Stomach (Gastric) Cancer Diagnosis & Treatment

What are the Stomach Cancer Treatments Available?

Presenting treatments for stomach cancer in adults

Stomach cancer, also known as gastric cancer, may be treated with surgery, radiation therapy, chemotherapy, targeted therapy, or immunotherapy.

Treatment options and recommendations depend on several factors, including the type and stage of cancer, possible side effects, and the patient’s preferences and overall health. Often, a combination of treatments is used to treat gastric cancer.

Descriptions of the common types of treatments used for stomach cancer are listed below.

Surgical treatment involves the removal of the tumour and some surrounding healthy tissue during an operation. The type of surgery used depends on the stage of the cancer.

Endoscopic mucosal resection: This is a procedure that may be used to treat very early-stage cancers, when the tumour has not grown deeply into the stomach wall and the chance of spread outside the stomach is very low.
Subtotal or partial gastrectomy: In early stages when the cancer is localised in the stomach, surgery is used to remove the part of the stomach with the cancer and its surrounding lymph nodes. This is called a subtotal or partial gastrectomy. In a partial gastrectomy, the surgeon connects the remaining part of the stomach to the esophagus or small intestine.
Total gastrectomy: This surgery is done if the cancer has spread widely in the stomach. It is also often advised if the cancer is in the upper part of the stomach or near the esophagus. A total gastrectomy is the removal of the entire stomach. During a total gastrectomy, the surgeon attaches the esophagus directly to the small intestine.
Lymphadenectomy: Surrounding lymph nodes are often removed during surgery because the cancer may have spread to involve those lymph nodes. This is called a lymphadenectomy or lymph node dissection.
Gastric bypass: Gastric bypass or gastrojejunostomy is a procedure when the tumour in the lower part of the stomach has grown large enough to obstruct food from exiting the stomach. The treatment to bypass the lower part of the stomach is done by attaching part of the intestine (the jejunum) to the upper part of the stomach, allowing food to transit from the stomach through the new connection.

Radiation therapy is a stomach cancer treatment involving the use of high-energy rays to destroy cancer cells. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Patients with gastric cancer usually receive external beam therapy (EBRT) which focuses radiation on the cancer. Other special types of radiation therapy, such three-dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT) are also used in treating gastric cancer. These newer approaches aim the radiation at the cancer from several angles. This helps to focus the radiation on the cancer and limit the damage to nearby normal tissues.

Radiation therapy may be used before the surgery to shrink the size of the tumour and after the surgery to destroy any remaining cancer cells. It may also be used to alleviate cancer related symptoms of pain or bleeding in patients with advanced gastric cancer.

Chemotherapy treatment involves the use of medications to destroy cancer cells, usually by stopping the cancer cells from growing, dividing, or multiplying.

A chemotherapy regimen, or schedule, usually consists of a specific number of cycles given over a set period of time. A patient may receive one (1) drug at a time, or a combination of different drugs given at the same time.

The goal of chemotherapy is to destroy cancer cells before or after surgery, slow the tumour’s growth, or alleviate cancer-related symptoms. Chemotherapy may be administered in combination with radiation therapy in certain cases. Most chemotherapy treatments for stomach cancer are based on combinations of the following drugs:

Cisplatin
Oxaliplatin
Fluorouracil

Other drugs used may include:

Capecitabine
Docetaxel
Epirubicin
Irinotecan
Paclitaxel
Tegafur/gimeracil/oteracil

Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. This type of treatment blocks the growth and spread of cancer cells with limited damage to healthy cells.

To tailor the most effective treatment for each patient, the doctor may order some tests to identify the genes, proteins, and other factors in a patient’s tumour. Targeted therapy for stomach cancer includes:

HER2-targeted therapy: Some cancers may overexpress a protein known as the human epidermal growth factor receptor 2 (HER2). This type of cancer is called “HER2-positive cancer”. Trastuzumab plus chemotherapy may be an option for people with advanced stage HER2-positive gastric cancer.
Anti-angiogenesis therapy: Anti-angiogenesis therapy is focused on limiting angiogenesis, which is the formation of new blood vessels. As a tumour requires nutrients to be delivered by blood vessels for growth, the goal of anti-angiogenesis therapies is to “starve” the tumour. For patients whose tumour has grown while receiving initial chemotherapy, an anti-angiogenesis medication, ramucirumab would be an additional option.

Immunotherapy is designed to boost the body’s natural defenses to fight the cancer. Checkpoint inhibitor is a form of immunotherapy used to treat stomach cancer.

