Initial Treatment for Gastric Adenocarcinoma
The initial treatment for gastric adenocarcinoma should be determined by disease stage, with surgical resection as the only potentially curative option for localized disease, and perioperative chemotherapy with ECF (epirubicin, cisplatin, and 5-FU) recommended for stage IB or higher disease. 1
Diagnostic Workup and Staging
Before initiating treatment, proper staging is essential to determine the appropriate therapeutic approach:
- Complete physical examination, blood counts, liver and renal function tests 1
- Contrast-enhanced CT scan of thorax and abdomen (± pelvis) for initial staging 1
- Endoscopy with biopsy for histological confirmation 1
- Endoscopic ultrasound (EUS) for determining T and N stages, especially helpful in early disease 1
- Laparoscopy ± peritoneal washings recommended for all stage IB-III stomach cancers to detect occult metastatic disease 1
- PET imaging may improve staging through increased detection of involved lymph nodes/metastatic disease 1
Treatment Algorithm Based on Disease Stage
Early Gastric Cancer (T1a)
- Endoscopic mucosal resection may be considered in experienced centers 1
- This approach is suitable for well-differentiated tumors ≤2 cm confined to the mucosa 1
Localized Disease (T1b-T3)
- Surgical resection with adequate margins (typically 4 cm from gross tumor) 1
- Options include distal gastrectomy, subtotal gastrectomy, or total gastrectomy depending on tumor location 1
- Gastric resection should include regional lymphatics with D2 lymphadenectomy (perigastric lymph nodes and those along named vessels of the celiac axis) 1
- At least 15-16 lymph nodes should be examined for adequate staging 1, 2
Locally Advanced Disease (≥Stage IB)
- Perioperative chemotherapy with ECF (epirubicin, cisplatin, and 5-FU) is recommended (category 1) 1
- Alternative approach: Surgery followed by adjuvant chemoradiotherapy with fluoropyrimidine (5-FU or capecitabine) 1
- The European MAGIC trial demonstrated improved progression-free and overall survival with perioperative chemotherapy compared to surgery alone 1
T4 Tumors
- Require en bloc resection of involved structures 1
- May benefit from neoadjuvant chemotherapy to downstage the tumor before surgical intervention 1
Metastatic Disease (Stage IV)
- Palliative chemotherapy is recommended 1
- Standard regimens include:
Special Considerations
- Multi-disciplinary treatment planning is mandatory, involving surgeons, medical and radiation oncologists, gastroenterologists, radiologists, and pathologists 1
- Patients should be referred to higher-volume centers with adequate support to manage potential complications 2
- Laparoscopic resections should be performed to the same standards as open resections by surgeons experienced in both advanced laparoscopic surgery and gastric cancer management 2
- For gastric adenocarcinoma, docetaxel in combination with cisplatin and fluorouracil is FDA-approved for patients who have not received prior chemotherapy for advanced disease 3
Common Pitfalls to Avoid
- Underestimating the extent of disease: Diagnostic laparoscopy is crucial to detect occult peritoneal metastases not visible on CT 1
- Inadequate lymphadenectomy: D2 lymphadenectomy is preferred over D1 for curative-intent resection 2
- Insufficient lymph node assessment: At least 16 lymph nodes should be examined for proper staging 2
- Performing palliative gastric resection in asymptomatic patients with metastatic disease: Surgery should be considered only for palliation of symptoms in the metastatic setting 2
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 1, 4.