostomy tube placement can be readily accomplished in the outpatient setting. Initially, a 24- to 28-French, 8- to 14-inch catheter will be inserted. After several weeks, this is replaced with a skin-level, low-profile feeding device. These flat devices, also known as buttons, allow the individual to resume a more normal lifestyle. Patients can wear tight-fitting clothes again, take showers, feel more comfortable with sexual activity, and have a more positive self-image. The jejunum may be used as an alternate location for feeding tube insertion when placement in the stomach is contraindicated. Jejunostomies are placed using endoscopic techniques similar to those used with PEG feeding tube insertions. 17 Nutritional support through jejunostomy tubes accesses the small bowel directly, bypassing exposure to gastric secretion and enzymes. Feeding contents and procedures need to be adjusted based on individual patient need. Once a PEG or jejunostomy feeding tube is in place, patients can continue to consume foods by the oral route for enjoyment purposes or social interaction. This knowledge often provides a level of comfort and a sense of normality for both patients and family members_
Administration strategies for enteral feedings. Several options for administering enteral formulas are available; the most common approaches are intermittent bolus and continuous feedings. If the gastrointestinal tract is intact, bolus feedings are the most appropriate approach, is Bolus feedings are easy to manage, require little equipment, and are relatively inexpensive. Flexibility in feeding schedules and ease in administration contribute to the appeal of this method. The timing of bolus feeding, for example, can mimic the routine of regular meals, which may provide a psychological benefit for patients. Patients should be instructed, however, that bolus meals should be consumed slower than regular meals to ensure maximum digestibility and absorption_ If the gastrointestinal tract is physiologically unable to tolerate bolus feedings or if the patient prefers to feed at night while sleeping, intermittent gravity or pump-assisted continuous slow-infusion
approaches are available. These methods require additional equipment and closer monitoring than bolus feedings. Gravity feedings must be adjusted to allow the formula to flow at a rate that is tolerated by the patient. Pump-assisted feedings require training of all involved in earing for the patient_ If members of the family are out of the home during the day, pumpzassisted feedings during the evening or at night might be easier to manage. Planning should include consideration of family members' schedules and commitments to ensure proper adherence to the feeding schedule. Enteral formula selection. Enteral formulas should be selected based on the following criteria: (1) gastrointestinal function; (2) physical characteristics of the formula, such as viscosity, osmolality, fiber content, and caloric density; (3) macronutrient content; (4) digestion, absorption, and utilization capability; (5) specific metabolic needs; (6) electrolyte and fluid requirements; and (7) financial concerns. Formulas are generally classified by macronutrient composition_ General purpose formulas, also called intact or polymeric formulas, contain biologically complete, intact protein such as easeinate, laetalbumin, beef, and soy protein. These formulas are well-tolerated by most patients. If a higher protein content or caloric density greater than 1 kcal/mL is desired, or if lactose-intolerance, volume limitations, or gastric discomfort exists, appropriate modifications or adjustments may be made based on clinical status and tolerance. Patients who are unable to digest or absorb intact protein may be given peptide fragments (dipeptides, tripeptides, or oligopeptides) and amino acids derived from hydrolysis of casein, whey, lactalbumin, or soy; these are also known as monomeric formulas. Such predigested monomeric formulas are indicated when a metabolic abnormality or clinical condition such as shortbowel syndrome exists. Moreover, disease-specific formulas are commercially available for patients who have renal, hepatic, and cardiopulmonary disease, metabolic stress, immunosuppression, or glucose intolerance. New formulas are being developed based on evolving nutrition research. 19The type and amount of fats added to enteral products are being modified. Antioxidants and micronutrients are being included to enhance formulas. As genetic research unfolds and metabolic characteristics of
NUTRITION
m a n y types of cells are revealed, specially formulated n u t r i e n t substrates will b e c o m e available_ s For the present, formula selection should be d e t e r m i n e d on an individualized basis. Since this process is complex, enlisting the aid of a trained dietary specialist is r e c o m m e n d e d . In the c a n c e r population, the need to obtain adequate calories is paramount_ Protein needs and other nutrients are important, but calorie requirem e n t s m u s t be m e t before the c a n c e r patient will show a weight response to nutrition support. Even w h e n appropriate enteral formulas are prescribed, the patient m a y not actually c o n s u m e enough to ensure weight m a i n t e n a n c e or gain. If this deficiency is not detected quickly, the patient can b e c o m e malnourished_ Clinieians need to evaluate actual daily intake and patient weight in a routine a n d systematic m a n n e r and m a k e changes as needed to ensure the success of the nutrition care plan.
