Bleeding a	Obstruction b	Pain c
Endoscopic treatment: Metallic hemostatic clips Injection therapy: e.g., ethanol, adrenaline Ablation therapy: laser photocoagulation, argon plasma coagulation Medical treatments: Proton pump inhibitors Somatostatin analogs Transcatheter arterial embolization Palliative gastrectomy	Gastrointestinal decompression Endoscopic treatments Stent placement Gastrostomy/jejunostomy Gastrojejunostomy Internal/external radiation therapy Surgical treatments Gastrojejunostomy Gastrostomy/jejunostomy Gastrectomy Chemotherapy d Medical treatments Pain management Antiemetics Antisecretory Antispasmodic	Analgesic: non‐opioid analgesics (acetaminophen or NSAIDs) or opioid analgesics Chemotherapy d External radiotherapy

Abbreviation: NSAIDs, non‐steroidal anti‐inflammatory drugs.

Notes:

^a Hemorrhage is a common symptom of gastric cancer and can be caused by the tumor itself or as a side effect of cancer treatment. Acute and severe hemorrhage can be life‐threatening and require immediate endoscopic examination. However, the effectiveness of endoscopic treatment in hemorrhagic gastric cancer is still not well‐established, and limited data suggest that its initial success rate is high, but the rate of recurrent bleeding is also significant [272]. If endoscopic treatment fails, other options can be considered to control bleeding. Transcatheter arterial embolization (TAE), in which the main blood vessels supplying the stomach are blocked to reduce bleeding, may be an option [273]. Alternatively, palliative gastroctomy can be performed to control bleeding. External radiation therapy can also be effective in managing both acute and chronic hemorrhage but may take time to fully take effect and is more suitable for chronic hemorrhage. Although proton pump inhibitors (PPIs) are commonly believed to be beneficial for chronic bleeding, a randomized study from Korea showed that PPIs did not significantly reduce the occurrence of tumor bleeding [272].

^b The aim of treating gastrointestinal obstruction is to reduce symptoms such as nausea and vomiting and restore intestinal nutrition absorption. The most common causes of obstruction in stomach cancer include pyloric obstruction due to gastric antral cancer, cardia obstruction due to esophagogastric junction cancer, and small bowel obstruction caused by peritoneal metastases. For resectable gastric cancer, if symptoms of obstruction occur, it is recommended to remove the primary tumor to control and improve symptoms. In cases of advanced or non‐operable gastric cancer with pyloric or cardia obstruction, as the effectiveness of medical oncology improves, patients in good nutritional condition can undergo chemotherapy‐based treatment to address the obstruction. For patients with poor nutritional status or those for whom treatment is ineffective, endoscopy can be performed to assess the extent of narrowing and determine if endoscopic interventions are possible, such as stent placement, percutaneous endoscopic gastrostomy/jejunostomy, or ultrasound‐guided gastrojejunostomy [272]. Single‐dose brachytherapy may have superior long‐term efficacy and lesser complication rates compared to metal stent placement. External beam radiation therapy can achieve symptom relief in 75% to 83% of obstruction cases, but it may initially worsen symptoms. Multimodal interventions such as stenting, surgery, endoscopic or internal/external radiation therapy and medical oncology treatment may yield better results. If endoscopic access is challenging, surgical interventions like laparoscopic gastrojejunostomy, gastrostomy/jejunostomy, or palliative gastrectomy should be considered [274, 275]. For small bowel obstruction caused by peritoneal metastases, which is often associated with a “frozen pelvis” presentation and represents a terminal stage of the disease, surgical interventions may be challenging and should generally be avoided. Instead, supportive measures such as nutritional support, spasm relief, antisecretory, antiemetics, and pain management should be employed. Benign strictures of the esophagus and cardia can be treated with esophageal dilation procedures.

^c Patients with gastric cancer often have pain. Cancer pain can be caused by tumor invasion and metastasis, organ involvement, treatment‐related pain such as stent placement, etc. It is important to differentiate surgical emergencies such as perforation or obstruction. Anti‐tumor therapy, such as chemotherapy and radiotherapy, can shrink the tumor and reduce the pain caused by the compression on the nerves or other organs. Cancer pain can be evaluated and managed based on the WHO three‐step analgesic ladder [276]. The common analgesics are opioids, paracetamol, and nonsteroidal anti‐inflammatory drugs. The most common route of administration is oral, and other routes (i.e., intravenous, subcutaneous, rectal, transdermal, and transmucosal) can be considered in patients with gastrointestinal obstruction.

^d Gastric cancer patients are prone to treatment‐related myelosuppression. The related treatments include chemotherapy, targeted therapy, radiotherapy, immunotherapy, and so on. The Common Terminology Criteria for Adverse Events (CTCAE) are commonly used for grading and managing adverse events. For treatment‐related anemia, iron, vitamin B12, and folic acid should be supplemented, especially in patients after gastrectomy, after hemorrhagic or nutritional anemia was ruled out. For treatment‐related anemia, recombinant erythropoietin (EPO) can be given. A red cell suspension can be given if necessary. For treatment‐related granulocytopenia, recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) or long‐acting rhG‐CSF (polyglycosylated rhG‐CSF) can be considered for prophylactic or therapeutic use accordingly. For treatment ‐related thrombocytopenia, the bleeding degree or risk should be first assessed. Based on the assessment and patient's conditions, measures such as giving thrombopoietin (TPO), interleukin (IL)‐11, and platelet infusion can be implemented.