What are the common types of stomach cancer in pediatric patients and their treatment approaches?

Types of Stomach Cancer in Pediatric Patients and Treatment Approaches

Pediatric gastric cancer is rare but requires prompt diagnosis and aggressive treatment, with surgical resection being the primary treatment modality for most types, followed by appropriate adjuvant therapy based on histological classification. 1

Common Types of Gastric Cancer in Pediatric Patients

Adenocarcinoma

• Represents approximately 5-10% of pediatric gastric cancers
• Two major histologic subtypes:
  • Intestinal type: Better prognosis, preceded by precancerous lesions
  • Diffuse type: More aggressive behavior, worse prognosis 2, 3
• Often presents at advanced stages with poor outcomes

Gastric Stromal Tumors (GIST)

• Most common gastric tumor in children (25-30% of pediatric gastric tumors)
• Pediatric GIST differs from adult GIST:
  • Often lacks KIT or PDGFRA mutations
  • More common in females
  • May occur as part of syndromes (Carney triad, Carney-Stratakis syndrome) 2, 4
• Better prognosis than adult GIST despite frequent metastasis

Lymphoma

• Represents 15-20% of pediatric gastric tumors
• Usually non-Hodgkin lymphoma, predominantly B-cell type
• May present with abdominal pain, vomiting, and weight loss 5, 6

Rare Types

• Teratomas (10-15%)
• Inflammatory myofibroblastic tumors (5-10%)
• Rhabdomyosarcoma (rare but aggressive)
• Hamartomas (benign) 5, 6

Clinical Presentation

• Common symptoms include:
  • Abdominal pain (most common)
  • Vomiting
  • Weight loss
  • Abdominal mass
  • Melena or anemia
  • Fever of undetermined origin 6, 3
• Risk factors:
  • H. pylori infection
  • Family history of gastrointestinal cancer
  • Obesity and obesity-related comorbidities
  • Tobacco exposure 3

Diagnostic Approach

1. Initial Evaluation:

   • Complete blood count (check for anemia)
   • Contrast-enhanced CT scan of thorax, abdomen, and pelvis 2, 1

2. Endoscopic Assessment:

   • Endoscopy with biopsy is essential for definitive diagnosis
   • Endoscopic ultrasound (EUS) for T and N staging 2, 1

3. Additional Staging:

   • Laparoscopy with peritoneal washings to exclude metastatic disease
   • PET-CT may improve staging through detection of involved lymph nodes/metastatic disease 2

Treatment Approaches

Surgical Management

• Primary treatment modality for most pediatric gastric tumors 1, 5
• Surgical approach based on tumor location:
  • Distal (antral) tumors: Subtotal gastrectomy
  • Proximal tumors: Total gastrectomy
  • Cardia/subcardia tumors: Extended total gastrectomy or esophagogastrectomy 2
• Lymphadenectomy extent:
  • D2 lymphadenectomy recommended for stage II and III cancers if patient is fit enough
  • Minimum 14 lymph nodes, optimally 25 lymph nodes should be harvested 2, 1

Endoscopic Resection

• Limited to early-stage tumors meeting specific criteria:
  • Well-differentiated tumors ≤2 cm
  • Confined to mucosa (T1a)
  • Non-ulcerated lesions 1
• Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) techniques

Adjuvant Therapy

• Chemotherapy:
  • Recommended for stage IB or higher
  • Common regimens include:
    • ECF (epirubicin, cisplatin, 5-fluorouracil)
    • ECX (epirubicin, cisplatin, capecitabine)
    • Cisplatin + fluoropyrimidine
    • Oxaliplatin + fluoropyrimidine 1
• Radiotherapy:
  • Concurrent chemoradiotherapy may be considered in selected cases
  • Can be used for pain management in advanced disease 1

Supportive Care

• Nutritional support is critical:
  • Feeding tubes as needed
  • Monitoring for vitamin B12, iron, and calcium deficiencies
• Management of obstruction:
  • Endoscopic stenting
  • Venting gastrostomy 1

Prognosis and Follow-up

• Prognosis varies significantly by tumor type:
  • Adenocarcinoma: Generally poor prognosis due to late diagnosis
  • GIST: Better prognosis than adult counterparts
  • Benign tumors: Excellent prognosis with complete resection 5, 6
• Regular follow-up is necessary to monitor:
  • Recurrence
  • Nutritional status
  • Treatment-related complications 1

Important Considerations

• Pediatric gastric tumors have distinct biologic and clinical features compared to adult tumors 4
• Multidisciplinary team approach is essential, involving pediatric surgeons, oncologists, gastroenterologists, radiologists, and pathologists 2, 1
• Complete surgical resection whenever feasible offers the best chance for cure 5, 6
• High index of suspicion is needed as symptoms may be vague and nonspecific 5