What is the optimal management strategy for gastric antrum carcinoma?

Optimal Management of Gastric Antrum Carcinoma

For gastric antrum malignancy, the management strategy is stage-dependent: perform surgical resection (subtotal or total gastrectomy with D2 lymph node dissection) for localized/locally advanced disease combined with perioperative chemotherapy and immunotherapy, while metastatic disease requires systemic therapy with biomarker-directed treatment selection.

Stage-Specific Treatment Algorithm

Localized Disease (Confined to Stomach)

For early-stage antral cancer:

• Endoscopic resection is appropriate only for select T1aN0 lesions with clear negative margins 1
• Surgical resection remains the cornerstone for most localized disease, with 75% 5-year survival when treated appropriately 2

For surgical approach:

• Subtotal gastrectomy is adequate for antral adenocarcinoma and shows equivalent survival to total gastrectomy (49.7% vs 45.6% 5-year survival) with shorter hospital stays 3
• D2 lymph node dissection is appropriate for curative intent cases, with assessment of ≥16 lymph nodes necessary for adequate staging 1
• Surgery should be performed by experienced surgeons (>6 resections/year) at high-volume centers (>15 resections/year) 1

Locally Advanced Disease

Perioperative chemotherapy with immunotherapy is now standard:

• Administer perioperative chemotherapy with 5-fluorouracil, oxaliplatin, and docetaxel (FLOT regimen) combined with immunotherapy (durvalumab) 2
• This approach can downstage tumors significantly, even converting initially unresectable disease to resectable status 4
• Multidisciplinary decision-making before treatment initiation is necessary 1

Preoperative staging requirements:

• CT abdomen/pelvis is necessary 1
• Diagnostic laparoscopy is appropriate before treatment to exclude peritoneal disease 1
• PET scans are not routinely indicated 1

Metastatic/Unresectable Disease

First-line therapy selection is biomarker-driven:

For PD-L1 positive tumors (CPS ≥5):

• Nivolumab plus chemotherapy (category 1 recommendation) provides 3 months additional survival versus chemotherapy alone 5, 2
• For CPS <5, this remains an option but with lower evidence (category 2B) 5

For HER2-positive tumors:

• Trastuzumab plus chemotherapy is the recommended first-line approach 5
• This combination provides 3-4 months survival benefit 2

For CLDN18.2-expressing tumors:

• Zolbetuximab addition provides 3-4 months additional survival 2

For MSI-H/dMMR tumors:

• Pembrolizumab should be the preferred treatment, with unprecedented response rates and median duration of response not yet reached 6
• Dostarlimab-gxly is an alternative option 5

Second-line therapy:

• Ramucirumab with paclitaxel (preferred) or as single agent 5
• Pembrolizumab for MSI-H/dMMR or TMB-H tumors 5
• For HER2-positive disease progressing on trastuzumab, trastuzumab deruxtecan shows survival benefit 6

Third-line therapy:

• Trifluridine/tipiracil has the strongest evidence base 6
• Alternative: taxane or irinotecan 6
• For NTRK gene fusion-positive tumors: entrectinib or larotrectinib 5

Critical Management Principles

Surgery in metastatic disease:

• The REGATTA trial definitively showed that gastrectomy plus chemotherapy does NOT improve survival versus chemotherapy alone in oligometastatic disease 6
• Surgery should only be performed for palliation of major symptoms (bleeding, obstruction) 1
• Routine resection of oligometastases is not supported by current evidence 6

Supportive care integration:

• Early supportive care focusing on symptom management, nutrition, and psychosocial support is associated with 3 months survival benefit 2
• For gastric outlet obstruction: endoscopic stenting provides immediate relief; radiation takes 4-6 weeks but provides better long-term relief 6
• Venting gastrostomy for decompression when obstruction cannot be bypassed 5

Common Pitfalls to Avoid

• Do not perform gastrectomy in oligometastatic disease outside clinical trials—this does not improve survival 6
• Do not skip biomarker testing (PD-L1, HER2, MSI/dMMR, CLDN18.2, NTRK) in metastatic disease—these directly determine optimal therapy selection 5, 2
• Do not use PET scans routinely for staging—they are not indicated 1
• Do not accept <16 lymph nodes in pathology assessment—this is necessary for adequate staging 1

The evidence strongly supports this stage-based, biomarker-directed approach, with recent guidelines from both ESMO 6 and NCCN 5 converging on these recommendations for 2022-2025.