Stage IV gastric cancer represents the most advanced form of stomach cancer, where the disease has spread beyond its original location to distant parts of the body or deeply into surrounding organs and tissues, fundamentally changing the approach to treatment and care.
Understanding Stage IV Gastric Cancer
Stage IV gastric cancer means that the cancer has progressed to its most advanced form. At this stage, the cancer has either grown through the stomach wall and invaded nearby organs or tissues, or it has traveled to distant parts of the body such as the liver, lungs, or distant lymph nodes (small bean-shaped organs that are part of the immune system). In some cases, it can reach the peritoneum, which is the tissue lining that covers the abdominal cavity.[1]
When doctors talk about stage IV stomach cancer, they often divide it into two groups. Stage 4A refers to cancer that has grown through the stomach wall into nearby organs or tissues and might have spread to nearby lymph nodes, but hasn’t yet reached distant body parts. This is sometimes called locally advanced cancer. Stage 4B, on the other hand, means the cancer has spread to distant organs or body parts. This type of spread is called metastatic or secondary cancer.[1]
The stomach is a J-shaped organ in the upper abdomen that plays a central role in digestion. Its wall is made up of five distinct layers, starting from the innermost mucosa (a lining made of cells that produce digestive juices and protective mucus), followed by the submucosa (connective tissue containing blood vessels and nerves), the muscle layer (which helps mix and move food), the subserosa (another thin layer of connective tissue), and finally the serosa (the outermost protective layer). Most stomach cancers begin in the mucosa and spread through these layers as they grow.[2]
Stage IV gastric cancer is harder to treat than earlier stages because it is no longer confined to just the stomach. It may involve several distant organs, making complete removal of all cancer cells through surgery alone extremely difficult. While this stage is usually not curable, it is certainly treatable, and the goal of treatment shifts to controlling the cancer’s growth, easing symptoms, and maintaining the best possible quality of life for as long as possible.[4]
How Common Is Stage IV Gastric Cancer
Gastric cancer is the fourth most common cancer worldwide, with nearly 1 million new cases diagnosed each year. Regionally, about half of all cases occur in Eastern Asia. Stomach cancer is also the second leading cause of cancer-related deaths globally, accounting for approximately 738,000 deaths annually. Unfortunately, many patients are diagnosed at advanced stages, which contributes to the poor survival rates.[8]
In countries like the United States, stomach cancer is less common than in other parts of the world. However, when it is diagnosed, it is often found at a later stage because early symptoms tend to be vague and easily mistaken for other common digestive problems. The lack of widespread screening programs in countries with lower incidence rates also means that many cases are discovered only after the cancer has already spread.[3]
Stage IV disease represents a significant portion of gastric cancer diagnoses. Studies from Japan and Korea have shown that even with advanced medical care and standardized treatment strategies, the outlook for stage IV patients remains challenging. Five-year survival rates for stage IV gastric cancer range from about 15% to 18% in these regions, though outcomes vary widely depending on multiple factors including the patient’s overall health, the specific characteristics of the cancer, and the treatments received.[8]
Where Gastric Cancer Spreads
When stomach cancer reaches stage IV, it can spread to various parts of the body. The most common locations include the liver, which is often affected because blood from the stomach flows through the liver as part of normal circulation. The lungs are another frequent destination for metastatic stomach cancer cells, which can travel through the bloodstream or lymphatic system. Distant lymph nodes, particularly those in areas far from the stomach such as the left supraclavicular lymph node (located above the collarbone), can also become involved.[1]
The peritoneum, which is the thin layer of tissue lining the inside of the abdomen and covering most abdominal organs, is particularly vulnerable to stomach cancer spread. When cancer cells reach the peritoneum, they can cause fluid to build up in the abdominal cavity, a condition called ascites. This can lead to abdominal swelling and discomfort. Understanding where the cancer has spread helps doctors plan treatment and anticipate potential complications.[1]
Treatment Options for Stage IV Gastric Cancer
Treatment for stage IV gastric cancer focuses on controlling the cancer and helping patients maintain the best possible quality of life. Unlike earlier stages where cure is the primary goal, stage IV treatment is considered palliative, meaning it aims to relieve symptoms, slow the cancer’s progression, and extend survival while managing side effects. The specific treatments offered depend on many factors including the patient’s age, overall health, other medical conditions, where exactly the cancer has spread, and specific characteristics of the cancer cells themselves.[1]
