Stomach Cancer And Gastric Malignancies Biology Essay

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Stomach cancer is the fourth most common cancer worldwide with 930,000 cases diagnosed in 2002. It is a disease with a high death rate (~800,000 per year) making it the second most common cause of cancer death worldwide after lung cancer. It is more common in men and in developing countries.

It represents roughly 2percent (25,500 cases) of all new cancer cases yearly in the United States, but it is more common in other countries. It is the leading cancer mode in Korea, with 20.8percent of malignant neoplasm.

Metastasis occurs in 80-90percent of individuals with stomach cancer, with a six-month survival rate of 65percent in those diagnosed in early stages and less than 15percent of those diagnosed in late stages.

One in a million people under the age of 55 seeking medical attention for indigestion has stomach cancer and one in 50 of all ages seeking medical attention for burping and indigestion have stomach cancer. Out of 10 million people in the Czech Republic, only three new cases of stomach cancer in people under 30 years of age in 1999 were diagnosed. Other studies show that less than 5percent of stomach cancers occur in people less than 40 years of age with 81.1percent of that 5percent in the age group of 30 to 39 and 18.9percent in the age group of 20 to 29. For Taiwan the mortality was 11.75 per 100,000 in 1996.Gastric cancer shows a male predominance in its incidence as up to three males are affected for every female. A very small percentage of diffuse-type gastric cancers are thought to be genetic. Hereditary Diffuse Gastric Cancer (HDGC) has recently been identified and research is ongoing. However, genetic testing and treatment options are already available for families at risk. In more detail, H. pylori is the main risk factor in 65-80percent of gastric cancers, but in only 2percent of such infections. Approximately ten percent of cases show a genetic component. In Japan and other countries, bracken consumption and spores are correlated with incidence of stomach cancer, though causality has yet to be established.

5. Symptoms

Stomach cancer is frequently asymptomatic or causes only nonspecific symptoms in its early stages. By the time symptoms occur, the cancer has frequently reached an advanced stage (see below), one of the main reasons for its poor prognosis.

Stomach cancer can cause the following signs and symptoms:

Stage one (Early)

Indigestion or a burning sensation (heartburn)

Loss of appetite, especially for meat

Abdominal discomfort or irritation

Stage two (Middle)

Weakness and fatigue

Bloating of the stomach, usually after meals

Stage three (Late)

Abdominal pain in the upper abdomen

Nausea and occasional vomiting

Diarrhea or constipation

Weight loss

Bleeding (vomiting blood or having blood in the stool) which will appear as black. This can lead to anemia.

Dysphagia; this feature suggests a tumor in the cardia or extension of the gastric tumor in to the esophagus.

Note that these can be symptoms of other problems like a stomach virus, gastric ulcer or tropical sprue. Diagnosis should be done through a gastroenterologist or an oncologist.

6. Causes

Infection through Helicobacter pylori is believed to be the cause of most stomach cancer while autoimmune atrophic gastritis, intestinal metaplasia and various genetic factors are associated with increased risk levels. The Merck Manual states that diet plays no role in the genesis of stomach cancer. However, the American Cancer Society lists the following dietary risks for stomach cancer,

A. smoked foods

B. salted fish and meat

C. pickled vegetables

D. Nitrates and nitrites are substances commonly found in cured meats. They can be converted through certain bacteria, like H. pylori, into compounds that have been found to cause stomach cancer in animals.

A very important but preventable cause of gastric cancer is tobacco smoking. Smoking increases, the risk of developing gastric cancer considerably, from 40percent increased risk for current smokers to 82percent increase for heavy smokers, which is nearly twice the risk for non-smoking population. Another lifestyle cause of gastric cancer besides smoking is consumption of alcohol.

6. Complications of disease

A. Fluid buildup in the belly area (ascites)

B.Gastrointestinal bleeding

C.Spread of cancer to other organs or tissues

D.Weight loss

7. Subtypes

Several unique kinds of cancer can occur in the stomach. The most common mode is called adenocarcinoma, which begins from one of the common cell kinds found in the lining of the stomach.

Gastric adenocarcinoma . Stomach cancers are overwhelmingly adenocarcinomas (90percent). Histologically, there's two major kinds of gastric adenocarcinoma

{Lauren classification}

1. Intestinal type

Intestinal mode adenocarcinoma tumour cells describe irregular tubular structures, harbouring pluristratification, multiple lumens, reduced stroma ("back to back" aspect). Often, it associates intestinal metaplasia in neighbouring mucosa.

2. Diffuse type. Diffuse mode adenocarcinoma (mucinous, colloid, linitis plastica, leather-bottle stomach). Tumour cells are discohesive and secrete mucus, which is delivered in the interstitium producing huge pools of mucus/colloid (optically "empty" spaces). It is poorly differentiated.

Around 5percent of gastric malignancies are lymphomas.

