Text F. Newer Approaches and Investigations Treatments.

 

One new approach to treating cancer is called (dose-intensity chemotherapy, which uses especially high doses of drugs. This therapy is used for tumors that have recurred even though they had a good response when first treated with drugs. Such tumors have already demonstrated sensitivity to the drug; the strategy is to markedly increase the drug dose to kill more cancer cells and thus prolong survival.

However, dose-intensity chemotherapy can cause life-threatening injury to the bone marrow. Therefore, dose-intensity chemotherapy is com­monly combined with rescue therapy, in which bone marrow is harvested before the chemother­apy is administered. After the treatment, the mar­row is returned to the patient. Blood stem cells can be isolated from a blood sample and used instead of bone marrow in some cases. Although still investigational, these treatments have been tried for breast cancer, lymphoma, Hodgkin's dis­ease, and myeloma.

A true bone marrow transplant from a tissue-matched donor (usually a sibling) can be per­formed after dose-intensity chemotherapy in people with acute leukemia. Complications in­clude graft-versus-host disease, in which the transplanted tissue destroys the host's tissue.

New techniques of radiation therapy, such as proton or neutron beam radiation, can effectively treat certain tumors. Radiation-activated dyes and photodynamic therapy show great promise.

Immunotherapy uses techniques such as bio­logic response modifiers, killer cell therapy, and humoral (antibody) therapy to stimulate the body's immune system against cancer. These techniques have been used to treat a number of different cancers such as melanoma, kidney can­cer, Kaposi's sarcoma, and leukemia.

Finally, one of the most important potential therapeutic approaches is to find drugs that help prevent cancer. Retinoids (vitamin A derivatives) have been effective in reducing the recurrence rate of some cancers, especially those of the mouth, larynx, and lungs. Unfortunately, other agents, such as beta-carotene and related anti-oxidants, have not been shown to prevent cancer.

Notes:

newer approaches новые подходы

life-threatening injury угрожающая жизни травма

 

EXERCISES

Exercise 1. Make up sentences of your own using the following words and phrases from the texts to the chapter “Causes and Risks of Cancer”.

 

an unregulated growth, to develop from, to become cancerous, to be susceptible to carcinogens, noninitiated cells, to be needed to cause cancer, to be hard to detect, a certain type of cancer, to destroy, to be more likely, genetic and environmental factors, chromosomal abnormalities, to increase the risk of cancer, to be at much higher risk of, according to, lead to.

 

Exercise 2. Study the text “Cancer and the Immune System” and say whether these statements are right or wrong. Correct them if they are wrong.

1. The body’s immune system attacks and eliminates only bacteria and other foreign substances.

2. The abnormal cells can continue to grow, resulting in cancer.

3. The presence of tumor antigens on cancer cells can activate certain red blood cells.

4. The cancer may have been growing slowly or not at all in the organ donor.

5. To improve the immune system’s ability to find and destroy cancer, researchers have developed chemical response modifiers.

6. Interferon is the best-known and most widely used biologic response modifier.

7. Almost all human cells produce interferon artificially.

8. Humoral therapy boosts the body’s production of antibodies.

9. Doctors has successfully used tuberculosis bacteria to control bladder cancer that has invaded the bladder wall.

10. The antibodies, which are synthesized in the laboratory and injected into a person, guide the drugs to cancer cells.

 

Exercise 3. Summarize the texts to the chapter “Diagnosis of Cancer” using the following introductory expressions.

 

The text covers major problems of…

The data give a new insight into the problem of…

The problem under study is rather complicated.

As far as I know…

Without going into detail I should say that…

I’d like to add that…

I’d like to stress the importance of…

In conclusion it is necessary to say…

 

Exercise 4. Discuss the meanings of the following special terms.

 

transformation, carcinogen, to cure, benign tumor, malignant tumor, leukemia, lymphoma, melanoma, biopsy, mediastinoscopy, metastases, chemotherapy.

 

Exercise 5. Learn the definition of the following special terms.

 

symptom – an anusual or abnormal bodily condition such as a rash, cough, fever, or pain. Often a distinction is made between subjective symptoms described by the patient and objective signs found by medical personnel and/or tests.

 

syndrome – a combination of symptoms usually found in a particular disease. Syndromes aid physicians in making diagnoses.

 

benign – not tending to become progressively worse or to recur; used to describe the growth of noncancerous tumors.

 

carcinoma – cancerous tumor derived from epithelia tissues in the body (glandular, skin, linings of internal organs).

 

hyperplasia – increase in mass of a tissue or organ caused by new growth of cells.

 

tumor – an enlargement or swelling due to a pathological overgrowth of tissue; tumors may be benign or malignant.

 

biopsy – removal of a segment of living tissue for pathological examination.

 

needle biopsy – insertion of a needle into a tumor or organ to remove a core of tissue or fluid for diagnosis.

