Initial Treatment for Gastric Adenocarcinoma

Diagnostic Workup and Staging

• The National Comprehensive Cancer Network recommends a complete physical examination, blood counts, liver and renal function tests for patients with gastric adenocarcinoma 3, 4
• A contrast-enhanced CT scan of thorax and abdomen (± pelvis) is recommended for initial staging of gastric adenocarcinoma 3, 4
• Endoscopy with biopsy is necessary for histological confirmation of gastric adenocarcinoma 3, 4
• Endoscopic ultrasound (EUS) is helpful in determining T and N stages, especially in early disease 3, 5
• Laparoscopy ± peritoneal washings is recommended for all stage IB-III stomach cancers to detect occult metastatic disease 3, 2
• PET imaging may improve staging through increased detection of involved lymph nodes/metastatic disease 3

Treatment Algorithm Based on Disease Stage

• The European Society for Medical Oncology recommends perioperative chemotherapy with ECF (epirubicin, cisplatin, and 5-FU) for stage IB or higher disease 1, 2
• The National Comprehensive Cancer Network recommends surgical resection with adequate margins (typically 4 cm from gross tumor) for localized disease 2, 6
• Gastric resection should include regional lymphatics with D2 lymphadenectomy (perigastric lymph nodes and those along named vessels of the celiac axis) 2, 7
• At least 15-16 lymph nodes should be examined for adequate staging 2
• For locally advanced disease (≥Stage IB), perioperative chemotherapy with ECF is recommended (category 1) 1, 2
• The American Society of Clinical Oncology recommends palliative chemotherapy for metastatic disease (Stage IV) 1, 7
• Standard regimens for palliative chemotherapy include DCF (docetaxel, cisplatin, and 5-FU) and ECF (epirubicin, cisplatin, and 5-FU) 2
• For HER2-positive tumors, trastuzumab in combination with chemotherapy is recommended 2, 7

Special Considerations

• The European Society for Medical Oncology recommends multi-disciplinary treatment planning, involving surgeons, medical and radiation oncologists, gastroenterologists, radiologists, and pathologists 3, 4
• Recent advances in molecular profiling have led to more personalized treatment approaches, with HER2 status assessment now standard for all gastric adenocarcinomas to determine eligibility for targeted therapy 4

Common Pitfalls to Avoid

• Diagnostic laparoscopy is crucial to detect occult peritoneal metastases not visible on CT 3, 5