Stomach cancer begin when cell that makeup the stomach, start to grow out of control. Stomach cancer is also called gastric cancer. Stomach tumor can either be benign or malignant. Benign tumor is enclosed and cannot spread to other parts of the body while malignant is a tumor that can spread to other parts of the body. Malignant tumor is also called cancer.
Stomach is a hollow, muscular organ in the upper left part of the abdomen, located between the end of the esophagus and the beginning of the small intestine. It is made up of four layers, mucosa, submucosa, muscularis and serosa layer.
>> Mucosa. This is the innermost layer of the stomach. It contains glands that secret fluid that start breaking food down.
>> Submucosa. This is the layer beneath mucosa. It is contains blood vessels, nerves and elastic collagen fibres that help to maintain shape of the stomach.
>> Muscularis. It is a layer that contains smooth muscles. Muscles help to push food to the small intestines in a controlled manner.
>> Serosa. It is the outermost layer of stomach. It is made up of loose connective tissues and coated in mucus that prevent damage from friction with other organs.
Stomach stores food that has been swallowed and assists with the absorption of some vitamins and minerals. The stomach also play part of digestion of some food especially protein. In addition to that, stomach also passes food and water into the rest of the digestive system, including the small and large bowel, where most of the processing of food takes place.
Risk factorsWhen it comes to cancer, anything that increases your probability of developing cancer is called a risk factor. Risk factors only influence development of cancer but it does not directly cause cancer. Sometimes people with risk factors do not develop the disease while those with no risk factors do develop the disease. Knowing risk factors will help you live your life making some better healthy choices to reduce the risk. The following factors may increase your risk of stomach cancer.
> Age.Gallbladder cancer is most common to older people. Commonly from 50 years and above..
>Gender. Gallbladder cancers are more common to women when compared to men.
>Bacteria. Bacteria known as helicobacter pylori is highly linked with stomach cancer. This bacteria causes inflammation of stomach and ulcers.
>Family history. For those in a family with the history of stomach cancer are said to be at increased risk of developing this disease. In addition to that, those in a family with the history of some genetic conditions such as familial adenomatous and lynch syndrome are at increased risk too.
>Diet. Eating smoked, salted fish and meat and pickled vegetable may increase a person`s chance of developing stomach cancer. Some compounds from such foods such as meat can be converted by Helicobacter pylori into compounds that are linked by cancer.
>Tobacco smoking. Substances from tobacco smoke are highly linked with cancer. Hence smokers are said to be at increased risk of developing stomach cancer especially upper portion of stomach near the esophagus.
>Previous stomach surgery. Someone who had surgery of stomach for other reasons such as ulcers is said to be at increased risk of developing stomach cancer.
>Chronic inflammation of stomach. If inflammation of stomach is left untreated it can result to development of stomach cancer.
Prevention of stomach cancer
To prevent a disease you first need to know what causes it. Unfortunately for stomach cancer there is no known specific cause of this cancer. So there is no sure way of preventing stomach cancer but there are some factors that can help in reducing your chance of developing this type of cancer. These factors include the following;
>Avoiding or quitting smoking. By avoiding tobacco smoking will reduce your chance of developing stomach cancer. >Avoid using smoked or salted food. This can be done by preserving food such as meat and fish by refrigeration instead of using smoke and salt. >Seeking treatment of stomach inflammation before becoming chronic.
Early detection and screening of stomach cancer
When it comes to cancer, early detection normally provide better treatment outcome. When stomach cancer is found early, chances for better treatment outcome are very high. For most cancers, early detection has been greatly contributed by the presence of screening processes.
Screening is the process of running some tests to someone with no symptoms of the disease with the intention of determining presence or absence of the disease. Although some people have a higher risk of getting stomach cancers than others, but it’s important to know that anyone can develop stomach cancer.
Since this cancer is not very common in Tanzania, there are no recommended routine screening tests. Those with an increased risk of developing stomach cancer such those with family history of the disease, are advised to seek medical advice from doctors. The screening test for these people may include Barium meal photofluorography and upper endoscopy.
