# Gastro-oesophageal junction (GEJ)

Source: https://onco.cc/terms/gej/  
OnCo record `gej` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Where the food pipe meets the stomach. Cancers here are classed by how far above or below the junction they centre (Siewert I-III), which decides whether they are treated like oesophageal or stomach cancer.

## Summary

Adenocarcinoma of the GEJ has risen sharply in Western countries with obesity and reflux (via Barrett's oesophagus). Siewert type I (mainly oesophageal) is treated with chemoradiation (CROSS) and oesophagectomy; type III (mainly gastric) with perioperative FLOT and extended gastrectomy; type II either way. Drug trials for HER2, PD-L1 and claudin 18.2 usually enrol gastric and GEJ tumours together, so the label 'gastric or GEJ adenocarcinoma' is common on approvals.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: GEJ; GOJ; gastroesophageal junction; gastro-oesophageal junction; oesophagogastric junction; junctional; Siewert; esophagogastric junction

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Gastroesophageal_junction
- Wikipedia: https://en.wikipedia.org/wiki/Gastroesophageal_junction

## Connected records

- terms: [Barrett's oesophagus](https://onco.cc/terms/barretts-esophagus/), [FLOT regimen (perioperative chemotherapy for gastric cancer)](https://onco.cc/terms/flot-term/), [Gastrectomy](https://onco.cc/terms/gastrectomy/), [Oesophagectomy](https://onco.cc/terms/oesophagectomy/)
- drugs: [FLOT (5-FU, leucovorin, oxaliplatin, docetaxel)](https://onco.cc/drugs/flot/)
- cancers: [Gastric & gastro-oesophageal junction cancer](https://onco.cc/cancers/gastric/), [Oesophageal cancer](https://onco.cc/cancers/esophageal/)
- fronts: [Surgery & Interventional](https://onco.cc/fronts/surgery/)
- trials: [CROSS](https://onco.cc/trials/cross/)

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JSON: https://onco.cc/api/v1/entities/gej.json