Carcinoid and stromal tumors may also occur.

Depending on glandular architecture, cellular pleomorphism and mucosecretion, adenocarcinoma may present three degrees of differentiation:

1. Well

2. Moderate

3. Poorly differentiated.


If cancer cells are found in the tissue sample, the next process is to stage, or get out the extent of the disease. Various tests decide whether the cancer has spread and, if so, what parts of the body are affected. Because stomach cancer can spread to the liver, the pancreas, as well as other organs near the stomach as well as to the lungs, the doctor may order a CT scan, a PET scan, an endoscopic ultrasound exam, or other tests to check these areas. Blood tests for tumor markers, like carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) may be ordered, as their levels correlate to extent of metastasis, especially to the liver, as well as the cure rate.

Staging may not be complete until after surgery. The surgeon removes nearby lymph nodes and possibly samples of tissue from other areas in the abdomen for examination through a pathologist.

The clinical stages of stomach cancer are:

Stage 0. Limited to the inner lining of the stomach. Treatable through endoscopic mucosal resection when found very early (in routine screenings); otherwise through gastrectomy and lymphadenectomy without need for chemotherapy or radiation.

Stage I. Penetration to the second or third layers of the stomach (Stage 1A) or to the second layer and nearby lymph nodes (Stage 1B). Stage 1A is treated through surgery, including removal of the omentum. Stage 1B may be treated with chemotherapy (5-fluorouracil) and radiation therapy.

Stage II. Penetration to the second layer and more distant lymph nodes, or the third layer and only nearby lymph nodes, or all four layers but not the lymph nodes. Treated as for Stage I, sometimes with additional neoadjuvant chemotherapy.

Stage III. Penetration to the third layer and more distant lymph nodes, or penetration to the fourth layer and either nearby tissues or nearby or more distant lymph nodes. Treated as for Stage II, a cure is still possible in some cases.

Stage IV. Cancer has spread to nearby tissues and more distant lymph nodes, or has metastatized to other organs. A cure is very rarely possible at this stage. Some other techniques to prolong life or improve symptoms are used, including laser treatment, surgery, and/or stents to keep the digestive tract open, as well as chemotherapy through drugs like 5-fluorouracil, cisplatin, epirubicin, etoposide, docetaxel, oxaliplatin, capecitabine, or irinotecan.

The TNM staging method is also used.

Primary tumor (T)

TX: Primary tumor cannot be assessed

T0: No evidence of primary tumor

Tis: Carcinoma in situ: intraepithelial tumor without invasion of the lamina propria

T1: Tumor invades lamina propria or submucosa

T2: Tumor invades the muscularis propria or the subserosa

T2a: Tumor invades muscularis propria

T2b: Tumor invades subserosa

T3: Tumor penetrates the serosa (visceral peritoneum) without invading adjacent structures

T4: Tumor invades adjacent structures

Regional lymph nodes (N)

NX: Regional lymph node(s) cannot be assessed

N0: No regional lymph node metastasis

N1: Metastasis in one to six regional lymph nodes

N2: Metastasis in seven to 15 regional lymph nodes

N3: Metastasis in more than 15 regional lymph nodes

Distant metastasis (M)

MX: Distant metastasis cannot be assessed

M0: No distant metastasis

M1: Distant metastasis


Stage Classification

0 Tis, N0, M0

IA T1, N0,M0

IB T1, T2, M0

T2a, N0, M0

T2b, N0, M0

II T1, N2, M0

T2a, N1, M0

T2b, N1, M0

T3, N0, M0

IIIA T2a, N2, M0

T2b, N2, M0

T3, N1, M0

T4, N0, M0

IIIB T3, N2, M0

IV T4, N1, M0

T4, N2, M0

T4, N3, M0

T1, N3, M0

T2, N3, M0

T3, N3, M0

Any T, N, M1

8. Treatment options/ Indications

As with cancer, treatment is adapted to fit each people individual needs and depends on the size, location, as well as extent of the tumour, the stage of the disease, as well as general health. Cancer of the stomach is difficult to cure unless it is found in an early stage (before it has begun to spread). Unfortunately, because early stomach cancer causes few symptoms, the disease is usually advanced when the diagnosis is made. Treatment for stomach cancer may include surgery, chemotherapy, and/or radiation therapy.

9. Medical Treatment

The most commonly used standard drug combinations for stomach cancer before or after surgery are ECF and ECX.

ECF contains the drugs epirubicin, cisplatin and fluorouracil. There is a page on the specific side effects of ECF in our section on cancer drugs.

You have ECF through injection and through a pump. You will need a central line. This is a tube that goes into a main blood vessel in your neck. The end of the tube comes out of your chest. This attaches to the pump. You may have four to six months of treatment depending on how your cancer responds.