Chemotherapy
Chemotherapy is usually offered for stage IV stomach cancer to help shrink tumors and control the growth of cancer. These powerful drugs work by killing fast-growing cancer cells throughout the body. Chemotherapy may be given as a single drug or as a combination of drugs, and treatment typically happens every two weeks. Common chemotherapy drugs used include fluorouracil (also called 5-FU), capecitabine, cisplatin, docetaxel, epirubicin, leucovorin, and oxaliplatin. These can be given alone or in various combinations depending on what works best for each patient.[7]
The side effects of chemotherapy can be significant and may include fatigue, nausea, hair loss, mouth sores, and increased risk of infections. However, newer supportive care medications can help manage many of these side effects. Doctors monitor patients closely during chemotherapy, adjusting doses or changing drugs if needed to balance effectiveness with tolerability.[7]
Targeted Therapy
Targeted therapy represents a more personalized approach to treating advanced stomach cancer. These drugs are designed to attack specific features of cancer cells while leaving normal cells relatively unharmed. All patients with advanced gastric cancer should undergo special testing to see if their cancer has certain markers that make it suitable for targeted therapy.[7]
For patients whose stomach cancer makes too much of a protein called HER2 (called HER2-positive stomach cancer), the targeted drug trastuzumab (Herceptin) can be used in combination with chemotherapy. Studies have shown this combination can improve survival for these patients. Roughly 20% of patients with gastric cancer have HER2-positive disease. If trastuzumab stops working, another drug called trastuzumab deruxtecan may be tried.[7]
Another targeted drug, ramucirumab (Cyramza), may be used with chemotherapy or alone if other treatments have stopped working. It works by blocking the formation of new blood vessels that tumors need to grow. Additional targeted drugs like zolbetuximab may be used for HER2-negative stomach cancer in combination with chemotherapy.[7]
Immunotherapy
Immunotherapy drugs help the body’s own immune system recognize and attack cancer cells. These treatments have shown promise in advanced gastric cancer. Drugs like nivolumab (Opdivo) and pembrolizumab (Keytruda) may be used with chemotherapy to treat advanced or metastatic stomach cancer. These drugs work by blocking proteins that prevent immune cells from attacking cancer, essentially taking the brakes off the immune system.[7]
Not all patients respond to immunotherapy, and doctors may perform specific tests to determine who is most likely to benefit. These tests look for markers like PD-1 or other biomarkers that predict response to treatment. Immunotherapy can have unique side effects related to an overactive immune system, such as inflammation of various organs, which require careful monitoring.[10]
Surgery
Surgery for stage IV gastric cancer is typically performed to relieve symptoms rather than to cure the disease. This is called palliative surgery. For example, a subtotal gastrectomy (removal of part of the stomach) may be done to remove areas that are causing bleeding or pain. If a tumor is blocking the passage of food, doctors might place a stent, which is a hollow tube that holds the passage open and allows food to pass through more easily.[7]
In cases where the stomach tumor causes a complete blockage that cannot be relieved by stenting or other methods, a feeding tube may be placed. This tube delivers liquid nutrition directly into the stomach or small intestine, ensuring the patient can receive adequate nutrition even when eating normally is not possible. Surgery might also be needed if the cancer causes a bowel obstruction, where part of the intestine is blocked and needs to be removed or bypassed.[7]
Radiation Therapy
External radiation therapy may be offered for stage IV stomach cancer, either alone or in combination with chemotherapy (a combination called chemoradiation). Giving chemotherapy at the same time as radiation can sometimes make the radiation work better. Radiation therapy is particularly useful for relieving specific symptoms caused by the cancer, such as bleeding, pain, difficulty swallowing, or blockages. It uses high-energy beams to destroy cancer cells in targeted areas.[7]
Laser Therapy and Endoscopic Procedures
For some patients, less invasive procedures can help manage symptoms. Laser therapy can be used to destroy tumors, stop bleeding, or relieve blockages in the stomach. This can sometimes be done without open surgery by using an endoscope, which is a long, flexible tube inserted down the throat and into the stomach. The laser beam is delivered through the endoscope to treat the affected area. This procedure is also called endoscopic tumor ablation.[4]
Living With Advanced Gastric Cancer
