Stomach cancer treatment: stage, surgery and biomarker choices
Stomach cancer treatment depends first on the exact tumor type and whether it can be removed. Selected very early adenocarcinomas may be treated endoscopically; other localized cancers need surgery with treatment before or afterward when indicated. Advanced disease is commonly treated with systemic medicines chosen partly through HER2, PD-L1, MSI/MMR and CLDN18.2 results. Nutrition, bleeding and obstruction need attention throughout. A useful plan explains both the cancer treatment and how eating and strength will be supported.
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Confirm tumor type and extent
Most discussions of stomach cancer treatment concern adenocarcinoma. A gastric lymphoma, gastrointestinal stromal tumor or neuroendocrine tumor needs a different pathway. The biopsy report should make that distinction clear before a regimen is chosen.
Staging uses the clinical findings and imaging, with additional procedures when they would clarify spread or surgical feasibility. Ask whether the disease is early, locally advanced and removable, or metastatic. The answer determines whether the plan aims at complete local treatment or ongoing systemic control.
Sources and references: [1]
When endoscopic treatment may be enough
Selected very early cancers can be removed through an endoscope. Suitability depends on the depth and other pathological features, as well as whether a complete removal is feasible. An early appearance on a scan is not enough to make that decision.
After endoscopic removal, the specimen can reveal features requiring further treatment. Ask what the pathology needs to show for surveillance to be appropriate and what would lead to surgery. This discussion is separate from choosing drug treatment for advanced gastric cancer.
Sources and references: [1]
Plan surgery and surrounding treatment together
A gastrectomy removes part or all of the stomach, with appropriate lymph-node surgery. The tumor's location and extent influence the operation. For many higher-risk removable cancers, systemic treatment is used before surgery, after surgery or both.
Perioperative options are evolving. In November 2025 the US FDA approved durvalumab with FLOT chemotherapy before and after surgery, followed by durvalumab, for adults with resectable gastric or gastroesophageal junction adenocarcinoma. A Shanghai team should explain which locally applicable regimen fits your stage, fitness and previous treatment.
Ask for a complete biomarker plan in advanced disease
HER2 can guide HER2-directed treatment. PD-L1 is often reported as a combined positive score, or CPS, and helps interpret immune-treatment options. MSI/MMR assesses DNA repair characteristics. CLDN18.2 testing can identify another treatment target.
Ask which tests have been completed, whether the sample is adequate and whether any result could change the first treatment. A short summary saying all tests normal can hide details that matter. Bring the actual pathology and laboratory reports to an additional consultation.
Match the combination to the results
Chemotherapy remains a common backbone for advanced gastric adenocarcinoma. A biomarker-directed antibody or checkpoint inhibitor may be added in a defined setting. HER2-positive and HER2-negative tumors can therefore receive different combinations, even when they have the same stage.
The team should explain the reason for each drug and its expected role. If several biomarkers are positive, ask how competing options are prioritized and whether the combinations have been studied together. Adding every available targeted treatment is not an evidence-based default.
Eating problems can change what treatment is practical
Early fullness, vomiting, weight loss and pain may reduce strength before treatment begins. Tell the team how much you can actually eat and drink. A nutrition plan may involve changes in meal size or texture, supplements or another feeding approach when needed.
Bleeding or obstruction may require an endoscopic, radiotherapy or surgical intervention. Vomiting blood, black stools with weakness, severe abdominal pain or inability to keep fluids down needs prompt local assessment. These problems should be addressed before a long journey for a nonurgent consultation.
Sources and references: [1]
Review benefit and toxicity at planned intervals
Before systemic treatment starts, agree on the timing of scans and what symptoms should trigger earlier review. Treatment can cause nausea, low blood counts, diarrhea or neuropathy; immune and targeted medicines bring additional risks. Early reporting allows supportive care and adjustments.
For postoperative care, follow-up also needs to cover eating, weight and nutritional deficiencies after gastrectomy. Ask who will manage these issues between oncology visits. A complete plan should help you function day to day while monitoring the cancer.
Preparing a stomach cancer review in Shanghai
Fudan University Shanghai Cancer Center has a gastric cancer service. Its hospital profile can help you frame an inquiry about surgery, combined treatment or a further oncology review.
EastMedGo can help organize the endoscopy findings, pathology, scans and biomarker results for the receiving team. Contact us through contact with the treatment decision you are facing and any difficulty eating. We can coordinate consultation requirements and practical arrangements, including expected charges and the sequence of appointments.
Sources and references: [6]
Common questions
Should biomarker testing wait until chemotherapy fails?
For advanced gastric cancer, several biomarkers can affect the first treatment choice. Ask early which tests are needed and whether tissue is sufficient, rather than waiting automatically for progression.
Does all stomach cancer require removal of the whole stomach?
No. The operation depends on the location and extent of disease, and selected very early tumors may be suitable for endoscopic treatment. Ask why the proposed amount of stomach removal is necessary.
Sources and references: [1]
Can treatment start if I am losing weight?
Often it can, but the cause and severity of weight loss need assessment. Nutrition support and treatment of obstruction or vomiting may be needed to make the cancer plan tolerable.
Sources and references: [1]
Sources and references
- Gastric Cancer Treatment (PDQ), Health Professional Version
- FDA approves durvalumab for resectable gastric or gastroesophageal junction adenocarcinoma
- FDA approves zolbetuximab-clzb with chemotherapy for gastric or gastroesophageal junction adenocarcinoma
- FDA approves pembrolizumab for HER2-positive gastric or GEJ adenocarcinoma expressing PD-L1 CPS at least 1
- Chemotherapy to Treat Cancer
- Fudan University Shanghai Cancer Center: gastric surgery
Prepared with AI assistance by EastMedGo for patients comparing treatment and care options.