Signs and symptoms of stomach cancer
People with stomach cancer may experience the following signs and symptoms. Sometimes, people with stomach cancer do not have any of these changes. Or, the cause of those symptom may be another medical condition that is not cancer, hence seeing your doctor upon experiencing any of those symptoms is advised. Those signs and symptoms include the following;
• Pain or burning sensation in the abdomen
• Loss of appetite
• Bloating of stomach after meals
• Heartburn or reflux
• A sense of fullness, even after a small meal
• Persistent nausea and/or vomiting.
• Unintentional loss of weight
• Vomit containing blood or blood in stool.
• Unexplained tiredness, which may be due to anemia.
Diagnosis of stomach cancer
Following suspicion of stomach cancer, doctors use various tests to locate the disease, learn if the disease has spread to other organs of the body and some tests will help to determine stage of the disease. When running those diagnostic tests, your doctor will consider some of the factors including;
• Results of your previous tests
• Your general health condition
• Type of cancer suspected
• Your age
The following are some of the diagnostic tests for stomach cancer although not everyone will need to go through all those tests during diagnosis.
• Endoscope. Endoscope is a test that involve inserting a thin lighted, flexible tube with a camera on the end which will then be passed into the mouth, down the throat and esophagus, and into the stomach. By using this test, doctor will be able to examine the stomach for any abnormalities. By using an endoscope the doctor may remove a small amount of tissue in a procedure known as a biopsy. The removed tissue will later be examined under a microscope by a pathologist to check for signs of disease.
• Endoscopic ultrasound. This test resemble to that of normal endoscope, but the endoscope has an addition of ultrasound probe at the end. The probe releases soundwaves, which echo when they bounce off anything solid such as an organ or tumor, hence the probe will produce detailed image of stomach wall. This test shows the layers of the stomach wall, as well as nearby lymph nodes and other parts of the body directly outside the stomach.
• CT scan. Computed tomography scan is a test that uses x-rays to produce images of several inside parts of the body at the same time. Computer will combine these images to produce three dimensional image that will reveal if there is a tumor or abnormalities in the body. Sometimes a special dye called contrast is given before the scanning process. Contrast will enable images to appear clear.
• MRI scan. Unlike CT scan, magnetic resonance imaging uses strong magnetic field and radio waves to produce images of inside parts of the body. The scanner takes several images of parts of the body. Computer combine these images to form three dimensional image of inside parts of the body. Before the scanning, you may be given a contrast medium so as to produce a clear image.
• PET scan. Positron imaging tomography is a test that uses special radioactive sugar called tracer and camera to produce picture of inside organs of the body. During the test, radioactive sugar is injected into the body where it will be absorbed by cells. Since cancer cells requires more energy than normal cells, more radioactive sugar will be absorbed by cancer cells. Special camera is used to scan the body. Pictures from the scanner will show areas of the body with more concentration of this sugar which is the indication of cancer cells.
• Biopsy. Biopsy is a test that involve taking small sample of tumor and viewing it under microscope in the laboratory. This test is done by the pathologist (a doctor specialized in evaluating and interpreting cells and tissues under microscope in the laboratory). Biopsy is used as confirmatory test in most types of cancers including stomach cancer.
Stages of stomach cancer
Staging is a standard way used by cancer care team to explain how far the cancer has grown or spread. Staging also enables the oncology team to decide on the suitable treatment option. In this process of staging doctors normally use systems in order to describe the stage of cancer. For stomach cancer, doctors prefer to use TNM staging system (tumor, node and metastasis) to describe stage of the disease.
TNM staging system
TNM system is the combination of three worlds, tumor, node and metastasis.
• Tumor. Tumor explains size (how large is the tumor?) and its location.
• Node. This explain lymph nodes involved
• Metastasis. Metastasis explains how far the cancer has spread
There are five stages of stomach cancer under this system (0–IV). More discerption on this TNM system is as follows;.
Tumor (T). TX: The primary tumor cannot be evaluated.
T0: There is no evidence of a primary tumor in the stomach.
Tis: Carcinoma in situ. The cancer is found only in cells on the surface of the inner lining Of the stomach
T1: The tumor has grown into the lamina propria (layer beneath mucosa epithelium), Muscularis mucosae, or the submucosa which are inner layers of stomach wall.
• T1a: The tumor has grown into the lamina propria or muscularis mucosae.
