Oesophagogastric Junction Cancer

Oesophagogastric junction cancer arises around the anatomical transition between distal oesophagus and proximal stomach. Most are adenocarcinomas.

The Siewert classification remains useful for surgical planning:

• Type I: tumour centre 1 to 5 cm above the junction
• Type II: tumour centre from 1 cm above to 2 cm below the junction
• Type III: tumour centre 2 to 5 cm below the junction

Type I behaves predominantly as distal oesophageal cancer. Type III behaves predominantly as proximal gastric cancer. Type II lies between these patterns and requires careful assessment of proximal and distal extension and lymphatic drainage.

Progressive dysphagia is common when oesophageal involvement is substantial.

Other presentations include:

• Early satiety
• Weight loss
• Epigastric or retrosternal discomfort
• Anaemia
• Gastrointestinal bleeding
• Regurgitation

Advanced proximal gastric disease may present with less dysphagia than a similarly sized distal oesophageal tumour.

Upper gastrointestinal endoscopy with biopsy: establish histology and accurately document the tumour centre relative to the junction.

CT chest, abdomen and pelvis plus PET CT where appropriate: establish metastatic disease and resectability.

Endoscopic ultrasound: defines local depth and regional nodes when potentially curative treatment is planned.

Staging laparoscopy with peritoneal washings is particularly important when the tumour has a substantial gastric component, advanced T stage, nodal disease or poorly cohesive histology because small volume peritoneal disease can be missed on conventional imaging.

Treatment requires both appropriate systemic therapy and an operation that provides an R0 resection with adequate lymphadenectomy.

Perioperative therapy

For resectable gastric and gastroesophageal junction adenocarcinoma, durvalumab plus FLOT is now an approved perioperative option and produced better event free survival than FLOT alone.

FLOT every 14 days:

• Docetaxel 50 mg/m² IV
• Oxaliplatin 85 mg/m² IV
• Leucovorin 200 mg/m² IV
• Fluorouracil 2600 mg/m² continuous infusion over 24 hours

Four FLOT treatments are given before surgery and four after surgery.

For patients weighing at least 30 kg:

Durvalumab 1500 mg IV every 4 weeks with perioperative chemotherapy for up to four durvalumab cycles, followed by durvalumab 1500 mg IV every 4 weeks for up to ten additional cycles.

Availability and regulatory approval vary by country.

FLOT without immunotherapy remains a valid perioperative regimen where durvalumab is unavailable or inappropriate.

Surgery

Siewert I: usually treated with transthoracic oesophagectomy and mediastinal plus upper abdominal lymphadenectomy.

Siewert III: generally treated as gastric cancer with total gastrectomy, distal oesophageal resection and appropriate perigastric lymphadenectomy.

Siewert II: the operation is individualised according to tumour extension. Transthoracic oesophagectomy is favoured when oesophageal involvement and mediastinal nodal risk dominate. Extended total gastrectomy with distal oesophagectomy may be appropriate when disease is predominantly gastric and an adequate proximal margin can be achieved.

The objective is anatomical, not semantic: achieve an R0 resection while removing the lymphatic basin at greatest risk.

Metastatic or unresectable disease requires biomarker directed systemic therapy. Test adenocarcinoma for HER2, PD L1, MSI or mismatch repair deficiency and relevant additional targets.