PD-1 Inhibitors: A form of immunotherapy treatment is PD-1 inhibitor. Pembrolizumab and Nivolumab are drugs that targets PD-1, a checkpoint protein on immune system cells called T cells,that normally helps keep these cells from attacking normal cells in the body. By blocking PD-1, this drug boosts the immune response against gastric cancer cells. It can also shrink some tumours or slow their growth.

Are there any Side Effects of Stomach Cancer Treatment?

Surgery for stomach cancer is complex and may have complications. Like all cancer treatments, surgery has benefits, risks, and side effects. After surgery, it is common to have some pain from the surgery’s effect on the body. Most patients will have at least some pain after the operation, which can usually be helped with pain medication, if needed.

Side effects after surgery may include nausea, heartburn, abdominal pain and diarrhea. Fatigue is also common after surgery. Many people are very tired after major surgery, especially when it involves the abdomen in the case of gastric cancer. Fatigue usually goes away gradually two to four weeks after surgery.

The possible side effects of radiation therapy depend on where the radiation is targeted. The common side effects of this stomach cancer treatment include:

Skin irritation
Fatigue
Nausea
Diarrhea
Lower blood cell counts
Mouth and gum sores/difficulty swallowing/dry mouth
A type of swelling called lymphedema

The side effects of chemotherapy as a stomach cancer treatment commonly include the following:

Nausea and vomiting
Fatigue
Diarrhea
Tiredness
Loss of appetite
Hair loss
Skin and nail changes
Numbness and tingling
Swelling
Low white blood counts, low red blood counts and low platelet counts
Risk of infections
Risk of infertility

Depending on the targeted drugs used for this stomach cancer treatment, the common side effects of targeted therapy may include:

High blood pressure
Low white blood counts, low red blood counts and low platelet counts
Blood clots
Fatigue
Nausea and vomiting
Diarrhea
Poor appetite and weight loss
Skin rash/Mouth sores
Cardiotoxicity
Thyroid disorder

The side effects of immunotherapy as stomach cancer treatment may include:

Nausea and vomiting
Diarrhea
Rash and other skin changes
Itch
Vision problems
Muscle or joint pain
Loss of appetite
Cough and Shortness of breath
Thyroid disorder

What do I need to do if I have Stomach Cancer?

If you suspect that you or your loved one have stomach cancer, it is advisable to get the support you need as soon as possible. Early detection and diagnosis of stomach cancer is key to treating the disease.

Regardless of what stage your stomach cancer may be, you should schedule an appointment to see an oncologist specialising in stomach cancer as soon as possible. With the speed of developments in gastric cancer diagnosis and treatment, novel emerging treatment options could be explored by your oncologist.

What is Stomach Cancer (Gastric Cancer)?

Definition of Gastric Cancer

The stomach is located in the upper abdomen and plays a central role in digesting food. When food is swallowed, it is pushed down the muscular tube called the esophagus, which connects the throat with the stomach. Then, the food enters the stomach. The stomach mixes the food and releases gastric juices that help break down and digest the food. The food then moves into the small intestine for further digestion.

Stomach cancer, also called gastric cancer, begins when healthy cells in the stomach become abnormal and grow out of control into a tumour. A tumour can be cancerous or benign. A cancerous tumour is malignant, meaning it can grow and spread to other parts of the body. Cancer can begin in any part of the stomach. It can also spread to nearby lymph nodes and other parts of the body, such as the liver, peritoneum, lungs and bones.

Most gastric cancers arise from the glandular cells lining the inside of the stomach and are known as adenocarcinoma. Other types of cancerous tumours that form in the stomach include lymphoma, gastrointestinal stromal tumour (GIST), and neuroendocrine tumours, but these are rare.

In Malaysia, gastric cancer is the 9th most common cancer in male. About 1,000 new gastric cancers are diagnosed in male patients each year.

Globally, stomach (gastric) cancer is the fifth (5th) most common cancers contributing to more than one (1) million cases per year and 5.7% of all cancer diagnosis.

What are the Signs and Symptoms of Stomach Cancer?

The most common symptoms of Stomach Cancer are:

Gastric cancer is usually not found at an early stage because it often does not cause specific symptoms. When symptoms do occur, they may be vague and may include those listed below.

Indigestion or heartburn
Pain or discomfort in the abdomen
Nausea and vomiting, particularly vomiting up solid food shortly after eating
Diarrhea or constipation
Bloating of the stomach after meals
Loss of appetite
Sensation of food getting stuck in the throat while eating

Symptoms of advanced gastric cancer may include:

Weakness and fatigue
Vomiting blood or having blood in the stool
Unexplained weight loss

Screening for Stomach Cancer

Screening is used to look for cancer before you have any symptoms or signs.

