9.1 Pediatric Oncology & HSCT Nutrition

Malnutrition in Pediatric Cancer

Malnutrition is common in children with cancer, both at diagnosis and during therapy. Prevalence varies by tumor type: roughly 5–10% of children with standard-risk acute lymphoblastic leukemia (ALL) are undernourished at diagnosis, compared with up to 50% of those with advanced or metastatic solid tumors. Overnutrition matters too — obesity at diagnosis is increasingly common and is independently associated with worse outcomes and more toxicity in ALL.

Cancer cachexia must be distinguished from simple starvation. Starvation is a protein-sparing, hypometabolic adaptation that reverses fully when feeding resumes. Cachexia is a hypermetabolic, inflammatory state driven by tumor-derived cytokines such as tumor necrosis factor-alpha and interleukin-6, in which skeletal muscle is catabolized despite adequate intake, and feeding alone does not reverse it. Because corticosteroids can preserve or increase weight through fat and fluid gain while muscle is lost, weight alone is a poor assessment tool; serial mid-upper arm circumference or triceps skinfold measurements give a better picture of lean mass.

Risk Stratification for Nutrition Support

Treatment-Related Nutrition Problems

Mucositis from chemotherapy and radiation causes painful oral and esophageal ulceration. Management includes meticulous oral care (soft brushing, saline or bicarbonate rinses), topical analgesia before meals, and texture modification — soft, moist, bland foods served cool; avoid acidic, spicy, salty, and coarse foods.

Nausea and vomiting are far better controlled in the modern antiemetic era (5-HT3 antagonists, NK1 antagonists), but anticipatory nausea and learned food aversions persist. Practical counseling: avoid serving favorite foods on chemotherapy days (to prevent aversion conditioning), offer small frequent meals, and prefer cold or room-temperature foods, which emit less odor.

Taste changes (dysgeusia), including a metallic taste, reduce intake; plastic utensils and alternate protein sources (eggs, dairy, poultry instead of red meat) help.

Neutropenia historically triggered the restrictive 'neutropenic diet' (no fresh fruits or vegetables, no salad bars). Controlled studies have shown no infection benefit from these broad restrictions, and major pediatric oncology centers now emphasize food safety rather than food-group restriction: thorough hand hygiene, safe food handling and storage, well-cooked meats and eggs, pasteurized dairy only, and avoidance of raw sprouts, unpasteurized products, and deli meats unless reheated until steaming.

Steroids, Asparaginase, and Methotrexate

• Corticosteroids (prednisone, dexamethasone) in ALL induction cause hyperglycemia, intense appetite with rapid weight gain, myopathy, and bone loss. Counsel families on structured meals and planned snacks rather than unrestricted grazing.
• Asparaginase can cause pancreatitis — during and after an episode, prescribe a low-fat diet (with pancreatic rest if severe). Asparaginase also causes hypertriglyceridemia (usually transient; severe elevations managed with a low-fat diet and rarely insulin or fibrates), hyperglycemia, coagulopathy, and hepatotoxicity.
• Methotrexate is a folate antagonist that inhibits dihydrofolate reductase; after high-dose methotrexate, leucovorin (folinic acid) rescue protects normal cells. Know the concept that high-dose supplemental folate could theoretically blunt methotrexate's antileukemic effect — routine folate supplements are generally avoided during active methotrexate therapy.

Enteral and Parenteral Support

When oral intake cannot meet needs, nasogastric (NG) enteral feeding is accepted and safe, even during neutropenia and thrombocytopenia, and should be started early — before significant weight loss accrues — rather than as a last resort. A gastrostomy tube is considered when support will be prolonged (typically >3 months) and the child is stable enough for placement. Parenteral nutrition (PN) is reserved for a genuinely unusable gut: severe grade 3–4 mucositis with ileus, severe gut graft-versus-host disease (GVHD), or obstruction. Enteral feeding preserves gut integrity and carries a lower infection risk than PN.

HSCT-Specific Nutrition

Conditioning with high-dose chemotherapy with or without total body irradiation (TBI) makes mucositis nearly universal, and most allogeneic recipients require nutrition support. Acute gut GVHD presents with high-volume secretory diarrhea and cramping; management is stepwise: bowel rest with PN for severe disease, then gradual reintroduction of low-fiber, low-lactose, low-fat foods advanced as tolerated, with repletion of zinc and electrolytes lost in stool. Food safety precautions last for the duration of immunosuppression — often 6–12 months or longer if GVHD persists — not merely until neutrophil recovery. Vitamin D deficiency is common and should be monitored and supplemented. Important late effects include growth failure from growth hormone deficiency after TBI in young children and reduced bone mineral density; ensure adequate calcium, vitamin D, and weight-bearing activity.

Survivorship and Growth

Survivors of childhood cancer — especially ALL survivors treated with cranial irradiation and corticosteroids — carry elevated rates of obesity, insulin resistance, and metabolic syndrome. Long-term follow-up should include cardiometabolic screening and healthy-lifestyle counseling. Throughout active treatment, monitor weight, height, and BMI trajectory with the goals of preserving growth velocity, preventing undernutrition, and limiting excessive steroid-driven weight gain.