The Parenterai Approach When the clinical situation precludes use of the gastrointestinal tract for feeding, total parenteral nutrition (TPN) should be considered. -'° Data on the use of TPN in eaneer are inconsistent21-e-~ Klein et a124 reviewed 28 prospective controlled trials evaluating the use of TPN in c a n c e r patients. These authors pooled data across studies a n d concluded that TPN m a y be useful in certain subsets of o n t o l o g y patients treated surgieally_ In patients treated with c h e m o t h e r a p y , however, no significant benefit in terms of survival, t r e a t m e n t tolerance, t r e a t m e n t toxicity, or t u m o r response was appreciated. In addition, an increased risk of developing infection was demonstrated. More recently, McGeer et al, 25 u n d e r the auspices of the A m e r i c a n College of Physicians, c o n d u c t e d a review of published TPN trials using recta-analytic techniques. When data from all trials were compiled, patients who had received c h e m o t h e r a p y and TPN versus c h e m o t h e r a p y alone d e m o n s t r a t e d an odds ratio of 0.81, ie, the survival of this group was only 81% as long as patients who received no TPN. In contrast, there have b e e n some studies in which advantages of TPN in specific populations have b e e n demonstrated. In one study, perioperativc TPN increased body weight, s e r u m proteins, i m m u n e function, and nitrogen balance. However, reduced postoperative complications or mortality were not seen. 2~ Based on a lack of consensus in the literature, it
SUPPORT INTERVENTIONS
IN CANCER
125
s e e m s that the routine use of TPN in t h e c a n c e r population is not justified_ 22 This modality should be used after careful consideration of an individual patient's risk and benefit. Table I provides a list of clinical situations in which it would be appropriate to use TPN_ W h e n used, p a r e n t e r a l formulas should contain adequate a m o u n t s of h y p e r t o n i c glueose, protein, fat emulsion, vitamins, electrolytes, and minerals to m e e t individualized patient nutritional needs. If not contraindicated, oral intake should be encouraged in conjunction with TPN for gut stimulation.
PHARMACOLOGIC ISSUES A
discussion of nutrition support in the c a n c e r patient would be i n c o m p l e t e without attention to pharmaeologie considerations. Medications frequently used in the c a n c e r population have the potential to alter nutritional parameters. Malabsorption m a y result from antineoplasties or other pharmacologic agents (Table 2). 27 I m p a i r e d digestion and absorption s e c o n d a r y to the use of these agents should not be overlooked as a possible cause of c o m p r o m i s e d nutritional status. Clinicians should b e c o m e familiar with m e t a bolic alterations associated with new agents. Moreover, when drugs are used in c o m b i n a t i o n protocols, the synergistic effects of these agents should to be considered.
Orexigenic Agents A n u m b e r of agents have been evaluated for their ability to increase the appetite in c a n c e r patients.2S 51 Investigations of eorticosteroids have d e m o n s t r a t e d limited effects on food intake, well-being, and p e r f o r m a n c e status. These agents m a y improve appetite indirectly by decreasing nausea and asthenia and improving pain control. However, the side effect profile of eortieosteroids TABLE
1.
Indications for the Use of Parenteral Support Severe malnutrition not corrected by enteral support Chronic malabsorption, severe diarrhea Short-bowel obstruction
High-output fistula Short-bowel secondary to bypass surgery Radiation enteritis Anticancer therapy will be compromised if malnutrition interferes with treatment schedule
126
ABBY BLOCH
i:ii:::Agents Commorliy P r e ~ r ~
:::::::Drug
.......
In the Cancer
..... : Nutritional Alteration :: : ........
.
.
.
.
.
.
.
Hyperglycem a hemorrhagic pan~ ::: :: : : : : . . . . creatitis . . . . . . : : ........ Chlorot#.an~sene Hyerca~emia:;: ......: : : ::::: Ci~i~tin ..... Hypeparfcemia, t!ypornagnesem~a :: Corti~steroids :: Sodium retention; potassium ~cal:::i ::: cium, magnesium and z i n c : excretion; hyperglycemia i: Diethylstilbestrol Hypercalcemia : Methotrexate :Folate and ca!cium :deflc~n ~ : Mithrarnycin Hypocalcem a, hypokalemia Sireptozocin .............. Sudden hypoglycemia ......... Tamoxifen Hypercalcemia :: Paclitaxef .... Nauseal vomiting, mucositis Treti~!n =Iall.trans Hypertdglycer~demia, elevated re~3noic acid) .... liver function tests VinCiistine Inappropriate ant d uret c hop mone secretion, hyponatremia, water retention, decreased serum osmolality, increased urine osmolality .....