Stomach (gastric) cancer is usually found when a patient goes to the doctor because of signs or symptoms they are having. If gastric cancer is suspected, exams and tests will be needed to find out for sure. If cancer is found, other tests might then be needed to learn more about it.

Gastric Cancer screening tests include:

Upper endoscopy, or also called oesophagogastroduodenoscopy (OGD) is the test most often done if the doctor suspects a patient to have gastric cancer.

During this test, the doctor passes an endoscope, which is a thin, flexible, lighted tube with a small video camera on the end, down the patient’s throat. This lets the doctor see the inner lining of the esophagus, stomach, and first part of the small intestine. If abnormal areas are seen, biopsy samples can be removed using instruments passed through the endoscope. The tissue samples are sent to a lab, where they are looked at with a microscope to see if they contain cancer.

How Stomach Cancer is Diagnosed

Doctors use many tests to find or diagnose stomach cancer. They also do tests to learn if cancer has spread to another part of the body from where it started. If this happens, it is called metastasis. For example, imaging tests can show if the cancer has spread.

The doctor may consider these factors when choosing a diagnostic test:

The type of cancer suspected
Patient’s signs and symptoms
Patient’s age and general health
The results of earlier medical tests

Tests to diagnose Stomach Cancer include:

Medical history and physical exam: When taking the medical history, the doctor will ask the patient about their symptoms (such as eating problems, pain, and bloating) to see if they may suggest stomach cancer or another cause. The physical exam can give the doctors information about possible signs of stomach cancer.
Biopsy: This is the removal of a small amount of tissue for examination under a microscope.
Molecular testing of the tumour: The doctor may recommend running laboratory tests on a tumour sample to identify specific genes, proteins, and other factors unique to the tumour. Results of these tests can help determine a patient’s treatment options. For gastric cancer, testing may be done for PD-L1 and high microsatellite instability (MSI-H), which may also be called a mismatch repair deficiency. Testing can also be done to determine if the tumour is making too much of a protein called human epidermal growth factor receptor 2 (HER2), particularly if the cancer is more advanced. The results of these tests help doctors find out if immunotherapy is a treatment option.
Endoscopy: This test allows the doctor to see the inside of the body with a thin, lighted, flexible tube called a gastroscope or endoscope. The patient may be sedated as the tube is inserted through the mouth, down the esophagus, and into the stomach and small bowel. The doctor can remove a sample of tissue as a biopsy during an endoscopy and check it for signs of cancer.
Endoscopic ultrasound: This test is similar to an endoscopy, but the gastroscope has a small ultrasound probe on the end. An ultrasound image of the stomach wall helps doctors determine how far the cancer has spread into the stomach and nearby lymph nodes, tissue, and organs, such as the liver or adrenal glands.
Barium swallow: In a barium swallow, a patient swallows a liquid containing barium, and a series of x-rays are taken. Barium coats the lining of the esophagus, stomach, and intestines, so tumours or other abnormalities are easier to see on the x-ray.
Computed tomography (CT or CAT) scan: A CT scantakes pictures of the inside of the body using x-rays taken from different angles. A CT scan allows a better understanding of the location of the tumour and if it has spread to other sites.
Magnetic resonance imaging (MRI): An MRI uses magnetic fields to produce detailed images of the body. MRI can be used to measure the tumour’s size.
Positron emission tomography PET/CT scan: A PET/CT scan is a sensitive scan which uses a small amount of a radioactive sugar substance as a dye to pick up the location of the tumour and assess for other sites of cancer.
Laparoscopy: This is a minor surgery in which the surgeon inserts a thin, lighted, flexible tube called a laparoscope into the abdominal cavity. It is used to find out if the cancer has spread to the lining of the abdominal cavity or liver.

What are the Causes and Risk Factors of Stomach Cancer?

The following factors may raise a person’s risk of developing stomach (gastric) cancer:

