Symptoms or abnormal findings
Persistent indigestion, weight loss, anemia, vomiting, black stools, abdominal pain or abnormal imaging may lead to further evaluation.
Gastric Cancer Education · Endoscopy · Biopsy · CT · EUS · TNM
Stomach Cancer Diagnosis & Staging
Stomach cancer diagnosis and staging help confirm whether a gastric tumor is present, define the cancer type, identify important biomarkers, measure how deeply the tumor has grown into the stomach wall, check nearby lymph nodes and determine whether cancer has spread to distant organs or the peritoneum.
Educational information only. This page does not provide diagnosis, screening
instructions, treatment recommendations or medical advice.
Endoscopy
Biopsy
EUS
CT / PET
TNM
Diagnosis Overview
How stomach cancer may be diagnosed
Stomach cancer is usually confirmed by examining tissue from the stomach under a microscope. Endoscopy helps doctors see the stomach lining and take biopsy samples. Imaging and other tests help determine stage and treatment planning.
Endoscopy and biopsy
Upper endoscopy allows direct visualization of the stomach lining and biopsy of suspicious areas.
Pathology, imaging and staging
Pathology confirms cancer type. Imaging, endoscopic ultrasound and staging procedures help define tumor depth, lymph nodes and metastasis.
Diagnosis Pathway
Common steps in stomach cancer evaluation
The exact diagnostic pathway depends on symptoms, age, risk factors, endoscopy findings, biopsy results, tumor location and whether cancer appears localized, regional or metastatic.
1
Medical history and physical exam
The care team reviews symptoms, weight change, appetite, bleeding signs, anemia, family history, H. pylori history, reflux and prior endoscopy results.
2
Upper endoscopy
A thin flexible scope is passed through the mouth to inspect the esophagus, stomach and first part of the small intestine.
3
Biopsy
Small tissue samples are taken from suspicious stomach areas. Biopsy is used to confirm whether cancer is present.
4
Pathology review
Pathology identifies adenocarcinoma or another tumor type and may report grade, histologic pattern, invasion and biomarker testing.
5
Imaging and endoscopic ultrasound
CT, PET/CT, MRI or endoscopic ultrasound may help estimate tumor extent, wall invasion, lymph nodes and distant spread.
6
Staging laparoscopy when needed
In selected cases, laparoscopy may check for small peritoneal spread that may not be visible on imaging.
Diagnostic Map
Endoscopy
Biopsy
Pathology
Imaging
Stage
Diagnostic Tests
Tests used in stomach cancer diagnosis and staging
Tests may include endoscopy, biopsy, pathology, imaging, endoscopic ultrasound, laparoscopy and blood tests. ACS states that tests for stomach cancer may include endoscopy, biopsy, imaging tests and lab tests.
Upper endoscopy
Directly examines the stomach lining and allows biopsy of abnormal areas.
Biopsy
Removes tissue for microscopic examination. Biopsy is central to confirming a stomach cancer diagnosis.
Pathology
Determines tumor type, grade, histologic features and sometimes molecular or biomarker results.
Endoscopic ultrasound
Uses ultrasound from inside the digestive tract to estimate tumor depth and nearby lymph-node involvement.
CT scan
Helps assess stomach wall thickening, lymph nodes, nearby organs, liver lesions or other signs of spread.
PET/CT
May help identify metabolically active disease or distant spread in selected staging situations.
Staging laparoscopy
A minimally invasive procedure that may identify peritoneal disease not visible on scans.
Blood tests
May assess anemia, liver function, nutrition, inflammation and overall treatment readiness.
Endoscopy + Biopsy
Scope
Mucosa
Sample
Pathology
Endoscopy & Biopsy
Why biopsy matters for diagnosis
Imaging can suggest stomach wall thickening or spread, but the diagnosis of gastric cancer is confirmed by tissue examination. Endoscopy allows direct inspection of the gastric mucosa and targeted biopsy.
Endoscopy sees the surface
Doctors can inspect ulcers, masses, thickened folds, bleeding areas or abnormal mucosa.
Biopsy confirms cancer
Pathologists examine tissue architecture and cell features to confirm cancer type.
Biomarker tests may be added
HER2, MSI/MMR, PD-L1, EBV or CLDN18.2 testing may be relevant depending on case and care setting.
TNM Staging
How stomach cancer staging works
Stomach cancer staging usually uses the TNM system. TNM describes the primary tumor depth, lymph-node involvement and whether cancer has spread to distant body sites. NCI states that TNM results are used to assign stage I, II, III or IV.
