indiacancer.org - Gastric Cancer (Stomach Cancer)

Gastric Cancer

		What is the stomach?
		What is cancer of the stomach?
		What are the causes of cancer of the stomach? Can they be prevented?
		How does cancer of the stomach present?
		How is cancer of the stomach detected?
		What are staging and grading?
		How is cancer of the stomach treated?
		What are the side effects of treatment for gastric cancer?
		What is the importance of follow up?

What is the stomach?

The stomach is a food reservoir, which also helps in digestion, and is located in the upper abdomen. The stomach is J-shaped and lies slightly sideways from left to right in the left side of the abdomen, extending onto the center of the abdomen.

Food reaches the stomach through a conduit called the esophagus or the food pipe and passes from the stomach in a partially digested manner into the small intestine, the first part of which is called the duodenum, and then finally into the large bowel, which is called the colon.

The stomach is an extremely vascular organ with large number of blood vessels supplying it. It also is an extremely, well-drained lymphatic organ with multiple lymph node stations. (Lymph nodes are small bean-shaped structures, which act as stations for drainage of lymph, a clear watery fluid, which courses through out the body in transparent, thin tubes called lymph channels or lymphatics,from various organs). Thus cancer of the stomach usually has a tendency to spread very early.

The Stomach (cut open) seen from the front

What is cancer of the stomach?

The Stomach and the Liver with related tissues

Cancer of the stomach or gastric cancer is a cancer which arises from the tissues of the stomach. Most cancers of the stomach are adenocarcinomas, that is, carcinomas with a glandular content but they also may be lymphomas of the non-Hodgkin's lymphoma variety.

Because the stomach is such a capacious organ, the symptoms usually take a very long time to appear and by the time it is detected, it is usually too late.
However, some patients may be relatively lucky and that the lesion appears in the narrowed parts of the stomach and causes early obstruction or it erodes through a blood vessel very early and causes a bleed which is noticed. Those patients are also lucky in whom a peptic ulcer disease is being treated and a cancer is picked up very early incidentally.

What are the causes of cancer of the stomach? Can they be prevented?

Cancer of the stomach has strong links with the following factors:

The Stomach bed (Tissues behind the Stomach)

Generally, a man who smokes cigarettes is a candidate for cancer of the stomach as well, besides other types of cancers.

That person who indulges in a diet full of dry salted foods is also a candidate for cancer of the stomach.

The risk is also increased in those people who are unpolished rice-eaters.

The chances are always higher if there is an infection in the stomach by an organism called Helicobacter pylori.

Those patients who have a disorder of the blood called pernicious anemia.

The chances are also higher if there is a stomach disorder called atrophic gastritis or Menetrier's disease.

If the person is a patient of hereditary polyposis or familial adenomatous polyposis, which is an inherited condition mainly involving the large intestine. (But if these polyps are also present in the stomach, then they can turn cancerous.)

Usually older men are the candidates for stomach cancer.

How does cancer of the stomach present?

Gastric Cancer (The inset shows the barium meal picture)

In the more advanced stages of cancer of the stomach, there may be a blood vomiting or hematemesis.

The person may have obstructive symptoms in which he is not able to keep down his food and it comes out in a partially digested or undigested manner.
He gets early satiety, because the stomach size has become smaller, as the lumen of the stomach is occupied by the tumor. He feels that his stomach is full and his hunger is satisfied.

He also may have pain in the upper abdomen and a bloated feeling after eating any food.

There may also be evidence of nausea, which is usually mild, a loss of appetite and evidence of regurgitation of acidic food into the food pipe, which presents in the form of heartburn.

These patients also have significant weight loss and the term cancer cachexia is classic for patients with cancer of the stomach, where the size of the disease is disproportionate to the amount of weight loss the person has.

How is cancer of the stomach detected?

The doctor, besides routine examination including internal examination, that is either rectal or vaginal examination for deposits in the pelvis or above the rectum, may also look for lymph nodes in the neck especially the left side of the neck (Lymph nodes are small bean-shaped structures, which act as stations for drainage of lymph, a clear watery fluid, which courses through out the body in transparent, thin tubes called lymph channels or lymphatics,from various organs).

If these symptoms are present, the doctor may order an upper GI x-ray series or a barium series. In this, the patient is given a liquid to drink called barium sulfate and it passes down through the gastrointestinal tract, which makes it easier to visualise under x-ray. When the dye is passing through the esophagus, the investigation is known as a barium swallow. When it passes through the stomach into the first part of the duodenum, this part of the investigation is known as a barium meal and subsequent to this, the passage of the dye in an antegrade manner up to the small bowel end is called the barium meal follow-through.

The barium investigations help in delineating the lining of the upper gastrointestinal tract and any mucosal lesions can be picked up. The investigation can be further enhanced by using double contrast, in which along with barium, a little air is pushed in, to give a contrast for the mucosal or the stomach lining pattern to stand out. This makes the investigation more sensitive.

