Gastric cancer, also known as stomach cancer, originates in the cells lining the stomach. To understand its progression, medical professionals use a staging system that classifies the cancer based on how far it has grown and spread. Staging provides a common language for doctors to determine the extent of the disease and create an appropriate treatment plan. The most advanced form is designated as stage 4.
Understanding Stage 4 Gastric Cancer
Stage 4 gastric cancer signifies the disease has spread beyond the stomach, a process called metastasis. During metastasis, cancer cells travel through the bloodstream or lymph system to establish new tumors in distant parts of the body. This stage is also referred to as advanced or metastatic stomach cancer.
The most common sites for metastasis are the liver, lungs, and the peritoneum, which is the membrane lining the abdominal cavity. Distant lymph nodes are also a frequent site of spread. The specific locations of these new tumors are a defining characteristic of a stage 4 diagnosis and influence how the disease is managed.
Stage 4 is determined through imaging tests, lab results, and sometimes tissue examination. Doctors use the TNM staging system, which evaluates the primary tumor (T), spread to nearby lymph nodes (N), and the presence of distant metastasis (M). In the TNM system, any cancer with evidence of distant spread (M1) is classified as stage 4.
Symptoms and Complications
A common complication of stage 4 gastric cancer is ascites, a buildup of fluid in the abdomen that can cause swelling, discomfort, and shortness of breath. Severe and persistent pain in the stomach area is also a frequent experience for individuals with advanced disease.
If the cancer has metastasized to the liver, it can cause jaundice, a condition that leads to the yellowing of the skin and eyes. Significant, unintentional weight loss is another common symptom, often accompanied by a loss of appetite and a feeling of fullness after eating very little.
Blockages in the digestive tract are a serious complication. A growing tumor may obstruct the passage of food from the esophagus into the stomach or from the stomach into the small intestine, leading to difficulty swallowing (dysphagia). This can also cause nausea, vomiting, and in some cases, bleeding within the stomach that may result in bloody stools.
Treatment Approaches
The primary goal of treating stage 4 gastric cancer is not to cure the disease, but to slow its progression, manage symptoms, and extend life. Treatment plans are highly individualized based on the patient’s overall health and the cancer’s characteristics. A combination of therapies is often used and may be adjusted over time.
Chemotherapy is a foundational treatment for advanced stomach cancer. These drugs travel through the bloodstream to destroy cancer cells throughout the body, helping to shrink tumors and control growth. Common chemotherapy agents include fluorouracil and capecitabine.
Targeted therapy attacks specific vulnerabilities in cancer cells. For example, trastuzumab is used for HER2-positive stomach cancers, which produce an excess of the HER2 protein. Other targeted drugs, like ramucirumab, block the growth of new blood vessels that tumors need to survive.
Immunotherapy helps the body’s immune system fight cancer, and drugs like pembrolizumab may be used. Radiation therapy is used more selectively. It can be directed at specific tumors to shrink them, which can help relieve pain, stop bleeding, or reduce a blockage.
Palliative Care and Symptom Management
Palliative care is a specialized area of medicine focused on providing relief from the symptoms and stress of a serious illness. Its aim is to improve quality of life and it can be provided at any point during treatment, alongside therapies meant to control the cancer.
A central component of palliative care is effective pain control, using a managed plan of medications and other techniques to manage discomfort. Nutritional support is also important, as a nutritionist can devise a diet that is easier to tolerate. If a blockage prevents normal eating, a stent or feeding tube may be necessary.
Palliative care also addresses complications like ascites, where a procedure called paracentesis can drain excess abdominal fluid. Managing the side effects of cancer treatments, such as nausea and fatigue from chemotherapy, is another focus. This care extends to providing emotional and psychological support for both patients and their families.
Prognosis and Life Expectancy
The prognosis for stage 4 gastric cancer is a statistical measure of outcomes for a large group and is not predictive for any single individual. The most common statistic is the five-year relative survival rate. This rate compares people with the same type and stage of cancer to the general population.
For stage 4 stomach cancer, the five-year relative survival rate is approximately 5-7%. This means that people diagnosed with this stage of cancer are, on average, about 5-7% as likely as those without the cancer to live for at least five years after diagnosis.
An individual’s personal outlook can vary based on several factors, including:
- Age and overall health, which affect tolerance for the cancer and its treatments.
- The specific locations where the cancer has spread.
- The type of treatment a person receives.
- How well the cancer responds to therapies like chemotherapy or targeted drugs.