GASTROESOPHAGEAL JUNCTION CANCER:
DIAGNOSIS AND TREATMENT
A complete patient guide to cancer at the gastroesophageal junction โ how it is diagnosed, staged, classified, and treated with surgery, perioperative chemotherapy, targeted therapy, and immunotherapy.
analyticsAt a Glance
- check_circleGEJ cancer arises where the oesophagus meets the stomach โ Siewert type determines surgical approach and treatment protocol
- check_circleFLOT perioperative chemotherapy has become the standard approach for resectable GEJ tumours
- check_circleHER2 testing and PD-L1 CPS scoring are mandatory โ both inform first-line treatment selection
- check_circleCancerFax coordinates access to GEJ cancer specialists in China and India
What Is Gastroesophageal Junction Cancer?
Gastroesophageal junction (GEJ) cancer โ also called cardia cancer, oesophagogastric junction cancer, or type II/III Siewert tumour โ arises at the anatomical transition zone between the distal oesophagus and the proximal stomach. Its incidence has increased significantly in Western countries over recent decades, partly driven by rising rates of gastroesophageal reflux disease and Barrett's oesophagus.
โGEJ cancer sits at a clinical crossroads โ it is neither purely gastric nor purely oesophageal, and its management reflects elements of both disciplines.โ
Siewert Type I โ Lower Oesophageal
Adenocarcinoma of the distal oesophagus with epicentre 1โ5 cm above the anatomical cardia. Usually associated with Barrett's oesophagus and treated primarily as oesophageal cancer โ transthoracic surgical approach, oesophageal cancer chemotherapy protocols.
Siewert Type II โ True Cardia
Adenocarcinoma arising from the true cardia (1 cm above to 2 cm below the anatomical cardia). The most debated subtype โ treated as either gastric or oesophageal depending on surgical and oncological team preference and tumour extension.
Siewert Type III โ Subcardial Gastric
Adenocarcinoma with epicentre 2โ5 cm below the anatomical cardia. Treated primarily as gastric cancer โ transhiatal or extended total gastrectomy, gastric cancer chemotherapy protocols (FLOT, FOLFOX, XELOX).
Why Siewert Type Matters
Siewert classification determines the surgical approach, the chemotherapy protocol used perioperatively, and which clinical trials the patient is eligible for. Misclassification can lead to inappropriate surgical planning. Expert GI surgical oncology second opinion is strongly recommended for all GEJ tumours.
GEJ Cancer Diagnostic Workup
A complete and accurate diagnostic workup is essential for GEJ cancer โ both to determine resectability and to guide biomarker-driven treatment selection.
- 1
Upper GI Endoscopy and Biopsy
Upper GI endoscopy with biopsies of the GEJ tumour is the primary diagnostic procedure. Biopsies should be taken from the tumour and, if Barrett's oesophagus is suspected, from the oesophageal mucosa proximal to the tumour.
- 2
CT Chest/Abdomen/Pelvis with IV Contrast
Cross-sectional CT is the primary staging modality โ assessing locoregional nodal involvement, distant metastasis (liver, lungs, peritoneum), and vascular invasion. Essential before any surgical planning.
- 3
Endoscopic Ultrasound (EUS)
EUS provides the most accurate T-staging (depth of wall invasion) and locoregional N-staging for GEJ tumours โ essential for determining resectability and eligibility for perioperative versus definitive chemoradiotherapy.
- 4
PET-CT
FDG-PET CT is recommended for GEJ cancer staging, particularly to exclude occult distant metastatic disease that CT may miss โ peritoneal metastases and small distant lymph node deposits are better detected on PET.
- 5
Biomarker Testing โ HER2, PD-L1 CPS, MSI/MMR, CLDN18.2
Mandatory biomarker panel for all advanced/locally advanced GEJ cancer: HER2 IHC + ISH, PD-L1 CPS, MSI/MMR by IHC or PCR, and CLDN18.2 by IHC. These four tests determine first-line treatment selection.
- 6
Laparoscopic Staging
Diagnostic laparoscopy is recommended before committing to perioperative chemotherapy and curative resection in locally advanced GEJ cancer โ peritoneal metastases are found in ~10โ15% of patients who appear M0 on cross-sectional imaging.