• T1b: The tumor has grown into the submucosa.
T2: The tumor has grown into the muscle layer of the stomach (muscularis propria).
T3: The tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach, but it has not grown into serosa.
T4: The tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach and has grown into serosa or the organs surrounding the stomach.
• T4a: The tumor has grown into the serosa.
• T4b: The tumor has grown into organs surrounding the stomach.
NX: Regional lymph nodes cannot be evaluated.
N0: There is no evidence of regional lymph node involvement.
N1: 1 to 2 regional lymph nodes are involved
N2: 3 to 6 regional lymph nodes are involved
N3: 7 or more regional lymph nodes are involved
• N3a: 7 to 15 regional lymph nodes are involved
• N3b: 16 or more regional lymph nodes are involved.
M0: There is no evidence of spread to other parts of the body (no distant metastasis).
M1: The cancer has spread to another part or parts of the body (there is metastasis).
Stage 0 (Tis, N0, M0): This is also called carcinoma in situ and there is no evidence of reginal lymph node involvement or distant metastasis.
Stage IA (T1, N0, M0): Tumor has grown into the inner layers of the stomach wall. There is no reginal lymph node involvement or distant metastasis.
Stage IB (T1, N1, M0): Tumor has grown into the inner layers of stomach wall. There is 1 to 2 reginal lymph node involvement.
(T2, N0, M0): Tumor has grown into muscular layers of stomach wall. There is no evidence of lymph node involvement or distant metastasis.
Stage IIA (T1, N2, M0): Tumor has grown into inner layers of stomach. There is 3 to 6 reginal lymph node involvement with no evidence of distant metastasis.
(T2, N1, M0): Tumor has grown into muscular layers of stomach wall. There is 1 to 2 reginal lymph node involvement with no evidence of distant metastasis.
(T3, N0, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach, but it has not grown into serosa. There is no evidence of reginal lymph node involvement or distant metastasis.
Stage IIB (T1, N3, M0): Tumor has grown into the inner layers of stomach wall. There are 7 or more lymph nodes involved with no evidence of distant metastasis.
(T2, N2, M0): Tumor has grown into muscular layers of stomach wall. There are 3 to 6 reginal lymph nodes involved with no evidence of distant metastasis.
(T3, N1, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into serosa. There is 1to 2 reginal lymph node involvement.
(T4a, N0, M0): Tumor has grown through all of the layers of the muscle into the connective tissue. It has grown into serosa. There is no evidence of reginal lymph node involvement or distant metastasis.
Stage IIIA (T2, N3, M0): Tumor has grown into muscular layers of stomach wall. There is 7 or more lymph node involvement with no evidence of distant metastasis.
(T3, N2, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into serosa. There are 3 to 6 reginal lymph node involved with no evidence of distant metastasis.
(T4a, N1, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has grown into serosa. There is 1 to 2 reginal lymph nodes involved with no evidence of distant metastasis.
Stage IIIB (T3, N3, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach but has not grown into serosa. There are 7 or more reginal lymph nodes involved with no evidence of distant metastasis.
(T4a, N2, M0): Tumor has grown through all of the layers of the muscle into the connective tissue outside the stomach. It has grown into serosa. There are 3 to 6 reginal lymph nodes involved with no evidence of distant metastasis.
(T4b, N0 or N1, M0): Tumor 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. Tumor may or may not have spread to 1 to 2 reginal lymph nodes but there is no evidence of distant metastasis.
Stage IV (Any T, any N, M1): Tumor is of any size with any extent of reginal lymph node involvement. Tumor has also spread to other organs around the stomach.
After being diagnosed with stomach cancer, your doctor will give you the news and most of times it is very difficult for people to accept the news due to the nature of disease itself. After hearing the news, many will start asking themselves different questions like,
• Am I going to die?
• How am I going to eat?
• What should I do?
• Is there any possible solution for this?
Making treatment decision
When helping you with some of your questions that you may have, one of the things that you will talk about with your doctor is availability of any possible solution for your case. So here comes the crucial part that include making treatment decision as there are many treatment options and in order to decide what is the right choice for you, you will need to be careful and get all the help you can get in making decision.
