Stomach cancer: Symptoms, Causes, Risk factors, Staging, Diagnosis, Treatment, Prevention and Long term outlook


Stomach cancer, also known as gastric cancer begins in the mucus producing cells that line the stomach. This type of cancer is called adenocarcinoma.

August 9, 2018

Stomach cancer, also known as gastric cancer begins in the mucus producing cells that line the stomach. This type of cancer is called adenocarcinoma.
As most people typically don't show symptoms in the earlier stages, this type of cancer is difficult to diagnose. For this reason, the majority of people diagnosed with stomach cancer either already have metastasis or eventually develop it. Metastasis occurs when the cancer spreads from the area in which it first developed.

Symptoms of Stomach cancer:

As the symptoms also exist in many other less serious conditions, gastric cancer may be difficult to recognize at the initial stage. For this reason many people with stomach cancer are not diagnosed until the disease is already advanced.
Early symptoms of stomach cancer may include:

  • a sensation of being very full during meals
  • swallowing difficulties, known as dysphagia
  • feeling bloated after meals
  • frequent burping
  • heartburn
  • indigestion that does not go away
  • stomachache, or pain in the breastbone
  • trapped wind
  • vomiting, which may contain blood

The following signs and symptoms should be seen as urgent in people at increased risk of developing stomach cancer:

  • dysphagia
  • indigestion, combined with unexpected weight loss, vomiting, or anemia, as well as fatigue and breathlessness
  • It is advisable to see a doctor for people aged over 55 years who develop persistent indigestion.

Individuals who develop indigestion and have at least one of the following in their medical history should also see a doctor:

  • a close relative who has/had stomach cancer
  • dysplasia, or an abnormal collection of typically precancerous cells
  • gastritis, or inflammation of the lining of the stomach
  • pernicious anemia, where the stomach does not absorb vitamin B12 properly from food
  • Barret's esophagus
  • a history of stomach ulcers

The following signs and symptoms typically become more apparent when the stomach cancer becomes more advanced:

  • a buildup of fluid in the stomach, which may cause the stomach to feel lumpy
  • anemia
  • black stools that contain blood
  • fatigue
  • loss of appetite
  • weight loss

Causes of Stomach cancer:

When the structure of DNA changes, it can disrupt the instructions that control cell growth. Cells that should die may not do so, and cells that should be newly created may be produced too rapidly or in an uncontrollable way causing cancer. The accumulating cancerous cells form a tumor that can invade nearby structures and cancer cells can break off from the tumor to spread throughout the body.
Gastroesophageal junction cancer is associated with gastrointestinal reflux disease (GERD). GERD is a condition caused by frequent back flow of stomach acid into the esophagus. There is a strong correlation between a diet high in smoked and salted foods and stomach cancer located in the main part of the stomach.   

Risk factors of Stomach cancer:

The main risk factors for gastroesophageal junction cancer are a history of GERD and obesity. Factors that increase your risk of stomach cancer located in the stomach body include:

  • Certain medical conditions: These include esophagitis, gastroesophageal reflux disease (GERD), peptic stomach ulcers, Barrett's esophagus, chronic gastritis, and stomach polyps.
  • Smoking: Regular, long-term smokers have twice the risk of developing stomach cancer compared to non-smokers.
  • Helicobacter pylori infection: This bacterium is harmless for most people. However, it can cause infection and stomach ulcers in some individuals. Chronic ulcers can have some risk in the development of gastric cancer.
  • Family history: Having a close relative who has or has had stomach cancer can increase the risk.
  • Age: The risk of developing stomach cancer increases significantly after the age of 55 years.
  • Gender: Men have twice the risk of developing stomach cancer compared with women.
  • Diet: People who regularly eat salted fish, salty foods, smoked meats, and pickled vegetables have a higher risk of developing gastric cancer.
  • Consuming foods which contain aflatoxin fungus: These may be present in crude vegetable oils, cocoa beans, tree nuts, groundnuts, figs and other dried foods and spices.
  • Previous or existing cancers: People who have or have had cancer of the esophagus or non-Hodgkin's lymphoma are more likely to develop stomach cancer. Men with previous or current prostate, bladder, or testicular cancer are at higher risk. Females with a history of cervical, ovarian, or breast cancer also are at higher risk .
  • Some surgical procedures: Surgery to the stomach or a part of the body that affects the stomach, like the vagus nerve, can increase the risk of stomach cancer.

