What is the treatment approach for a patient with carcinoma (cancer) of the stomach antrum?

Treatment Approach for Gastric Antrum Carcinoma

Surgical resection with perioperative chemotherapy is the standard curative treatment for resectable gastric antrum carcinoma, with the specific approach determined by tumor stage after comprehensive multidisciplinary evaluation. 1, 2

Initial Diagnostic Workup and Staging

Before any treatment decision, complete staging is mandatory and includes:

• Endoscopy with biopsy to confirm adenocarcinoma histology, determine Lauren classification (intestinal vs. diffuse type), and obtain tissue for HER2 testing if metastatic disease is suspected 1, 2
• Contrast-enhanced CT of thorax, abdomen, and pelvis to detect lymphadenopathy, metastatic disease, and assess resectability 1, 2
• Laparoscopy with peritoneal washings for all stage IB-III cancers to exclude occult peritoneal metastases not visible on imaging 1, 3
• Blood tests including complete blood count (to assess for iron-deficiency anemia), liver and renal function tests 1, 2

Important caveat: Endoscopic ultrasound (EUS) is less useful specifically for antral tumors compared to other gastric locations, so do not rely on it heavily for T-staging in this anatomic site 1

Multidisciplinary Treatment Planning

All treatment decisions must be made by a multidisciplinary team including surgeons, medical oncologists, radiation oncologists, gastroenterologists, radiologists, pathologists, dieticians, and nurse specialists before proceeding 1, 2, 4

Stage-Specific Treatment Algorithm

Very Early Disease (T1a)

Endoscopic resection alone is appropriate ONLY if ALL of the following criteria are met 1, 2, 3:

• Confined to mucosa (T1a)
• Well-differentiated histology
• Non-ulcerated
• ≤2 cm in diameter
• No lymphovascular invasion

If any criterion is not met, proceed to surgical resection.

Localized Resectable Disease (Stage IB and Above)

Perioperative chemotherapy followed by surgery followed by completion of chemotherapy is the standard of care 1, 2, 4:

• Preoperative chemotherapy: 3 cycles of ECF (epirubicin 50 mg/m², cisplatin 60 mg/m², continuous infusion 5-FU 200 mg/m²/day) or ECX (substituting capecitabine for 5-FU) 1
• Surgery: Distal gastrectomy with D2 lymphadenectomy (minimum 14 lymph nodes examined, optimally ≥25 nodes) 1, 4, 3
• Postoperative chemotherapy: Complete remaining 3 cycles of the same regimen 1

This perioperative approach improved 5-year survival from 23% to 36.3% in the landmark MAGIC trial 1, 4

Alternative approach (primarily used in North America): Surgery first followed by postoperative chemoradiation (45 Gy in 25 fractions with concurrent 5-FU/leucovorin) if perioperative chemotherapy was not given 1, 4. However, this approach is less accepted in Europe due to toxicity concerns and the fact that 54% of patients in the pivotal trial received suboptimal surgery (less than D1 dissection) 1.

For patients who undergo surgery without preoperative chemotherapy: Adjuvant chemotherapy with a fluoropyrimidine-based doublet for 6 months is recommended 2

Surgical Principles for Antral Tumors

• Distal gastrectomy is the appropriate operation for antral location 4, 3
• D2 lymphadenectomy is mandatory, removing perigastric nodes and nodes along celiac arterial branches 3, 5
• Resection margins: Achieve ≥3 cm margins for Borrmann I-II tumors and ≥5 cm for Borrmann III-IV tumors 3
• Splenectomy should NOT be performed unless the tumor directly invades the spleen, as it increases complications without survival benefit 3

Locally Advanced Unresectable Disease

Concurrent chemoradiation is recommended for good performance status patients with unresectable locally advanced disease 3:

• Chemotherapy options include capecitabine + paclitaxel, cisplatin + fluoropyrimidine, or oxaliplatin + fluoropyrimidine given concurrently with radiation 3
• Re-evaluate for surgical resectability after treatment response 3

Metastatic Disease (Stage IV)

Palliative combination chemotherapy should be offered to patients with good performance status 1, 2:

• First-line regimen: Docetaxel 75 mg/m² + cisplatin 75 mg/m² + fluorouracil 750 mg/m²/day × 5 days, repeated every 3 weeks 6
• Alternative first-line: ECF or ECX regimen (epirubicin, cisplatin/oxaliplatin, fluoropyrimidine) 1
• HER2-positive tumors: Add trastuzumab to first-line platinum/fluoropyrimidine doublet 5
• Second-line: Ramucirumab (anti-angiogenic) with paclitaxel 5
• Third-line: Nivolumab or pembrolizumab (anti-PD-1 immunotherapy) 5

Median survival with palliative chemotherapy is less than 1 year 5

Critical Pitfalls to Avoid

• Do not proceed to surgery without laparoscopy in potentially resectable stage IB-III disease, as imaging misses peritoneal metastases in a significant proportion of patients 1, 3
• Do not accept inadequate lymph node evaluation (fewer than 14 nodes examined), as this leads to understaging and suboptimal treatment planning 1, 4, 3
• Do not perform routine splenectomy, as it increases morbidity without oncologic benefit 3
• Do not use intensive surveillance protocols after curative treatment, as there is no evidence that routine follow-up improves outcomes; symptom-driven visits are recommended instead 1, 2
• Do not forget HER2 testing in metastatic disease, as HER2-positive patients benefit from targeted therapy 2, 5

Follow-Up After Curative Treatment

Symptom-driven visits are recommended rather than intensive routine surveillance, as regular intensive follow-up does not improve outcomes 1, 2. Perform history, physical examination, and blood tests only when symptoms suggest recurrence, and consider imaging for patients who are candidates for palliative chemotherapy 1, 4.