 

responsive tumor – a tumor which will be killed by drug therapy. These tumors often have a high growth rate.

 

Exercise 6. Answer the following questions to the texts from the chapter “Cancer Treatment”.

 

1. What is cancer? What are the main characteristics of cancer?

2. What is used as standard cancer treatments?

3. Is cancer a curable disease?

4. What types of cancer can respond well (poorly) to chemotherapy?

5. What types of cancer are potentially curable?

6. What is known about radiation therapy (chemotherapy, combination therapy)?

7. What are the side effects of cancer treatment?

8. What types of cancer can be predicted through a genetic test?

9. What are the new approaches and investigations in treating cancer?

 

Exercise 7. Match the opposites by writing the numbers on the lines.

 

1. susceptiblechronic

2. significantdecrease

3. benigngenerally

4. acuteresistant

5. prevalentunimportant

6. particularlyrare

7. increasemalignant

Exercise 8. After each type of therapy listed below, write a disease or condition that it is used to treat.

1. immunosuppressive drugs

2. chemotherapy

3. humoral (antibody) therapy

4. radiation therapy

5. surgery

6. combination therapy

7. dose-intensity therapy

Exercise 9. Underline the correct word or phrase to complete each sentence.

 

1. Cancer can develop a) from any tissue within any organ; b) only in connective tissue cells.

2. Changes in a cell’s genetic material are a) often hard to detect; b) detected by clinical blood test.

3. People with chromosomal abnormalities have a) an increased risk of cancer; b) a decreased risk of cancer.

4. Extended exposure to ultraviolet radiation, primarily from sunlight, causes a) hypopigmentation; b) skin cancer.

5. Much of the body’s protection against cancer is carried out a) by cells of the digestive system; b) by cells of the immune system and by antibodies circulating in the bloodstream.

6. The best-known and most widely used biologic response modifier is a) cholesterol; b) interferon.

 

Exercise 10. Speak on the following.

 

1. Causes and Risks of Cancer.

2. Immunotherapy.

3. Chemotherapy.

4. Side Effects of Cancer Treatment.

SECTION 6

IMMUNE DISORDERS

Immunodeficiency Disorders

 

Immunodeficiency disorders are a group of diverse conditions in which the immune system doesn’t function adequately, so infections are more common, recur more frequently, are unusually severe, and last longer than usual.

Frequent and severe infections – whether in a newborn, a child, or an adult – that don’t respond readily to antibiotics suggest a problem with the immune system. Some problems with the immune system also lead to rare cancers or unusual infections with viruses, fungi, and bacteria.

Causes

Immunodeficiency may be present from birth (congenital immunodeficiency) or may develop later in life. Immunodeficiency disorders that are present from birth are usually hereditary. Although rare, more than 70 different hereditary immunodeficiency disorders are known. In some disorders, the number of white blood cells decreases; in others, the number of cells is normal but they malfunction. In still others, the white blood cells aren’t affected, but other components of the immune system are abnormal or missing.

Immunodeficiency that occurs later in life (acquired immunodeficiency) is usually caused by disease. Acquired immunodeficiency is much more common than congenital immunodeficiency. Some diseases cause only a minor impairment of the immune system, while others may destroy the body’s ability to fight infection. Human immunodeficiency virus (HIV) infection, which results in acquired immunodeficiency syndrome (AIDS), is well known. The virus attacks and destroys the white blood cells that normally fight viral and fungal infections. However, many different conditions can impair the immune system. In fact, nearly every prolonged serious illness affects the immune system to some degree.

People who have spleen problems often have some degree of immunodeficiency. Not only does the spleen help trap and destroy bacteria and other infective organisms that enter the bloodstream, but also it is one of the places in the body where antibodies are produced. The immune system is affected if the spleen is surgically removed or destroyed by a disease, such as sickle cell disease. People without a spleen, especially infants, are particularly susceptible to certain bacterial infections, such as those caused by Hemophilus ifluenzae, Escherichia coli, Streptococcus. Children without a spleen should be given pneumococcal and meningococcal vaccines in addition to the usual childhood vaccines. Young children without a spleen take antibiotics continuously for at least the first 5 years of life. All people with a spleen deficiency should take antibiotics at the first sign of an infection with fever.

Malnutrition can also seriously impair the immune system. The malnutrition may involve a deficiency of all nutrients, or it may involve primarily proteins and certain vitamins and minerals (especially vitamin A, iron, and zinc). When malnutrition results in a weight that is less than 80 % of the ideal weight, the immune system is usually somewhat impaired. When the weight is reduced to less than 70 % of ideal weight, the immune system is usually severely impaired. Infections, which are common in people with impaired immune system, both depress the appetite and increase the body’s metabolic demands, resulting in a vicious circle of worsening malnutrition.

How severely the immune system is impaired depends on the degree and duration of the malnutrition and on the presence or absence of an underlying disease, such as cancer. When good nutrition is restored, the immune system quickly returns to normal.