Is a lymph node dissection required for gastric Gastrointestinal Stromal Tumor (GIST)?

Lymph Node Dissection for Gastric GIST

Prophylactic lymph node dissection is not necessary for gastric gastrointestinal stromal tumors (GISTs), except in cases of SDH-mutated GISTs where pickup dissection of swollen lymph nodes may be indicated. 1

Rationale for Omitting Lymph Node Dissection in Gastric GIST

• Lymph node metastasis is very rare in GISTs, unlike in other gastric malignancies 1
• Standard surgical approach for GISTs focuses on complete resection with negative margins without routine lymph node dissection 1
• The natural spread pattern of GISTs differs from gastric adenocarcinoma, with hematogenous spread and peritoneal seeding being more common than lymphatic spread 1

Surgical Approach for Gastric GIST

• The primary goal of surgery is complete resection (R0) with negative margins and functional preservation when possible 1
• Wedge resection of the stomach is typically adequate for gastric GISTs 1
• Surgical principles include:
  • Avoiding tumor rupture and injuries to the pseudocapsule 1
  • Achieving macroscopic and microscopic negative margins 1
  • No prophylactic lymph node dissection 1

Exception: SDH-Mutated GISTs

• SDH-mutated GISTs represent a distinct subset with different biological behavior 1
• For these specific tumors, pickup dissection of visibly enlarged lymph nodes may be indicated 1
• This is the only GIST subtype where lymph node assessment should be considered 1

Laparoscopic vs. Open Approach

• Laparoscopic surgery is appropriate for small gastric GISTs (generally <5 cm) 1
• When using laparoscopic approach:
  • Direct handling of tumors with forceps is contraindicated 1
  • A plastic bag should be used during removal to minimize risk of tumor seeding 1
  • The same oncological principles apply as in open surgery 1

Risk Assessment and Follow-up Considerations

• Risk classification for recurrence is based on tumor size, mitotic index, tumor location, and rupture status 1
• For high-risk GISTs, adjuvant imatinib therapy for 3 years is the standard treatment 1
• Follow-up should focus on the liver and peritoneum, which are the most common sites of recurrence, rather than lymph nodes 1

Clinical Implications

• Avoiding unnecessary lymph node dissection in gastric GIST:
  • Reduces surgical morbidity 1
  • Preserves gastric function 1
  • Aligns with the biological behavior of the disease 1
• Multidisciplinary treatment planning involving pathologists, radiologists, surgeons, and medical oncologists is recommended for optimal management 1