The other significant investigation, which may be done is gastroscopy, in which the doctor has to directly visualise the condition of the inner layer of the stomach or the mucosa using a thin fibreoptic, self-illuminated tube called the gastroscope. This is passed down the oral cavity with the patient being conscious and cooperating with the doctor and is able to find almost all cancers of the stomach.

To make the investigation easier, the doctor usually sprays a local anesthetic onto the back of the wall of the oral cavity. If the doctor sees any lesion, which is abnormal, then he may take a small biopsy out of it. A biopsy is a small piece of representative tissue, which is then sent to the pathologist for examination under the microscope to rule out the presence or absence of a cancer.

Gastric Cancer

What are staging and grading?

	These are terms with which you must become familiar, if you are dealing with any form of cancer. When we stage a cancer, we try to establish carefully degree of spread of the cancer and if indeed there is spread, to what extent and involving which organs. The grading of a cancer is a microscopic issue, in which the pathologist lets you know how aggressive this particular type of cancer is; well differentiated means less aggressive, moderately differentiated intermediately aggressive and poorly differentiated more aggressive. Both grading and staging help your clinician to establish the prognosis or how serious your disease is and what is going to be the likely outcome. Staging may require additional imaging tests such as CT Scan, MRI, Sonography of the abdomen, Bone scan or chest X-ray. Following are the stages of cancer of the stomach: Stage 0 is very early cancer and is found only in the innermost lining of the mucosa of the stomach wall. Stage 1: It is found in the second and/or third layers of the stomach wall and has not spread to the adjacent lymph nodes near the cancer or is in the second layer of the stomach and has spread to lymph nodes very close to the tumor (perigastric lymph nodes).
	Stage 2: One of the following criteria apply:
		It is only in the muscle layer or the third layer of the stomach and has spread to perigastric lymph nodes.
		It is in the second layer of the stomach wall and has spread to nodes further away from the tumor.
		Cancer is in all four layers of the stomach wall but has not spread to any lymph nodes or adjacent organs.
	Stage 3: One of the following criteria may apply:
		Cancer is in all four layers of the stomach and has spread to lymph nodes either very close to the tumor or further away from the tumor.
		Cancer is in the third layer of the stomach wall and has spread to lymph nodes, which are further away from the tumor.
		Cancer is in all four layers of the stomach wall and has spread to nearby tissues. It may or may not have spread to adjacent lymph nodes.
	Stage 4: It has spread to nearby tissues and lymph nodes, which are located further away from the tumor or there is evidence of the cancer having spread to other parts of the body. Recurrent gastric cancer. This is a disease which has come back after the primary therapy for the gastric cancer is over. It may recur in the stomach itself or in other parts of the body.

How is cancer of the stomach treated?

	A lot depends on the patient's constitution, the grade of his disease and its staging. Patients are usually treated by a team of specialists which utilizes a multipronged approach. This includes an an oncosurgeon and a radiotherapist. The plan of treatment is tailored to fit a patient's requirements. If necessary, chemotherapy may become an add on. Treatment strategies. The bastions for treatment for cancer of the stomach are basically surgery and chemotherapy. Radiation and biological therapy may become add-ons. Surgery is the commonest treatment for all stages of cancer of the stomach right from the beginning of modern surgery. One of the following operations may be performed by the doctor. Subtotal gastrectomy, which removes a portion of the stomach that contains cancer and parts of other tissues and lymph nodes surrounding the stomach. Usually no organs are removed except for the spleen, which is an organ in the left upper abdomen for filtering the blood and removing old blood cells. A total gastrectomy or radical gastrectomy removes the entire stomach and a small part of the esophagus, and a small part of the small intestine and other fibrofatty and lymphatic tissues near the stomach. In some cases, the spleen is also removed. Lymph nodes are carefully dissected out from around the stomach region and the esophagus is then reconnected to the small intestine so that the continuity of the gut is maintained and the patient can eat and swallow. If only a portion of the stomach is removed, a patient is usually able to eat fairly normally. Frequent small meals may be needed as well as foods which are low in sugar and high in fat and protein, especially so if the entire stomach is removed. Over a period of time, patients adjust to this new method of eating. The alternative local therapy to surgery is radiation therapy. This involves the use of high energy, penetrative rays to destroy cancer cells. It affects cancer cells only in the zone treated. Radiation therapy is also employed for palliation i.e. control of symptoms alone in an advanced cancer. Radiation therapy can also be used in adjunct to surgery or chemotherapy, either before or after. Teletherapy or external radiation is given via a machine remote from the body while brachytherapy or internal radiation is given by implanting a radioactive source within the involved tissues. Patients may or may not require both modalities of radiation. Radiotherapy, after initial planning, usually takes just 5 to 10 minutes per day, 5 days a week for about 6 weeks. This time period is flexible depending upon the modality of radiation used. Besides local therapy, the best attempt to control cancer cells circulating in the body and lodged at places other than the stomach is by using systemic therapy (therapy which affects the entire systems of the body) which is in the form of injections or oral drugs. This form of treatment is called chemotherapy. This form of treatment is given in a cyclical manner (each set of drugs is repeated usually after every 3-4 weeks). Chemotherapy can also be used in combination with surgery, radiotherapy or both, either before or after. Biological therapy employs Biological Response Modifiers (BRM's), which are substances that use the body's own immune system, either directly or indirectly, to fight cancer or to lessen the side effects of the anti cancer drugs. Some examples of BRM's are interferon-alfa and interleukin-2. Stage 0: One of the following treatment options may be entertained:
		Subtotal gastrectomy.
		Radical total gastrectomy with lymph node dissection.
	Stage 1: One of the following options may be entertained:
		Subtotal gastrectomy with associated lymphadenectomy, that is surgery to remove the lymph nodes.
		Total gastrectomy with lymphadenectomy, that is radical total gastrectomy.
	Stage 2: One of the following options may be entertained:
		Subtotal gastrectomy, total gastrectomy, or adjuvant radiotherapy after surgery or chemotherapy. Lymph node dissection may be additional.
	Stage 3: One of the following options may be entertained:
		Total gastrectomy with or without lymphadenectomy.
		Some form of gastrectomy followed by radiation and/or chemotherapy.
		Chemotherapy with or without radiation.
	Stage 4: One of the following options may be entertained:
		Palliative surgery to bypass the disease and to relieve the symptoms and to reduce the bleeding, or to remove a tumor that is blocking the stomach. In a bypass surgery, the tumor is not touched per se but the continuity of the intestine and the digestive system is established by going around the lesion and connecting the distal small intestine to the proximal esophagus or the proximal stomach.
		Additive chemotherapy for relief of symptoms.
	Recurrent gastric cancer. The treatment options allow only for palliation and that too for a very short period of time. Chemotherapy may be tried out or some form of biological therapy.