Age: Stomach cancer occurs most commonly in patients older than 55. Most patients diagnosed with stomach cancer are in their 60s and 70s.
Gender: Men are twice as likely to develop stomach cancer as women.
Bacteria: A common bacterium called Helicobacter pylori, also called H. pylori, causes gastric inflammation and ulcers. It is also considered one of the main causes of stomach cancer. Testing for H. pylori is available, and an infection can be treated with antibiotics. Testing for H. pylori is recommended if you have had a first-degree relative, such as a parent, sibling, or child, who has been diagnosed with stomach cancer or an H. pylori infection. Other family members could have it as well, and the infection should be treated if found.
Family history (Genetics): Patients who have a parent, child, or sibling who has had stomach cancer have a higher risk of the disease. In addition, certain inherited genetic disorders, such as hereditary diffuse stomach cancer, Lynch syndrome, hereditary breast and ovarian cancer (HBOC), and familial adenomatous polyposis (FAP) may increase the risk of stomach cancer.
Ethnicity: Stomach cancer is more common in Asians
Diet: Eating a diet high in salt has been linked to an increased risk of stomach cancer.
Previous surgery or health conditions: Patients who have had stomach surgery, pernicious anemia (Vitamin B12 deficiency), or achlorhydria have a higher risk of stomach cancer.
Occupational exposure: Exposures to certain dusts and fumes may increase the risk of developing stomach cancer.
Tobacco and alcohol: Smoking and alcohol abuse may increase the risk of developing stomach cancer.
Obesity: Excess body weight may increase a patient’s risk of developing stomach cancer.

What are the Types of Stomach Cancer?

The type of stomach cancer a patient has tells what type of cell it started in. These are the several types of cancers that can occur in the stomach:

Adenocarcinomas: Most cancers of the stomach are adenocarcinomas. These cancers develop from the gland cells in the innermost lining of the stomach (mucosa). There are two (2) main types of adenocarcinomas.
Intestinal: The intestinal type tends to have a slightly better prognosis. The cancer cells are more likely to have certain gene changes that might allow for treatment with targeted drug therapy.
Diffuse: The diffuse type tends to grow and spread more quickly. It is less common that the intestinal type and tends to be harder to treat.
Gastrointestinal stromal tumours (GISTs): This rare type of cancer arises from cells in the wall of the stomach called interstitial cells of Cajal. GISTs can start anywhere in the digestive tract, however, most originate from the stomach.
Neuroendocrine tumours (carcinoids): Neuroendocrine tumours (NETs) are also rare. They arise from cells in the stomach (or other parts of the digestive tract) that act like nerve cells in some ways and like hormone-making (endocrine) cells in others. Most NETs tend to grow slowly and do not spread to other organs, but some can grow and spread quickly.
Lymphomas: These cancers arise from the immune system cells known as lymphocytes. Lymphomas usually start in lymph nodes located in other parts of the body, but some can start in the wall of the stomach. The treatment and outlook for these cancers depend on the type of lymphoma and other factors.
Other cancers: Other types of cancer, such as squamous cell carcinomas, small cell carcinomas, and leiomyosarcomas, can also arise from the stomach, but these cancers are very rare.

What are the Stages of Stomach Cancer?

Staging is a way of describing where the cancer is located, or if it has spread and whether it is affecting other parts of the body. The tests and scans used to diagnose the patient’s cancer will give some information about:

the type of cell the cancer started in and where it began
how abnormal the cells look under the microscope (the grade)
the size of the cancer and whether it has spread (the stage)

Stage 0 Gastric Cancer

This is also called carcinoma in situ. The cancer is found only on the surface of the epithelium. The cancer has not grown into any other layers of the stomach. This stage is considered an early cancer (Tis, N0, M0).

Stage 1 Gastric Cancer

Stage IA: The cancer has grown into the inner layer of the wall of the stomach. It has not spread to any lymph nodes or other organs (T1, N0, M0).
Stage IB: Gastric cancer is considered stage IB in either of these 2 conditions:
The cancer has grown into the inner layers of the wall of the stomach. It has spread to 1 to 2 lymph nodes but not elsewhere (T1, N1, M0).
The cancer has grown into the outer muscular layers of the wall of the stomach. It has not spread to the lymph nodes or other organs (T2, N0, M0).

Stage 2 Gastric Cancer

Stage IIA: Gastric cancer is considered stage IIA for any of these conditions:
The cancer has grown into the inner layer of the wall of the stomach. It has spread to 3 to 6 lymph nodes but not elsewhere (T1, N2, M0).
The cancer has grown into the outer muscular layers of the wall of the stomach. It has spread to 1 to 2 lymph nodes but not elsewhere (T2, N1, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has not grown into the peritoneal lining or serosa or spread to any lymph nodes or surrounding organs (T3, N0, M0).
Stage IIB: Gastric cancer is considered stage IIB for any of these conditions:
The cancer has grown into the inner layers of the wall of the stomach. It has spread to 7 to 15 lymph nodes but not elsewhere. (T1, N3a, M0).
The cancer has invaded the outer muscular layers of the wall of the stomach. It has spread to 3 to 6 lymph nodes but not elsewhere (T2, N2, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into the peritoneal lining or serosa. It has spread to 1 to 2 lymph nodes but not elsewhere (T3, N1, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has grown into the peritoneal lining or serosa, but it has not spread to any lymph nodes or surrounding organs (T4a, N0, M0).

