Stomach (Gastric) Cancer
A cancer of the stomach lining where molecular testing for HER2, MSI, and PD-L1 status increasingly determines access to targeted therapy and immunotherapy beyond chemotherapy.
- HER2/MSI/PD-L1 testing guidance
- Multidisciplinary surgical planning
- Targeted therapy access
- Specialist second opinion
- Most Common In
- Adults over 50
- Leading Risk Factor
- H. pylori infection
- Key Biomarkers
- HER2, MSI-H, PD-L1, Claudin 18.2
- Advanced Therapies
- HER2-targeted ADCs, Immunotherapy
Condition Overview
Stomach (gastric) cancer arises from the lining of the stomach, most commonly as adenocarcinoma. It is frequently diagnosed at a locally advanced or metastatic stage because early symptoms are vague and overlap with common digestive complaints. Risk is influenced by Helicobacter pylori infection, diet, and in a smaller subset, inherited genetic factors.
Molecular classification — including HER2 status, microsatellite instability (MSI-H), and EBV positivity — has become central to modern treatment planning, opening the door to targeted and immune-based therapies beyond standard chemotherapy.
Types and Subtypes
Gastric cancer is classified by histologic pattern (Lauren classification) and increasingly by molecular subtype, both of which affect prognosis and treatment selection.
Symptoms and Signs
Early gastric cancer often causes few or nonspecific symptoms, which is a major reason for delayed diagnosis in many patients.
Causes and Risk Factors
Gastric cancer risk is influenced by a combination of infectious, dietary, and genetic factors.
Diagnosis and Investigations
Diagnosis combines endoscopic visualization and tissue sampling with staging imaging and increasingly, molecular testing.
Staging and Risk Groups
Gastric cancer staging follows the TNM system based on depth of tumor invasion (T), lymph node involvement (N), and distant metastasis (M), which together determine overall stage and risk grouping.
Standard Treatment Options
Treatment is tailored to stage, resectability, and molecular profile, generally coordinated by a multidisciplinary team.
Advanced & Emerging Therapies
Molecular profiling has expanded treatment options for gastric cancer well beyond standard chemotherapy.
HER2-Targeted Therapy
Trastuzumab-based regimens and antibody-drug conjugates
Used for HER2-positive gastric cancer, including newer antibody-drug conjugates for patients who progress after first-line HER2-targeted treatment.
Immunotherapy
PD-1 checkpoint inhibitors
Used in combination with chemotherapy for advanced disease, with particular benefit in MSI-H and high PD-L1-expressing tumors.
Antibody-Drug Conjugate
Claudin 18.2-targeted therapy
An emerging targeted option for tumors expressing claudin 18.2, an increasingly recognized gastric cancer biomarker.
Precision Oncology
Comprehensive genomic profiling
Used to identify additional actionable alterations and guide clinical trial matching in advanced disease.
Biomarkers & Precision Medicine
Several biomarkers are now routinely tested in gastric cancer to guide treatment selection.
When a Second Opinion May Be Important
Gastric cancer treatment decisions are complex and benefit substantially from multidisciplinary, specialist input at key decision points.
Clinical Trials & Research
Prognosis & Outcome Factors
Outcomes in gastric cancer vary considerably by stage at diagnosis, molecular subtype, and access to the full range of modern systemic therapy; outcomes for advanced disease have improved with the introduction of targeted and immune-based treatments.
Supportive Care and Living With Gastric Cancer
Nutritional support is especially central to supportive care in gastric cancer, given the stomach's role in digestion.
How CancerFax Helps You Explore Treatment Options
CancerFax can help you review your pathology and molecular testing results, coordinate a specialist surgical and medical oncology second opinion, and connect you with centers experienced in HER2-targeted therapy, immunotherapy, and complex gastric surgery, including options abroad.
Get a free case reviewFrequently Asked Questions
Early signs are often vague and can include indigestion, early fullness after eating, mild abdominal discomfort, and unintentional weight loss.
Chronic H. pylori infection is the leading known risk factor, along with diet, smoking, chronic gastritis, and in some cases inherited genetic mutations such as CDH1.
Through upper endoscopy with biopsy, followed by staging imaging and molecular testing including HER2, MSI, and PD-L1.
Treatment typically combines chemotherapy with surgical resection for localized and locally advanced disease, and systemic therapy — including targeted agents and immunotherapy when appropriate — for advanced disease.
It means the tumor overexpresses the HER2 protein, making it eligible for HER2-targeted antibody therapies and antibody-drug conjugates.
Yes, particularly for tumors with MSI-H status or high PD-L1 expression, immunotherapy is increasingly combined with chemotherapy in advanced disease.
Intestinal type forms gland-like structures and is linked to H. pylori and chronic gastritis, while diffuse type spreads through the stomach wall without gland formation and can be associated with inherited CDH1 mutations.
Not necessarily — the extent of surgery depends on tumor location and size; some patients require only partial gastrectomy.
With nutritional counseling, vitamin B12 and iron supplementation, and dietary adjustments to manage digestion changes after surgery.
Yes. CancerFax can review your diagnostic and molecular reports, help coordinate a specialist second opinion, and identify centers — including options in China and internationally — experienced with advanced therapy access for Stomach (Gastric) Cancer. We also help with hospital and doctor matching and logistics for patients considering treatment abroad.
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