GEJ Cancer Treatment by Disease Stage
A structured overview of the standard treatment approach for each stage of gastroesophageal junction cancer โ from resectable disease through to metastatic management.
| Stage | Resectability Status | Treatment Approach | Notes |
|---|---|---|---|
| Stage I (T1โ2 N0 M0) | Resectable | Surgery alone or surgery + adjuvant S-1/capecitabine | Perioperative chemotherapy debated for T1โ2N0 |
| Stage IIโIII (locally advanced) | Resectable | Perioperative FLOT (4 cycles pre + 4 cycles post-op surgery) | Standard of care for Siewert II/III; CROSS for Siewert I |
| Stage III (borderline resectable) | Borderline / assess | Intensified perioperative chemo ยฑ restaging surgery | Specialist MDT assessment essential |
| Stage IV (metastatic, HER2+) | Unresectable | Trastuzumab + chemotherapy ยฑ PD-1 inhibitor | ToGA/T-DXd backbone; add nivolumab if CPS โฅ5 |
| Stage IV (metastatic, CLDN18.2+/HER2โ) | Unresectable | Zolbetuximab + FOLFOX/CAPOX | SPOTLIGHT/GLOW trial protocol; NMPA approved China |
| Stage IV (metastatic, MSI-H) | Unresectable | Pembrolizumab or nivolumab ยฑ chemotherapy | First-line IO recommended in MSI-H |
| Stage IV (metastatic, all-comers) | Unresectable | FOLFOX/XELOX/SOX + nivolumab (if CPS โฅ5) | CheckMate-649 regimen |
Gastroesophageal Junction Cancer โ Key Numbers
Clinical figures that contextualise the disease burden and key treatment outcomes for GEJ cancer.
- RisingGEJ cancer incidence trend globallyGEJ adenocarcinoma incidence has increased 2โ3-fold in Western countries over 30 years โ unlike distal gastric cancer, which is declining.
- ~15โ20%HER2 positivity rate in GEJ and gastric adenocarcinomaThe single most actionable biomarker in GEJ cancer โ HER2 testing should be performed at diagnosis for all advanced/metastatic disease.
- ~35%5-year overall survival with perioperative FLOT + surgery (FLOT4 trial)The FLOT4 trial demonstrated superior OS over the older ECF/ECX regimen โ establishing FLOT as the perioperative standard for resectable GEJ cancer.
More from the Gastric Cancer Resource Library
Explore related guides on gastric cancer biomarkers, immunotherapy, and treatment access in China.
Frequently Asked Questions About GEJ Cancer
Is gastroesophageal junction cancer treated as gastric cancer or oesophageal cancer?
It depends on the Siewert type. Siewert type I GEJ cancer (predominantly distal oesophageal) is treated as oesophageal cancer โ with transthoracic surgery and the CROSS (chemoradiotherapy) perioperative approach. Siewert type III (predominantly subcardial gastric) is treated as gastric cancer โ with total gastrectomy and FLOT perioperative chemotherapy. Siewert type II is the most contested โ management depends on surgical expertise and institutional practice, with both oesophageal and gastric protocols applied. Expert multidisciplinary review is essential.
What is FLOT chemotherapy and why is it used for GEJ cancer?
FLOT (docetaxel, oxaliplatin, leucovorin, 5-fluorouracil) is the perioperative chemotherapy regimen that has replaced ECF/ECX as the standard for resectable gastric and GEJ cancer in most Western and Chinese guidelines. The FLOT4 trial demonstrated a 3.4-month improvement in median OS over ECF/ECX (50 vs 43 months) with improved R0 resection rates โ establishing FLOT as the current standard for Siewert II/III resectable disease.
Can I get a second opinion on my GEJ cancer staging and treatment plan through CancerFax?
Yes โ and for GEJ cancer specifically, a second opinion is strongly recommended given the complexity of Siewert classification, the importance of accurate staging for surgical planning, and the rapidly evolving biomarker-driven treatment landscape. CancerFax coordinates remote or in-person second opinion consultations with specialist GI surgical oncologists and medical oncologists at leading centres in China and India, reviewing your endoscopy, imaging, pathology, and biomarker results in full.
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination โ travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
Recently Diagnosed With GEJ Cancer? CancerFax Can Help.
CancerFax reviews your GEJ cancer records โ Siewert type, staging, HER2 status, PD-L1 CPS, and surgical assessment โ and coordinates access to specialist centres in China and India for second opinions, advanced treatment, or clinical trial matching.
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.