ECX contains the drugs epirubicin, cisplatin and capecitabine (Xeloda). There is a page about the side effects of ECX in our section on cancer drugs. You have the epirubicin and cisplatin into a vein but the capecitabine is taken as a tablet.


After several trials, significant survival advantage deriving from the use of chemotherapy as a definitive treatment for gastric cancer has not been reported. It is important to note, however, that one study19 revealed recurrence rates of up to 80 percent in patients undergoing surgical resection alone, suggesting a must continue investigation of adjuvant chemotherapy and radiotherapy.

Chemotherapy drugs can be taken as tablets, or given into a vein (intravenously) as injections or drips (infusions).

The chemotherapy drug fluorouracil - or 5FU - may be given continuously through a central line or a PICC line attached to a small pump. The pump allows a low dose of the drug to be given day and night, while you are at home. The pump can be carried round in a small bag strapped around the waist or over the shoulder. If you are having this mode of chemotherapy, your doctors or nurses will explain how to use the pump. Chemotherapy is given in cycles of treatment. A cycle frequently takes three weeks. On the first day of each cycle, you will usually be given chemotherapy through injection or infusion. This is frequently followed through a continuous infusion of chemotherapy or chemotherapy tablets to take at home. Your doctor or nurse will tell you how lots of cycles of treatment are planned for you and explain exactly how you will be given your chemotherapy.

10. Complications of medical treatment

• Hair loss

• Nausea and Vomiting

• Low white blood count

• Anemia

• Low platelet count

• Tumor Lysis syndrome

• Kidney damage

• Lung damage

• Liver damage

• Heart damage

• Damage to the veins

11. Surgical Treatment

Surgery is the most common treatment. The surgeon removes segment or all of the stomach, as well as the surrounding lymph nodes, with the simple goal of removing all cancer and a margin of average tissue. Depending on the extent of invasion and the location of the tumour, surgery may also include removal of segment of the intestine or pancreas. Tumors in the lower segment of the stomach may call for a Billroth I or Billroth II procedure.

Endoscopic mucosal resection (EMR) is a treatment for early gastric cancer (tumour only involves the mucosa) that has been pioneered in Japan, but is also available in the United States at some centres. In this procedure, the tumour, together with the inner lining of stomach (mucosa), is removed from the wall of the stomach using an electrical wire loop through the endoscope. The advantage is that it is a much smaller operation than removing the stomach.

Endoscopic submucosal dissection (ESD) is a similar technique pioneered in Japan, used to resect a huge area of mucosa in one piece. If the pathologic examination of the resected specimen shows incomplete resection or deep invasion through tumour, the patient would need a formal stomach resection.

Surgical interventions are currently curative in less than 40percent of cases, and, in cases of metastasis, may only be palliative.

12. Complications of Surgery

Organ Injury



Blood Clots or Bleeding

13. Radiation

Radiation therapy (also called radiotherapy) is the use of high-energy rays to damage cancer cells and stop them from growing. When used, it is generally in combination with surgery and chemotherapy, or used only with chemotherapy in cases where the individual is unable to undergo surgery. Radiation therapy may be used to relieve pain or blockage through shrinking the tumour for palliation of incurable disease.


Side effects from radiation therapy to the stomach and abdomen include,

1. Queasiness

2. Nausea

3. Diarrhea.

4. Fatigue

5. Poor appetite.

6. Difficulty swallowing or sore throat

14. Multimodality therapy

While past studies of multimodality therapy (combinations of surgery, chemotherapy and radiation therapy) give mixed results.

Some facts

Protective factors

Eating fresh fruits and vegetables that contain antioxidant vitamins (such as A and C) appears to lower the risk of stomach cancer."

There is a well-known remedy that eating jalapeno peppers daily can help reduce the pain of stomach cancer. Some think this is because it reduces the gastric acid in your stomach and helps numb the stomach walls.

The following may help reduce your risk of gastric cancer:

1. Don't smoke

2. Eat a healthy, balanced diet wealthy in fruits and vegetables

3. Take a medication to treat reflux disease, if you have it

15. Exams and Tests

The following tests can help diagnose gastric cancer:

• Complete blood count (CBC) to check for anemia

• Esophagogastroduodenoscopy (EGD) with biopsy

• Stool test to check for blood in the stools

• Upper GI series

15. Case Study with photograph

Endoscopic image of linitis plastica, a mode of stomach cancer where the whole stomach is invaded, leading to a leather bottle-like appearance with blood coming out of it.

16. Latest Articles or references/ net links

1. Rustgi AK. Neoplasms of the stomach. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 202.

2. Gunderson LL, Donohue JH, Alberts SR. Cancer of the stomach. In: Abeloff MD, et al., eds. Abeloffs Clinical Oncology. Fourth ed. Philadelphia, Pa: Saunders Elsevier; 2008: chap 79.

3. National Cancer Institute. Gastric cancer treatment PDQ. Updated July 8, 2010.





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