Gastric tumors are growths arising from the stomach. The large majority, about 85%, are gastric adenocarcinoma, a cancer of the stomach’s glandular lining, or its subtypes. The other, less frequent gastric cancers are neuroendocrine tumours such as carcinoid tumours (tumours of hormone-producing cells), primary gastric lymphoma (a lymphoid-tissue cancer arising in the stomach), and gastrointestinal stromal tumours, or GISTs.
Adenocarcinoma is the dominant subject because it is the commonest gastric cancer, and its course can be followed step by step: chronic mucosal inflammation (the mucosa is the stomach’s inner lining) gives way to premalignant change, a tumour then forms and stays silent for a long time, and by the time it presents the stage usually decides what can be done.
Where to start
- Epidemiology and Prevention — where and in whom gastric cancer occurs, and how H. pylori and surveillance are used to reduce it.
- Premalignant Conditions — the chronic changes of the stomach that precede cancer, and their rates of progression.
- Adenocarcinoma Pathogenesis — the multistep sequence, the risk factors, and the Lauren and Siewert types.
- Molecular Genetics — the molecular subtypes of gastric cancer and the markers tested clinically.
- Clinical Manifestations — how gastric cancer presents, and the signs of metastatic spread.
- Diagnosis — endoscopy, its indications, and the endoscopic classification of early lesions.
- Staging Workup — the imaging and laparoscopic steps that stage the tumour.
- Classification and Staging — early versus advanced disease and the TNM system.
- Treatment — endoscopic resection, surgery, and the systemic therapy chosen by stage and marker.
- Prognosis — what stage, tumour site and biology mean for survival.
If you are new to the topic, start with the epidemiology and work in order. If you already know the disease and want the practical picture, the clinical manifestations, diagnosis and treatment give it directly.