Talk with your doctor
Your doctor will discuss with you about all the treatment options available for your case. During the discussion you will talk about their goals and possible side effects. Among other things that your doctor will consider when presenting to you the options are;
• Your age
• Any other serious health conditions you have
• Type and stage your cancer
• Chances that the treatment option will cure you or help in some any way
• How do you feel about the possible side effects from treatment options?
After listening to the doctor, do not rush to make the decision but take your time to absorb the information that you have just received and ask questions if there is anything that you have not understood or not sure about. Many people prefer to have a family member or friend with them in order to take part in the discussion making, taking notes or simply listen.
Second OptionAfter hearing all the options available from your doctor, you may want to get a second opinion from another specialist to confirm or seek more clarification on your doctor’s recommendations or reassurance that you have explored all of your options. Some doctors can even send you together with your initial results to another specialist for more opinions on your case.
Take part in clinical trials
Clinical trials are new drugs or modified mode of treatment or new treatment combination for cases like yours that are to be tested if they are effective to be used as standard care treatment options or not. Your doctor or nurse will discuss with you if you want to take part in clinical trial.
Over the years, trials have improved treatments and led to better outcomes to people diagnosed with various diseases including cancer. If you have decided to take part in clinical trial, you can also withdraw at any time
Treatment of stomach cancer requires a team of doctors and other health care professionals. This team work together and it is called multidisciplinary team. Team may vary depending on the treatment option for a particular case. But generally multidisciplinary team for treatment of stomach cancer includes, surgical oncologist, gastroenterologist, medical oncologist, radiation oncologist, endoscopist, pathologist and other health care professionals like oncology nurses, physiotherapist and palliative care team. Treatment options include the following;
Surgery is the removal of the tumor and some surrounding healthy tissue during an operation. There are different types of surgery for stomach cancer that will depend on the location of the tumor and how advanced the cancer is. These type of surgery include the following;
• Subtotal or partial gastrectomy. In this type cancerous part of the stomach is removed, along with nearby fatty tissue (omentum) and lymph nodes. The upper stomach and oesophagus are usually left intact. This type of surgery is used when cancer is still only in the stomach.
• Total gastrectomy. This is used when cancer is at advanced stage. Surgeon will removal the whole stomach, along with nearby fatty tissue (omentum), lymph nodes and parts of adjacent organs, if necessary. Surgeon will reconnects the esophagus to the small bowel. The top part of this connection (which is a tube of intestine) takes over some of the function of the stomach. When this connection is healing, small feeding tube will be placed further down the small bowel and out through abdomen.
• Risk of infection.
• Excess bleeding.
• Blood clots.
• Damage to nearby organs or leaking from the connections between the oesophagus and stomach or small bowel.
Radiation therapy is a treatment of cancer by using high energy x-rays or other radiation particles to destroy cancer cells. Radiation therapy is given by a specialized doctor known as radiation oncologist. There are two main types of radiation therapy, internal radiation therapy (brachytherapy) or external beam radiation therapy. Stomach cancer patients are normally treated by using external beam radiation therapy.
Side effects of radiotherapySide effects of radiation therapy depend on the dose of radiation therapy given. These side effects normally go away soon after completion of treatment but also there are some medications that may help to relieve if they become too severe. Some of the possible side effects include the following;
• Mild skin reactions at the site of irradiation
• Loose bowel movement
• Upset stomach
• Loss of appetite.
Chemotherapy is the use of drugs to destroy cancer cells or stop its growth and division. This treatment is given by a specialized doctor known as medical oncologist. Type of chemotherapy used for treatment of stomach cancer is known as systemic chemotherapy. In systemic chemotherapy drug gets into the bloodstream to reach cancer cells throughout the body.
Generally chemotherapy is can be given through injection into vein (intravenously) by using a needle or given as a pill or capsule that is swallowed (orally). Chemotherapy can sometimes be given in combination with radiation therapy or surgery
Side effects of radiotherapy• Hair loss
• Nausea and/or vomiting
• Loss of appetite
• Feeling tired due to low red blood cells count
• Risk of infection due to decreased white blood cells
• Easily bruising and bleeding due to low blood platelets.
• Changed bowel habits such as constipation or diarrhoea.