Staging of Stomach cancer:

There are several stages of stomach cancer. The higher the stage, the more advanced the cancer is, and the lower the chances of cure.
These include:

  • Stage 0: Highly abnormal precancerous cells are present in the mucosa but have not spread to other layers of the stomach or nearby lymph nodes.
  • Stage IA: The cancer has moved into one of the next layers of the stomach, such as the submucosa, but not nearby lymph nodes.
  • Stage IB: The cancer has moved into one of the next layers of the stomach and into one or two nearby lymph nodes.
  • Stage IIA: The cancer has developed into an even deeper layer, and may have spread to one or two lymph nodes. The tumor is considered in stage IIA cancer if it has grown deep enough, even if it has not spread.
  • Stage IIB: Even if the tumor has not spread as deep as a stage IIA stomach cancer, it is considered to be in this stage if it has spread to a greater number of lymph nodes, sometimes up to 15.
  • Stage IIIA: This stage sees the cancer spread to a deeper layer and up to 15 lymph nodes or start to grow through the stomach wall and spread to fewer lymph nodes. It has also started to reach nearby organs and structures.
  • Stage IIIB: The cancer has not grown as deep as a stage IIIA stomach cancer but has spread to over 16 lymph nodes. It has started to reach nearby organs and structures.
  • Stage IIIC: The cancer has either grown through most layers of the stomach and spread to over 16 lymph nodes or spread to nearby organs and structures and up to 15 lymph nodes.
  • Stage IV: The cancer has spread to distant sites. However, it may or may not have spread to nearby lymph nodes.

Diagnosis of Stomach cancer:

Initially diagnosis will be made by a general physician who will ask the patient about their symptoms, family history, and medical history, as well as lifestyle choices, such as eating habits or smoking. They will also carry out a physical examination to check for stomach tenderness or lumpiness.
They may also order a blood test, including a test for the presence of H. pylori bacteria. If the doctor suspects possible stomach cancer, the patient will be referred to a specialist for tests. Diagnostic measures may include the following.

Gastroscopic examination or Upper endoscopy:

A thin tube containing a tiny camera is passed down your throat and into your stomach where your doctor can look for signs of cancer. If any suspicious areas are found, a piece of tissue can be collected for analysis known as biopsy.

Ultrasound scan:

The specialist may carry out this type of scan if cancer is suspected in the top part of the stomach.

Barium meal X-ray:

The patient swallows a liquid which contains barium during a barium swallow study. This helps identify the stomach during an X-ray.

Laparoscopy:

Using a procedure called a laparoscopy, the specialist can look inside the abdomen in more detail to determine how much the cancer has spread. In this procedure, , the patient is placed under a general anesthetic, and a thin tube with a camera at the end is inserted through a small incision in the lower part of the stomach.

Imaging tests:

Imaging tests such as CT scan or PET scan take a series of radiographic pictures of the inside of the body. The images help the specialist determine how advanced the cancer is, and where it has spread to in the body. These types of scans also help the doctor decide on the most appropriate treatment.

Treatment of Stomach cancer:

Your exact treatment plan for gastroesophageal junction cancer or stomach cancer depend on the stage of your cancer, your overall health and your preferences.
Aside from treating cancer cells in the stomach, the goal of treatment is to prevent the cells from spreading. Left untreated, stomach cancer may spread to the lungs, lymph nodes, bones and liver.

Surgery:

Surgery can be done to remove the part of the esophagus or stomach where the tumor is located if gastroesophageal junction cancer has not spread. The goal of surgery is to remove all of the cancer and a margin of healthy tissue, when possible. This is necessary to make sure no cancerous cells are left behind. Nearby lymph nodes are typically removed as well.
Options include:

  • Removing early stage tumors from the stomach lining. A procedure called endoscopic mucosal resection is done using endoscopy to remove very small cancers limited to the inside lining of the stomach. The endoscope is a lighted tube with a camera that is passed down your throat into your stomach. The doctor uses special tools to remove the cancer and a margin of healthy tissue from the stomach lining.
  • Removing a portion of the stomach in a procedure called subtotal gastrectomy. The surgeon removes only the portion of the stomach affected by cancer during this procedure.
  • Removing the entire stomach in a procedure called total gastrectomy. Total gastrectomy involves removing the entire stomach and some surrounding tissue. The esophagus is then connected directly to the small intestine to allow food to move through your digestive system.
  • Removing lymph nodes to look for cancer. In this process, the surgeon examines and removes lymph nodes in your abdomen to look for cancer cells.
  • Removing part of the stomach by surgery may relieve signs and symptoms of a growing tumor in people with advanced stomach cancer. Although surgery can't cure advanced stomach cancer, but it can make you more comfortable.
  • Surgery carries a risk of bleeding and infection. You may experience digestive problems if all or part of your stomach is removed.

