The treatment goals and options for stomach cancer vary depending on how advanced the cancer is and how far it has spread. Surgery is often an effective treatment option for people with early-stage stomach cancer. Other treatments may include chemotherapy, radiation therapy, and immunotherapy.

An oncologist (a medical doctor specializing in the diagnosis and treatment of cancer) will determine your cancer stage before developing a treatment plan. Cancer staging is the process of determining how advanced a cancer is. The stage depends on how large a cancerous tumor is and how far cancer cells have spread throughout the body. In general, the higher the stage, the more advanced the cancer is. 

Stomach cancer staging uses the layers of the stomach wall to determine how far cancer cells have spread. Cancer usually begins in the innermost layer called the mucosa. From there, the cancer moves to the other layers of the stomach wall, including the submucosa, muscularis propria, subserosa, and serosa. 

Stomach cancer treatment depends on the stage: 

• Very early stage: Cancer cells are present in the inner lining layer of the stomach (mucosa) but have not grown into the outer layers of the stomach wall. Surgery is usually the recommended treatment. 
• Potentially resectable (surgical removal): Cancer cells have spread to other layers of the stomach wall. Treatment usually includes surgery, followed by lymph node removal and possible chemotherapy or radiation therapy. 
• Unresectable (can’t surgically remove) local or regional: Cancer cells haven’t spread to distant areas of the body, but can’t be entirely surgically removed because they’ve invaded to nearby lymph nodes or organs. Treatment may include chemotherapy, immunotherapy, and radiation therapy. 
• Metastatic: Cancer cells have spread to distant areas of the body, such as the bones or lungs. This stage is difficult to treat. Treatment usually focuses on measures to relieve symptoms and improve quality of life. 

Treatments for Very Early-Stage Stomach Cancer

Surgery is the recommended treatment option for very early-stage stomach cancer. The goal of surgery in this stage is to completely remove the cancerous tumor and achieve remission. Surgery offers the best chance of long-term survival for people with early-stage stomach cancer. 

Surgical options for very early-stage stomach cancer include:

• Endoscopic resection: The surgeon passes a flexible tube called an endoscope down the throat and into the stomach to remove the tumor and normal tissue around it. 
• Subtotal (partial) gastrectomy: The surgeon makes a small incision to remove part of the stomach that contains the tumor. 
• Total gastrectomy: The surgeon removes the entire stomach and nearby lymph nodes. They may also remove nearby organs, including the spleen or parts of the esophagus, intestine, or pancreas. This type of surgery is often recommended when the cancer has spread throughout the stomach. 
• Lymph node removal: When removing part or all of the stomach, the surgeon removes the nearby lymph nodes to ensure that all of the cancer cells are gone.

Treatments for Potentially Resectable Stomach Cancer

People with potentially resectable stomach cancer have a cancerous tumor that has grown into more layers of the stomach lining or wall. Treatment may include surgery with chemotherapy or radiation therapy.

Chemotherapy

Chemotherapy is medication that kills cancer cells. Your doctor may recommend chemotherapy before surgery to shrink the tumor, known as neoadjuvant treatment, as well as chemotherapy after surgery to ensure that all of the cancer cells have been removed. 

Possible side effects of chemotherapy include:

Radiation Therapy

People with potentially resectable stomach cancer may also benefit from radiation therapy. Radiation therapy administers high-dose energy beams to kill cancer cells. Your treatment team may recommend radiation before surgery to shrink the tumor or after surgery to kill any remaining cancer cells. Radiation can be given with or without chemotherapy. 

Possible side effects of radiation therapy include skin redness, rash, or dryness, nausea, vomiting, diarrhea, and fatigue.

Treatments for Unresectable Local or Regional Stomach Cancer

If your doctor says you have unresectable stomach cancer, it means your tumor can’t be fully removed with surgery. Local or regional cancer means that the cancer cells have spread to nearby areas of the body, such as the lymph nodes or close organs. 

While surgery can’t cure your cancer, your team may recommend palliative (pain management) surgery to improve your symptoms and quality of life. 

Palliative surgical options may include:

• Gastric bypass (gastrojejunostomy): The surgeon attaches part of the small intestine to the upper part of the stomach. Your care team may recommend this surgery if you have a large tumor that blocks food from leaving the stomach. 
• Subtotal gastrectomy: The surgeon removes the part of the stomach that contains the tumor to help lower the risk of bleeding, pain, and other complications. 
• Feeding tube placement: The doctor places a feeding tube through the skin of the abdomen into the lower part of the stomach. This may be helpful if you are unable to eat. 
• Endoscopy procedures: The doctor places a flexible tube called an endoscope down your esophagus and into your stomach to treat the tumor. This may be helpful for people who are not healthy enough for major surgery. 

Any surgery comes with risks. Many people experience side effects such as nausea, heartburn, diarrhea, and abdominal pain after surgery. Having surgery for stomach cancer may cause bleeding, blood clots, organ damage, and infection

In addition to surgery, you may also benefit from chemotherapy and radiation therapy.

Treatments for Metastatic Stomach Cancer

Metastatic stomach cancer refers to stomach cancer that has spread to other areas of the body, such as the bones or lungs. This is the most advanced type of cancer and is often challenging to treat. 

Your doctor will likely recommend a combination of palliative surgery, chemotherapy, radiation therapy, and immunotherapy. Immunotherapy boosts the body’s immune response to cancer. One type of immunotherapy called immune checkpoint inhibitors works by helping the immune cells recognize and kill cancer cells. 

Immune checkpoint inhibitors used to treat advanced stomach cancer are given intravenously (IV), or by vein, and are often given with chemotherapy. 

Immunotherapy may cause the following side effects:

• Fever
• Fatigue
• Weakness
• Cough 
• Nausea
• Diarrhea or constipation 
• Skin itching or rashes
• Loss of appetite 
• Muscle or joint aches 
• Shortness of breath 

The prognosis and life expectancy for stomach cancer depend on several factors, including the cancer’s type and stage. Your age and overall health also affect your prognosis. 

Here are the five-year survival rates for the different stages of stomach cancer: 

• Localized stomach cancer: 75%
• Regional stomach cancer: 35%
• Distant or metastatic stomach cancer: 7%

Receiving a stomach cancer diagnosis is overwhelming, and you may be feeling many emotions. Even after completing your treatment plan, you may continue to deal with stomach cancer and its complications. 

Talk with your healthcare team about the following aspects of your treatment management: 

• Follow-up appointments: After completing your treatment, your team will continue to run tests, including blood tests and imaging studies. Report any new symptoms or side effects to your doctors right away. 
• Dumping syndrome: Many people with stomach cancer experience dumping syndrome after treatment. This syndrome causes nausea, diarrhea, sweating, and flushing after eating. There are treatment options available. 
• Nutrition support: Stomach cancer and its treatments affect how your body consumes and absorbs nutrients from food. You may lose your appetite and need to eat only small meals throughout the day. Consider meeting with a dietitian for support. Your care team may recommend taking nutritional supplements, especially if part of your stomach was removed during treatment. 
• Healthful lifestyle: Work with a dietician to develop a nutritious diet rich in fresh fruits and vegetables. Aim to be physically active every day, and maintain a weight you and your doctor decide is optimal for you. Avoid all tobacco products, and talk with your medical team before trying alcohol.