Malnutrition is a dietary deficiency that results from various environmental and medical conditions, such as mental health problems, social problems, GI disorders, and alcoholism among others. This is defined as weight loss greater than 5% to 10% of ideal body weight, with preferential loss of adipose tissue over muscle. The resting energy expenditure is reduced. Improved caloric intake of nutritious food or nutritional supplements will often reverse malnutrition and starvation. Malnutrition can occur in specific scenarios; however, cachexia is a pathology commonly observed in patients with head and neck cancer. Cachexia is a multifactorial metabolic syndrome characterized by systemic sarcopenia, with or without loss of fat mass that accompanies a chronic disease (usually malignant), whereas malnutrition is a lack of adequate nourishment. While all cachectic patients suffer from malnutrition, cachexia is not always present in malnourished patients. Loss of adipose tissue in cachexia is a result of increased lipolysis by tumor or host products. Sarcopenia is mainly due to diminished synthesis of muscle protein and increased degradation of proteins; these amino acids are shunted into acute phase response proteins in the liver resulting in liver hypertrophy.
Patients may experience either early satiety or food aversion.
In addition, there could be other physical factors contributing to patients losing appetite in cachexia. They are as follows:
Dysphagia or odynophagia
Anorexia, fatigue, mouth ulcers, nausea, and gastrointestinal disturbance.
Cachexia is diagnosed as weight loss of more than 5% over past 6 months or a body mass index (BMI) of less than 20 kg/m2. Although no single marker can comprehensively measure the nutritional status, albumin, pre-albumin, and transferrin to assess nutritional status.
The importance of diagnosing and treating both malnutrition and cancer cachexia is evident in the increased perioperative morbidity when untreated. Poor wound healing, increased rates of sepsis, and increased rates of wound infections are seen with malnutrition. Increased complications from surgery, radiation, and chemotherapy are seen in patients with cancer cachexia. There is mounting evidence that cancer cachexia profoundly affects cardiac structure and function, causing significant impairment in patients who previously had no history of cardiac dysfunction. The implications of this for patients undergoing major surgical ablation may be profound, especially in the perioperative period. During therapy, weight loss is an independent poor prognostic sign. Morbidly obese patients can still be profoundly malnourished and weight loss during treatment is not necessarily healthy for them. This form of sarcopenic obesity may be difficult to diagnose and treat.
Nutritional assessment and counseling by a certified nutritionist is a critical part of the evaluation of patients with head and neck cancer. Additionally, early intervention by a speech pathologist is an integral part of many multidisciplinary oncology pathways for head and neck cancer and is important to determine if oral nutrition will be sufficient, or if alternative means will be necessary.
Document weight loss in the past 3 to 6 months
Unintentional—consider cancer cachexia
Dysphagia or odynophagia
Loss of muscle mass, especially Type II fast twitch muscles such as biceps or quadriceps
Temporal muscle fat pad loss, orbital fat loss
Evidence of vitamin deficiencies such as dry scaling skin, cheilosis, or stomatitis
BMI = weight (kg)/height (cm) × 100
Midarm circumference can be used to estimate skeletal muscle mass.
Levels less than 3.0 g/dL are associated with perioperative morbidity.
Low in malnutrition, infection, burns, fluid overload, hepatic failure, cancer, nephrotic syndrome.
Transferrin (200-360 mg/dL).
Levels less than 150 mg/dL indicates malnutrition.
More accurately reflects short-term changes in protein nutritional status.
It may be calculated from the total iron-binding capacity (TIBC). Transferrin = (0.68 × TIBC) + 21.
Affected by iron status.
Prealbumin (16-40 mg/dL).
2 to 3 days’ half-life.
Can be used to assess nutritional status and the need for supplementation.
Low in malnutrition, infection, liver failure; increase in renal failure.
C-reactive protein (CRP).
Elevated CRP helps determine if above proteins are reduced because of inflammatory process versus inadequate substrate.
More than 10 suggests physiological stress.
May affect reliability of albumin and prealbumin as nutrition status surrogates.
Anemia is associated with cancer cachexia.
Serum glucose levels may help detect insulin resistance seen in patients with cancer cachexia.
A total lymphocyte count (TLC) of less than 1700/µL is a gross measurement of impaired humoral immunity and is associated with a fivefold increase in the risk of wound infection.