some positive results, 29 but no substantial benefits were reported in any of the larger controlled trials investigating this agent. 33-35 The cannabinods, dronabinol and nabilone, have been tested in several populations. Two open studies 36,37 resulted in improvements in mood and appetite, but no significant effect on body weight gain was observed_ Additional trials are needed to determine how these agents should be used in the cancer population. Megestrol acetate, a progestational agent, has shown promise in several trials in which it was studied. Megesterol has demonstrated a doserelated benefit on appetite, caloric intake, bodyweight gain (primarily fat) 38,39 and sensation of well-being with an optimal dose of 800 mg/d administered orally. 4° Drugs to increase muscle mass, such as oxandrolone, growth hormones, and medroxyprogesterone acetate, are also becoming popular. Newer agents being studied are melatonin, thalidomide, omega-3 fatty acids, ~2-adrenoceptor agonists, synthetic analogs of anabolic-androgenic steroids, and anticytokine therapies. 29,41
CONCLUSION
and their potential to exacerbate muscle deterioration secondary to urinary protein losses preclude routine use of these agents. 29 Cyproheptadine, an antihistamine, has been used in Europe as an appetite stimulant. A controlled trial conducted in the United States, however, failed to demonstrate improvements in body weight or improved nutritional status in the patients who took it. 32 Hydrazine sulfate has been used as an inhibitor of gluconeogenesis. Smaller trials have shown
lterations in nutritional status are an integral part of the disease process of cancer. 42 Nutrition plays a significant role throughout the clinical course of this process. Clinicians have many options for providing adequate nutrition to the patient at risk for becoming malnourished. They must be encouraged to take advantage of these options by intervening early and aggressively to meet the nutritional needs of patients who struggle with their meals and food intake.
A
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NUTRITION SUPPORT INTERVENTIONS IN CANCER
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28. Herrington AM, Herrington JD, Church CA: Pharmacologic options for the treatment of eaehexia. Nutr Clin Pract 12:101-113, 1997 29. Gagnon B, Bruera E: A review of the drug treatment of cachexia associated with eaneer. Drugs 55:675-688, 1998 30. Ottery FD, Walsh D, Strawford A: Pharmacologic management of anorexia/cachexia. Semin Oncol 25:35-44, 1998 (suppl 6) 31. ttaslett PA: Anticytokine approaches to the treatment of anorexia and eachexia. Semin Oncol 25:53-57, 1998 (suppl 6) 32. Kardinal CG, Loprinzi CL, Schaid DJ, et al: A controlled trial of eyproheptadine in cancer patients with anorexia and/or eachexia. Cancer 65:2657-2662, 1990 33. Loprinzi CL, Juross SA, O'Fallon JV, et al: Randomized, placebo-controlled evaluation of hydrazine sulfate in patients with advanced colorectal cancer. J Clin Oneol 12:1121-1125, 1994 34. Loprinzi CL, Goldberg RM, Su JQ: Placebo-controlled trial of hydrazine sulfate in patients with newly diagnosed non-small-eell lung cancer. J Clin Onco112:1126-1129, 1994 35 Kosty MP, Fleishman SB, Herndon JE, et al: Cisplatin, vinblastine and hydrazine sulfate in advanced non-small-cell lung cancer: A randomized placebo-controlled, double-blind phase III study of the cancer and leukemia group B. J Clin Oncol 12:1113-1120, 1994 36. Wadleigh R, Spaulding M, Lembersky B, et al: Dronabinol enhancement of appetite in cancer patients. Proe Am Soe Clin Oncol 9:331, 1990 (abstr) 37. Nelson K, Walsh D, Deeter P, et al: A phase II study of delta-nine-tetrahydroeannabinol for appetite sumulation in cancer associated anorexia. J Palliat Care 10:14-18, 1994 38. Loprinzi CL, Sehaid DJ, Dose AM, ct al: Bodycomposition changes in patients who gain weight while receiving megestrol acetate. J Clin Oneol 11:152-154, 1993 39. Oster MH, Enders SR, Samuels SJ, et al: Megestrol acetate m patients with AIDS and caehexia. Ann Intern Med 121:400-408, 1994 40. Loprinzi CL, Miehalak JC, Sehaid DJ: Phase three evaluation of four doses of megestrol acetate as therapy for patients with cancer anorexia and/or caehexia. J Clin Oncol 11:762-767, 1993 41. Nash TM: Use of anabolic agents in patients with cancer caehexia. Support lane 21:14-18, 1999 42. Heber D, Blackburn GL, Go VLW: Introduction: The principles of nutritional oncology, in Heber D, Blackburn GL, Go VLW (eds): Nutritional Oneology. San Diego, CA, Academic, 1999. pp 1-10