What are the side effects of treatment for gastric cancer?

	Surgery for gastric cancer should be undertaken only in institutes which are experienced in this kind of surgery. The surgery can be very morbid in the wrong hands and it is one of the technically more difficult surgeries to perform. Often the result of surgery may also not be favorable if done by inexperienced hands. Unfortunately treatment for cancer does cause damage to the healthy tissues. Please ask the clinician about any possible side effects before any form of treatment commences. The effects of radiation depend upon the dose of radiation, the size of the area radiated, and the number and size of each fraction. The commonest side effect is extreme fatigue. Although bed rest is good, most radiotherapists advise the patient to be as mobile as possible. Another common problem is that of radiation dermatitis in which the skin covering the radiated area becomes red, dry, itchy, and may show signs of scaling off. This will slowly settle down after radiation ceases, but there may be a permanent 'bronzing' of the skin. It is important to note here that this skin problem is associated only with teletherapy or external radiation therapy. Radiation also may cause nausea and vomiting, diarrhea, urinary discomfort. There may also be a fall in the white blood cells, which are needed by humans to fight infection. Usually the radiotherapist can suggest the drugs and diet necessary to alleviate such problems. The various drugs in chemotherapy cause a varied spectrum of side effects. The severity and variability of these symptoms are very individualistic, changing from patient to patient. Some of the common side effects are:
		Skin rashes.
		Loss of hair.
		Diarrhea.
		Vomiting.
		Tingling and numbness in the fingers and toes.
		Hearing loss.
	Most are temporary and recede after therapy is over. Hair growth gradually starts after cessation of chemotherapy.
	The medical oncologist will usually be able to reduce the severity and spectrum of these side effects.
	The psychology of the patient is very important during therapy. Better psychologically prepared the patient is, better are his chances of having decreased side effects. The patient should drink large quantities of water while the therapy is in progress, and preferably avoid uncooked or raw food. Water should be filtered or boiled. Any relative or person who has any sort of infection such as common cold should be asked to desist from coming close to the patient.
	Biological therapy The side effects commonly encountered with this therapy are as follows:
		Skin rashes.
		Loss of hair.
		Low grade fever.
		Rashes and bruises.
		Nausea and vomiting (usually mild).

What is the importance of follow up?

The importance of followup cannot be overemphasized. It is a fatal fallacy to assume on the patient's part that once the primary or the first phase of treatment is over, then he or she is cured. It must be stressed here that cancer has a notorious proclivity of coming back again and again. The only way to fight this is to pick up any problem when it is still early, so that it can be nipped in the bud. And the only way to do this is to follow up when the doctor calls you for the next visit. Each such visit will include a detailed history, a physical examination (including an internal i.e. a rectal or vaginal examination), a chest x-ray, an ultrasonography or a CT scan, and various other blood studies as indicated.