Stage 4 gastric cancer signifies that cancer has spread to distant body parts. While endoscopy is recognized for diagnosing stomach conditions, its function significantly adapts in advanced cancer. At this stage, endoscopy remains a valuable procedure, shifting its focus to managing the disease, alleviating symptoms, and guiding treatment decisions.
The Role of Endoscopy in Advanced Gastric Cancer
Once stage 4 gastric cancer is diagnosed, endoscopy’s purpose shifts from detection to ongoing management. A primary goal is palliation, improving quality of life by alleviating uncomfortable tumor-related symptoms. This differs from early-stage endoscopy, which aims to diagnose and potentially remove localized tumors.
Another objective is guiding systemic therapy by collecting specific tumor information. This helps make treatments like chemotherapy, targeted therapy, or immunotherapy more effective, tailoring treatment plans. Endoscopy provides direct access to the tumor for symptom relief and detailed analysis.
Palliative Endoscopic Procedures
Relieving Obstructions
Gastric tumors can obstruct food passage, causing difficulty swallowing or gastric outlet obstruction. Endoscopic procedures address these blockages to improve comfort and nutritional intake. Self-expanding metal stents (SEMS) are commonly placed to open narrowed areas in the esophagus or stomach, allowing patients to eat more comfortably. This minimally invasive approach provides rapid symptom relief.
Controlling Bleeding
Stomach tumors can bleed, causing anemia, fatigue, or vomiting blood. Endoscopic hemostasis techniques stop this bleeding directly. Methods include argon plasma coagulation (APC), which uses electrical current to coagulate tissue. Other techniques involve injecting agents, applying mechanical clips, or using thermal probes to seal bleeding vessels. These interventions help stabilize the patient.
Nutritional Support
Patients with advanced gastric cancer may struggle to eat due to obstruction, nausea, or weakness, leading to malnutrition. Endoscopy facilitates feeding tube placement for nutritional support. A percutaneous endoscopic gastrostomy (PEG) tube is inserted into the stomach, or a percutaneous endoscopic jejunostomy (PEJ) tube into the jejunum. These tubes bypass the mouth and esophagus, allowing direct delivery of nutrition, fluids, and medications.
Tumor Debulking
Endoscopy can also reduce tumor size within the stomach, a process called debulking. This alleviates pressure or obstruction symptoms not treatable by stents or other palliative measures. Techniques like laser therapy or argon plasma coagulation (APC) can ablate or shrink parts of the tumor. While not curative, debulking can improve a patient’s quality of life by reducing tumor burden.
Diagnostic and Monitoring Applications
Endoscopy gathers tumor information to inform treatment strategies, beyond immediate symptom relief. A key application is obtaining tumor biopsies for molecular profiling. These biopsies allow testing of the tumor’s genetic and molecular characteristics.
Doctors test for markers like human epidermal growth factor receptor 2 (HER2) overexpression, programmed cell death-ligand 1 (PD-L1) expression, and microsatellite instability (MSI) status. These results determine if a patient might benefit from targeted therapies, which attack cancer cells with specific molecular features, or immunotherapy, which helps the body’s immune system fight cancer.
Endoscopy also provides a direct visual assessment of the primary tumor, offering insights into its response to systemic treatments. This visual information, combined with imaging, helps monitor how the cancer reacts to therapy.
The Endoscopy Procedure and Recovery
Before an endoscopy, patients fast for several hours to ensure an empty stomach. Discussions with the medical team are important, especially regarding medications like blood thinners, which may need adjustment. These preparations help ensure a clear view and minimize complications.
During the endoscopy, patients receive sedation or anesthesia for comfort. A thin, flexible tube with a camera, an endoscope, is gently guided through the mouth, down the esophagus, and into the stomach. The patient will not experience pain during this process.
Following the procedure, patients are monitored as sedation wears off. Common, mild side effects include a temporary sore throat or bloating, which resolve quickly. The medical team provides instructions on resuming eating and drinking, and what to expect during recovery. While endoscopy is considered safe, potential risks include minor bleeding, a small tear or perforation in the gastrointestinal tract, or adverse reactions to sedation. Patients should discuss these possibilities with their doctor to understand the risks and benefits.