The prognostic nutritional index (PNI) is predictive of complications and morbidity.
In general, physical examination is a better tool for diagnosing malnutrition; however, overall assessment must be analyzed between physical findings and serum markers. There are subjective global assessment tools that are fairly simple. Inexpensive questionnaires combine data from weight and dietary histories with physical examination observations to subjectively classify patients as well nourished, moderately malnourished, or severely malnourished.
Unintentional weight loss may be due to a paraneoplastic syndrome, cancer cachexia. Anemia, hypoglycemia, and elevated CRP are hallmarks of this wasting syndrome. It is not treatable with nutritional supplementation alone, although this is an integral part of the therapy. There are no FDA-approved remedies for cancer cachexia, but current management strategies include corticosteroids and megesterol acetate (Megace). Future strategies may include nutraceuticals, omega-3 fatty acids in nutritional supplements, and targeted treatments using Ghrelin analogs. There is preliminary data that nonsteroidal anti-inflammatory drugs may be useful in dampening the inflammatory response that is associated with this. A nutritional consult is a critical part of evaluating patients. If patients are malnourished, nutritional supplements should be considered part of the treatment plan.
Patients who have had negligible nutrient intake for 5 days may be at risk for refeeding syndrome, which occurs within 4 to 7 days of starting refeed. Profound electrolyte imbalances may occur, especially hypophosphatemia, which may be accompanied by cardiac arrhythmias (most common cause of death), coma, confusion, and convulsions. During fasting, the main sources of energy are ketone bodies derived from fatty acids and amino acids. When the patient undergoes refeeding, augmented insulin secretion results in increased glycogen, fat, and protein synthesis that diminishes already dangerously low phosphate, potassium, and magnesium serum levels.
Glucose and thiamine levels often drop. The shifting of electrolytes and fluid balance increases cardiac workload. Increased oxygen consumption and inadequate oxygen delivery strains the respiratory system. These patients merit close monitoring. Replenishing vital electrolytes (potassium, phosphate, and magnesium) in a controlled setting is essential.
For the malnourished patient, the physician must determine the nutrient and caloric requirements.
The average adult needs 30 to 35 kcal/kg/d.
To avoid protein-calorie malnutrition, provide 6.25 g of protein per 125 to 150 kcal.
Nitrogen balance should be assessed through serial laboratory and body weight assessments.
Nutritional Delivery Techniques
Oral nutrition is preferred when possible, but many head and neck disorders, particularly head and neck cancer and its surgical or nonsurgical treatment, may preclude adequate nutrition due to dysphagia, aspiration, and discomfort. The use of feeding tubes often helps bypass areas of severe mucositis in patients undergoing radiation or chemoradiation therapy, and may be used postoperatively after major head and neck surgery if oral feeding is not advisable due to acute dysphagia or reconstructive concerns.
Nasogastric (NG) tube
Advantage: easiest to place
Disadvantages: nasal and pharyngeal discomfort, esophageal reflux, risk of alar necrosis
Gastrostomy (G) tube (usually percutaneous endoscopic gastrostomy, PEG)
Advantages: well-tolerated, relative ease of placement
Disadvantages: surgical procedure required, possibility of infection or intra-abdominal complication
Jejunostomy (J) tube
Advantage: reduces gastroesophageal reflux and vomiting (important if complex reconstruction is present)
Disadvantages: does not allow for bolus feedings.
Prophylactic enteral nutrition must be analyzed independently per patient, taking into consideration tumor site and stage, the patient’s socio-economic status, and psychological characteristics. There is no consensus about weather prophylactic tube placement is appropriate, although this is commonly done in patients with more than 10% weight loss, severe pretreatment dehydration, aspiration and dysphagia, and in patients who will be receiving intense multimodality treatment to the upper aerodigestive tract (eg, concurrent chemoradiation). Prophylactic G-tube placement should be considered prior to initiation of radiation and chemoradiation, as interruption of treatment due to dehydration or malnourishment may lead to compromise in survival. Patients with feeding tubes have lower mean weight loss when compared to patients without feeding tubes.4 Although both NG and G tubes have specific advantages and disadvantages, both are effective in maintaining nutritional status. Nevertheless, when possible, oral feds should be preserved in properly selected patients to decrease the chances of late dysphagia, as patients who become dependent on enteral feeding during radiation are more likely to remain completely or partially dependent in the long term.