Stomach cancer, also known as gastric cancer, usually starts in the mucus-producing cells that line the stomach. This type of cancer is known as adenocarcinoma.
For the past few decades, rates of cancer in the main part of the stomach been falling worldwide. However, during the same period, cancer in the area where the top part of the stomach (cardia) meets the lower end of the swallowing tube (esophagus) has become more common. This area of the stomach is known as gastroesophageal junction.
Gastric cancer is the seventh most common cancer among females and fifth most common cancer among males in India.
Types of stomach cancer
- Lymphoma – These are cancers of the immune system tissue that are found in the wall of the stomach. The outlook and treatment depend on the type of lymphoma.
- Gastrointestinal stromal tumor (GIST) – These rare tumors begin in very early forms of cells in the wall of the stomach called interstitial cells of Cajal. Some of these tumors are non-cancerous (benign); although others are cancerous. Although GISTs can be found anywhere in the digestive tract, they are mostly found in the stomach.
- Adenocarcinoma – About 90-95% of cancers of the stomach are adenocarcinomas. These cancers begin from the cells that form the innermost lining of the stomach – the mucosa.
- Carcinoid tumor – These tumors begin in the hormone-making cells of the stomach. Most of these tumors do not spread to the other body organs.
- Other cancers – Some other types of cancer, such as small cell carcinoma, squamous cell carcinoma, and leiomyosarcoma can also begin in the stomach, but these cancers are very rare.
Very early on, stomach cancer can cause:
- Feeling bloated after you have a meal
- Slight nausea
- Loss of appetite
However, just having heartburn or indigestion after a meal does not mean you have cancer. But in case you feel these symptoms a lot, talk to a doctor. As stomach tumors grow, you may experience more serious symptoms, like:
- Stomach pain
- Blood in your stool
- Stomach pain
- Weight loss for no reason
- Trouble swallowing
- Yellowish skin or eyes
- Swelling in the stomach
- Diarrhea or constipation
- Weakness or feeling tired
Causes and diagnosis
Gastroesophageal junction cancer is usually associated with having gastrointestinal reflux disease (GERD) and, less strongly, with smoking and obesity. GERD is a disease caused by frequent backflow of stomach acid into the esophagus.
Studies have proven that there is a strong correlation between a diet high in salted and smoked foods and stomach cancer located in main part of the stomach. As the use of refrigeration for preserving foods has increased around the globe, the rates of stomach cancer have declined gradually.
Tests used to diagnose stomach cancer and gastroesophageal junction cancer include:
- Imaging tests – These tests are used to look for stomach cancer which include computerized tomography scans and a special type of x-ray exam called a barium swallow.
- A tiny camera to see inside the stomach (upper endoscopy) – A thin tube containing a tiny camera is passed down the throat and into the stomach. The doctor can look for signs of stomach cancer. If any suspicious areas are found, a piece of tissue can be collected for analysis which is known as biopsy.
Determining the stage of stomach cancer
The stage of the stomach cancer helps the doctor decide which treatments may be best for you. Tests used to determine the stage of cancer include:
- Imaging tests – Tests may include positron emission tomography (PET) and CT.
- Exploratory surgery – The doctor may recommend surgery to look for signs that the cancer has spread beyond your esophagus or stomach, within the abdomen or chest. Exploratory surgery is mostly done laparoscopically. It means the surgeon makes several small incisions in the abdomen and inserts a special camera that transmits images to a monitor in the operating room.
Stages and treatment options
The stages of adenocarcinoma of the stomach include:
- Stage 1 – The tumor is limited to the top layer of tissue that lines the inside of the stomach. Cancer cells also may have spread to a limited number of the nearby lymph nodes.
- Stage 2 – The cancer has spread deeper, growing into a deeper muscle layer of the stomach wall. Cancer may also have spread to a more number of lymph nodes.
- Stage 3 – The cancer may have grown through all the layers of the stomach and spread to the nearby structures; or it may be a smaller cancer that has spread more extensively to the lymph nodes.
- Stage 4 – The cancer has spread to the distant areas of the body.
The treatment options for stomach cancer or gastroesophageal junction cancer depend on the stage of the cancer, the overall health and personal preferences:
- Surgery – Gastroesophageal junction cancer which has not spread requires surgery to remove the part of the stomach where the tumor is located. The aim of the surgery is to remove all of the cancer and a margin of healthy tissue, when possible. The nearby lymph nodes are generally removed as well. Some of the options include:
- Removing early-stage tumors from the stomach lining
- Removing a portion of the stomach (subtotal gastrectomy) – Gastrectomy means the removal of part or all of the stomach.
- Removing the entire stomach (total gastrectomy)
- Removing lymph nodes to look for cancer
- Surgery to relieve signs and symptoms
- Radiation therapy – It uses high-powered beams of energy such as protons and x-rays to destroy cancer cells. In gastroesophageal junction cancer, radiation therapy can be used before surgery to shrink a tumor so that it is more easily removed. It can also be used after surgery to kill any cancer cells that might remain in the area around the stomach.
- Chemotherapy – It is a drug treatment that uses chemicals to kill cancer cells. It is often combined with radiation therapy. Chemotherapy may be used in people with advanced stomach cancer in order to relieve any symptoms and signs.
- Targeted drugs – Targeted therapy uses drugs which attack specific abnormalities within cancer cells. These drugs are often used in combination with chemotherapy drugs.
Side effects of treatment
Chemotherapy, surgery, radiation therapy and other forms of stomach cancer treatment may sometimes cause physical side effects. However, these vary from patient to patient depending on their overall health and specific type of treatment, though some commonly reported side effects include:
- Nausea and vomiting
- Changes in appetite
Survivorship and Prevention of Stomach Cancer
The journey for a person with gastroesophageal junction cancer or stomach cancer doesn’t end when the treatment is completed. Women and men can often face a range of physical, emotional and mental challenges, making the quality of life after treatment all the more important. Managing the above discussed effects as they arise and anticipating them before they become an issue is an important aspect of survivorship. Depression and anxiety are other major issues for stomach cancer survivors, as is the struggle to return to a ‘regular’ life.
To help survivors cope with such challenges, it is advised to communicate with survivors’ care teams. It is also important to have a solid support system so you can share whatever you might be experiencing after the treatment. Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious disease. Palliative care specialists work with you, your family and the other doctors to provide an extra layer of support that complements your ongoing care and support. When palliative care is used along with all of the other treatments, people with cancer may feel better and survive longer.
It is not clear what causes gastroesophageal junction or stomach cancer, hence there is no way to prevent it. But you can take steps to reduce your risk making small changes to your everyday life. For example:
- Exercise – Regular exercise is associated with a reduced risk of stomach or gastroesophageal junction cancer. Try to fit physical activity into the day most days of the week.
- Reduce the amount of smoked and salty foods you eat – Protect the stomach by limiting these foods.
- Eat more fruits and vegetables – Incorporate more fruits and vegetables into your diet every day.
- Stop smoking – Smoking increases the risk of stomach cancer, as well as many other types of cancer.
- Ask the doctor about your risk of gastroesophageal junction or stomach cancer – Discuss with a doctor if you have an increased risk of gastroesophageal junction cancer or stomach cancer. He may then consider periodic endoscopy to look for signs of stomach cancer.