T
Tumor depth
Describes how deeply the tumor has grown into the stomach wall and whether it reaches nearby structures.
N
Lymph nodes
Describes whether stomach cancer has spread to nearby regional lymph nodes and how many nodes are involved.
M
Metastasis
Describes whether cancer has spread to distant organs, distant lymph nodes or the peritoneum.
TNM Stage
T Depth
Nodes
Metastasis
Wall Layers
Peritoneum
Stage Groups
Stage 0 to stage IV stomach cancer
Stage grouping summarizes the TNM pattern. Lower stage generally means less spread; higher stage means deeper invasion, more lymph-node involvement or distant spread.
Stage 0
Abnormal cells are limited to the inner lining and have not invaded deeper stomach wall layers.
Stage I
Early invasive stomach cancer, often limited to inner layers or with limited regional node involvement.
Stage II
Cancer has grown more deeply or involves more nearby lymph nodes, but distant spread is not present.
Stage III
Cancer usually involves deeper stomach wall invasion, nearby structures or more regional lymph nodes.
Stage IV
Cancer has spread to distant organs, distant lymph nodes or the peritoneum. This is also called metastatic stomach cancer.
Pathology & Biomarkers
What a stomach cancer pathology report can show
Pathology confirms cancer type and may include features used in staging, prognosis, tumor classification and treatment discussions.
Cancer type
Gastric adenocarcinoma, diffuse-type, intestinal-type, signet-ring, GIST, lymphoma or neuroendocrine tumor.
Grade and differentiation
Describes how abnormal cancer cells look and how closely they resemble normal gland cells.
Depth of invasion
Helps determine the T category when surgical tissue is available.
Lymphovascular invasion
Reports whether cancer cells are seen in blood vessels or lymphatic channels.
Margins
After resection, margins show whether cancer cells are present at the tissue edge.
Biomarkers
HER2, MSI/MMR, PD-L1, EBV and CLDN18.2 may be tested depending on clinical context.
Question Builder
Questions to ask after stomach cancer testing
Select a topic to reveal practical questions for endoscopy, biopsy, imaging, biomarkers, staging or pathology appointments.
Endoscopy questions
- Where in the stomach was the abnormal area found?
- Was the tumor in the cardia, body, antrum or pylorus?
- Were multiple biopsies taken?
- Do I need repeat endoscopy, endoscopic ultrasound or staging imaging?
Simple Summary
Stomach cancer diagnosis and staging in simple terms
Diagnosis confirms whether cancer is present. Staging explains how far stomach cancer has grown or spread.
How is stomach cancer usually diagnosed?
Stomach cancer is usually diagnosed with upper endoscopy and biopsy. A pathologist examines the tissue under a microscope.
What tests help stage stomach cancer?
Tests may include CT, PET/CT, MRI, endoscopic ultrasound, laparoscopy and blood tests depending on the case.
What does TNM mean?
TNM means Tumor, Nodes and Metastasis. It describes tumor depth, lymph-node spread and distant spread.
FAQ
FAQ: Stomach Cancer Diagnosis & Staging
Clear answers to common diagnosis and staging search questions.
How is stomach cancer diagnosed?
Stomach cancer is usually diagnosed by upper endoscopy with biopsy. The biopsy sample is examined by a pathologist to confirm whether cancer is present.
Can a CT scan diagnose stomach cancer?
A CT scan can show suspicious findings and help stage disease, but tissue biopsy is needed to confirm a stomach cancer diagnosis.
What is endoscopic ultrasound used for?
Endoscopic ultrasound helps estimate how deeply a stomach tumor has grown into the stomach wall and whether nearby lymph nodes may be involved.
How is stomach cancer staged?
Stomach cancer is usually staged with the TNM system, which describes tumor depth, lymph-node involvement and distant metastasis.
Is this page medical advice?
No. This page is educational only and does not replace consultation with a qualified healthcare professional.
References
Scientific References
Authoritative sources used to support this stomach cancer diagnosis and staging page.
- National Cancer Institute. Stomach cancer diagnosis and tests.
- National Cancer Institute. Stomach cancer stages and TNM staging.
- American Cancer Society. Stomach cancer early detection, diagnosis and staging.
- Cancer Research UK. TNM staging for stomach cancer.
- Clinical literature on gastric cancer diagnosis, staging imaging, endoscopy, biopsy, EUS and biomarker testing.