Abdominal surgeries are significant procedures and may require prolonged recovery time. People may have to stay in hospital for two weeks or more after the procedure. This will be followed by several weeks of recovery at home.

Radiation therapy:

Energy rays are used to target and kill cancerous cells in radiation therapy. However, because of the risk of harming other nearby organs, this type of therapy is not commonly used to treat stomach cancer. But this is an option if the cancer is advanced or causing serious symptoms, such as bleeding or severe pain.

Neoadjuvant radiation:

Neoadjuvant radiation refers to the use of radiation therapy before surgery to shrink the tumors, so that they can be removed more easily.

Adjuvant radiation:

Adjuvant radiation is radiation therapy used after surgery. The aim is to kill off any remaining cancer cells around the stomach. People may experience indigestion, nausea, vomiting, and diarrhea as a result of undergoing radiation therapy. Radiation therapy to your esophagus can cause pain on swallowing and difficulty swallowing. You may be advised to have a feeding tube placed in your stomach through a small incision in your abdomen until your esophagus heals to avoid this side effect.
In cases of advanced cancer, radiation therapy may be used to relieve side effects caused by a large tumor. Radiation and chemotherapy are typically administered at the same time which is known as chemoradiotherapy, most often before surgery in gastroesophageal junction cancer.   

Chemotherapy:

Chemotherapy is a drug treatment that uses chemicals to kill cancer cells by to stoping rapidly growing cancer cells from dividing and multiplying. These drugs are known as cytotoxic medicines. Chemotherapy drugs travel throughout your body, killing cancer cells at the primary site of the cancer and also that may have spread beyond the stomach.

Neoadjuvant chemotherapy:

Neoadjuvant chemotherapy is administered before surgery to shrink the tumor so that it can be removed more easily.

Adjuvant chemotherapy

Adjuvant chemotherapy is administered after surgery to destroy any cancerous cells that may be left behind. Chemotherapy may be the preferred treatment option for certain types of gastric cancer, including gastrointestinal stromal tumors and gastric lymphoma.
Chemotherapy is often combined with radiation therapy. It may be used alone in people with advanced stomach cancer to help relieve signs and symptoms. Side effects of chemotherapy depend on which drugs are used.

Targeted drugs:

Targeted drugs are used to attack specific abnormalities within cancer cells. It direct your immune system to kill cancer cells, also known as immunotherapy. Targeted drugs used to treat stomach cancer include:

  • Trastuzumab for stomach cancer cells that produce too much HER2
  • Ramucirumab for advanced stomach cancer that hasn't responded to other treatments
  • Imatinib for a rare form of stomach cancer called gastrointestinal stromal tumor
  • Sunitinib for gastrointestinal stromal tumors
  • Regorafenib for gastrointestinal stromal tumors

Targeted drugs are often used in combination with standard chemotherapy drugs. Your doctor can decide the best treatment option for you looking at your diagnostic tests.

Palliative care:

Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care. Palliative care can be used along with aggressive treatments, such as surgery, chemotherapy and radiation therapy. People with cancer may feel better and live longer when palliative care is used along with other appropriate treatments . This can be used soon after diagnosing the disease.

Preventing stomach cancer:

The exact cause of stomach cancer is unknown, and there are no vaccines against it. Therefore, there is no way to prevent it.  However, you can lower your risk of developing stomach cancer along with other cancer by:

  • maintaining a healthy weight
  • eating a balanced, low-fat diet
  • quitting smoking
  • exercising regularly

People who have other diseases that may contribute to the cancer may have prescribe medications that can help lower the risk of stomach cancer.  Early and periodic screening test can be helpful in detecting stomach cancer. Your doctor may use one of the following screening tests to check for signs of stomach cancer:

  • physical exam
  • lab tests, such as blood and urine tests
  • imaging procedures, such as X-rays and CT scans
  • genetic tests

Long-term outlook:

The chances of recovery are better if the diagnosis is made in the early stages. The 5 year survival rate for people with stomach cancer is 30 percent years after being diagnosed. This is the case if the stomach was the original source of the cancer. It can be difficult to diagnose and stage the cancer when the origin is unknown. This makes the cancer harder to treat.
It is also more difficult to treat stomach cancer once it reaches the last stage. If your cancer is more advanced, you should consider participating in a clinical trial.
Clinical trials help determine whether a new medical procedure, device, or other treatment is effective for treating certain diseases and conditions. However, clinical trials are experimental and in no way guarantee a cure for stomach cancer.
Patients should discuss this option carefully with their doctors and family as the side effects the participants might experience are unknown.