Living with stage IV gastric cancer requires significant adjustments to daily life. Because the stomach plays such an important role in digestion and nutrition, advanced stomach cancer can greatly impact a person’s relationship with food. Patients may need to eat smaller amounts more frequently, or make changes to what they eat. They might need to stay upright for some time after eating to help with digestion. Working with a dietitian or nutritionist can help ensure adequate nutrition despite these challenges.[20]
Treatment for advanced cancer typically requires frequent medical appointments. Chemotherapy is usually given every two weeks, and progress is monitored through scans typically every two to three months. Patients often work with a team of specialists including oncologists (cancer doctors), radiologists, surgeons, gastroenterologists, palliative care specialists, and nutritionists. This multi-disciplinary approach ensures all aspects of care are addressed.[20]
Managing symptoms and side effects is an ongoing process. Common symptoms of advanced stomach cancer include pain, difficulty swallowing, nausea, vomiting, weight loss, fatigue, and in some cases, jaundice (yellowing of the skin and eyes) or ascites (fluid buildup in the abdomen). Palliative care specialists can help manage these symptoms through various medications and interventions, significantly improving quality of life.[6]
Prognosis and Survival
The outlook for stage IV gastric cancer varies greatly among patients. Survival statistics provide general information based on large groups of people but cannot predict what will happen to any individual patient. Many factors influence prognosis including the patient’s age and overall health, the specific characteristics of the cancer, how well it responds to treatment, and where exactly the cancer has spread.[19]
In England, statistics show that around 20 out of 100 people (about 20%) with stage IV stomach cancer survive for 1 year or more after diagnosis. It’s important to understand that these are averages and some people live longer than these statistics suggest. Five-year survival data for stage IV disease is limited because unfortunately most patients do not survive that long, but the statistics that do exist show that continuous improvements in treatment are gradually extending survival times.[19]
For patients with stage IV gastric cancer in Japan and Korea, where treatment protocols are well-established and stomach cancer is more common (meaning doctors have more experience treating it), five-year survival rates have been reported at 15.3% and 18% respectively. While these numbers may seem discouraging, they represent averages across all stage IV patients, and individual outcomes can be better, especially for those who respond well to treatment.[8]
Several factors can influence prognosis. Patients with good performance status (meaning they are able to carry out daily activities with minimal difficulty) tend to do better than those who are bedridden or require significant assistance. Younger patients generally have better outcomes than older patients, though age alone is not the determining factor. The specific location and extent of metastases also matter—for example, patients with cancer spread limited to nearby lymph nodes may have better outcomes than those with widespread liver metastases.[8]
The Role of Clinical Trials
For some people with stage IV gastric cancer, participating in a clinical trial may be an important option to consider. Clinical trials test new cancer drugs, new combinations of existing drugs, or entirely new approaches to treatment. These studies are carefully designed to answer specific questions about how well a treatment works and what side effects it causes. Some trials compare a new treatment to the current standard treatment to see if the new approach is better.[10]
Participating in a clinical trial gives patients access to cutting-edge treatments that are not yet widely available. It also contributes to medical knowledge that may help future patients with gastric cancer. However, clinical trials are not right for everyone, and there may be additional requirements or more frequent monitoring involved. Patients interested in clinical trials should discuss this option with their oncologist, who can help determine if there are appropriate trials available and whether enrollment would be beneficial.[10]
When Treatment May Not Be the Right Choice
There may come a time when cancer treatments are no longer working effectively, are unlikely to improve the situation, or cause side effects that are too difficult to cope with. In such cases, some patients may decide they do not want further cancer treatment. This is a deeply personal decision that should be made after careful discussion with healthcare providers and loved ones.[7]
Choosing not to have cancer treatment does not mean giving up on care. Palliative care continues to focus on making patients as comfortable as possible, managing pain and other symptoms, and providing emotional and spiritual support. Hospice care, which is specialized care for people in the final months of life, can provide comprehensive support for both patients and their families. These services ensure dignity, comfort, and quality of life are maintained regardless of treatment decisions.[7]