Stage 3 Gastric Cancer

Stage IIIA: Gastric Cancer is considered stage IIIA for any of these conditions:
The cancer has grown into the outer muscular layers of the stomach wall. It has spread to 7 to 15 lymph nodes but not to other organs (T2, N3a, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into the peritoneal lining or serosa. It has spread to 3 to 6 lymph nodes but not to other organs (T3, N2, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has grown into the peritoneal lining or serosa and has spread to 1 to 2 lymph nodes but not to other organs (T4a, N1, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach and has grown into nearby organs or structures. It has not spread to any lymph nodes or distant parts of the body (T4b, N0, M0).
Stage IIIB: Gastric cancer is considered stage IIIB for any of these conditions:
The cancer has grown into the inner layer of the wall of the stomach or the outer muscular layers of the stomach wall. It has spread to 16 or more lymph nodes but not to distant parts of the body (T1 or T2, N3b, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into the peritoneal lining or serosa. It has spread to 7 to 15 lymph nodes but has not invaded any surrounding organs (T3, N3a, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach and has grown into the peritoneal lining or serosa. It has spread to 7 to 15 lymph nodes but has not spread elsewhere (T4a, N3a, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach and has grown into nearby organs or structures. It may or may not have spread to 1 to 6 lymph nodes but not to distant parts of the body (T4b, N1 or N2, M0).
Stage IIIC: Gastric cancer is considered stage IIIC for any of these conditions:
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach and may have grown into the peritoneal lining or serosa. It has spread to 16 or more lymph nodes but not to distant parts of the body (T3 or T4a, N3b, M0).
The cancer has grown through all of the layers of the muscle into the connective tissue outside the stomach and has grown into nearby organs or structures. It has spread to 7 or more lymph nodes but not to other parts of the body (T4b, N3a or N3b, M0).

Stage 4 Gastric Cancer

Stage IV: Stage IV gastric cancer describes a cancer of any size that has spread to distant parts of the body in addition to the area around the stomach (any T, any N, M1).

TNM Staging System of Gastic Cancer

This TMN system is commonly used for cancer staging. Results from surgery, diagnostic tests and scans are used to answer these questions:

Tumour (T): How large is the primary tumour? Where is it located?
Node (N): Has the tumour spread into the lymph nodes? If yes, where and how many?
Metastasis (M): Has the cancer spread to other parts of the body? If yes, where and how much?

The results are combined to determine the stage of stomach cancer of each patient and to plan the best treatment.

Tumour (T)

Using the TNM system, the “T” plus a letter or number (0 to 4) is used to describe the how far the tumour has grown into the stomach wall.

Stage may also be divided into smaller groups that help describe the tumour in even more detail. Specific tumour stage information is listed below:

TX: The primary tumour cannot be evaluated.
T0: There is no evidence of a primary tumour in the stomach.
Tis: This stage describes a condition called carcinoma (cancer) in situ. The cancer is found only in cells on the surface of the inner lining of the stomach called the epithelium and has not spread to any other layers of the stomach.
T1: The tumour has grown into the lamina propria, muscularis mucosae, or the submucosa, which are the inner layers of the wall of the stomach.
T1a: The tumour has grown into the lamina propria or muscularis mucosae.
T1b: The tumour has grown into the submucosa.
T2: The tumour has grown into the muscularis propria, the muscle layer of the stomach.
T3: The tumour has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has not grown into the lining of the abdomen, called the peritoneal lining, or into the serosa, which is the outer layer of the stomach.
T4: The tumour has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has also grown into the peritoneal lining or serosa or the organs surrounding the stomach.
T4a: The tumour has grown into the serosa.
T4b: The tumour has grown into organs surrounding the stomach.

Node (N)

The “N” in the TNM staging system refers to the number of regional lymph nodes involved by the stomach cancer.

NX: Regional lymph nodes cannot be evaluated.
N0: The cancer has not spread to the regional lymph nodes.
N1: The cancer has spread to 1 to 2 regional lymph nodes.
N2: The cancer has spread to 3 to 6 regional lymph nodes.
N3: The cancer has spread to 7 or more regional lymph nodes.
N3a: The cancer has spread to 7 to 15 regional lymph nodes.
N3b: The cancer has spread to 16 or more regional lymph nodes.

Metastasis (M)

The “M” in the TNM system describes whether the stomach cancer has spread to other parts of the body, called distant metastases.

MX: Distant metastasis cannot be evaluated.
M0: The cancer has not spread to other parts of the body.
M1: The cancer has spread to another part or parts of the body.