How chemotherapy works to treat cancer? Can chemotherapy cure cancer?

Chemotherapy

Chemotherapy which simply means the use of drugs or medications to treat disease came into general use in the 1970s after clinical trials proved them to be effective in treating cancer. To many people, chemotherapy is frightening because of the fears of side effects that are sometimes caused by the use of the potent drugs needed to disrupt the cancer cells' ability to grow and multiply. The use of chemotherapy drugs has been greatly refined over the years, so that many of the earlier side effects have been modified. Chemotherapy may be given in several ways. Sometimes drugs are given in pill or capsule form and taken by mouth. Other times they may be injected into a muscle or given through a vein. How fast the cancer cells are destroyed may vary with the medication and the type of cancer. Because each drug acts on the cell in its own way, and at different times in the cell cycle, using them in combination can be more effective than using any one of them individually. Some are given on a weekly basis, others, monthly or daily, sometimes for periods of one or two years following the initial treatment. Because most anticancer drugs have the potential for dangerous side effects, they must be administered carefully by medical professionals experienced in their use. Chemotherapy has proven to be very effective in cancer treatment. It is estimated that more than 50,000 cancer patients are being cured each year with the use of anticancer drugs, either alone or combined with radiation therapy and/or surgery.

What is chemotherapy? 

Chemo means "chemical," and therapy means "treatment"; thus chemotherapy is simply the treatment of cancer using chemicals (drugs).

What does chemotherapy do? 

In simple terms, the chemicals destroy the cancer cells, either by interfering with their growth or by preventing them from reproducing. The various drugs work in different ways to interrupt the cell life cycle. Some affect the cell during one or more of its phases of growth and have no adverse effect on the cell during the other phases; others affect the cell throughout the whole cycle. The idea behind the use of chemotherapy is to slow down the multiplying of cancer cells or to destroy the cancer cells themselves.

Has chemotherapy as a treatment been used for a long time? 

Although the use of chemicals to fight disease has been known for a long time, chemotherapy has been used against cancer only in recent years. Until the 1940s, attempts to find drugs that would selectively destroy cancer cells were not successful. The observation at Yale University that the potent World War I gas nitrogen mustard produced selective damage to the lymphatic system and bone marrow led to interest in the use of chemotherapy for cancer. The first successful use of chemotherapy was at Yale in the mid 1940s. During the 1960s and 1970s the uses and successes of chemotherapy expanded rapidly.

How Chemotherapy Works

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When is chemotherapy used? 

Chemotherapy is used for many different reasons:

• It can cure some kinds of cancer.

• It can be used to achieve long term remissions in some kinds of cancer.

• It can be used to reduce a large tumor, making it small enough to remove by surgery.

• It can be used after surgery to kill the cells which may have been left or are in another part of the body.

• It can be used to shrink tumors which cannot be surgically removed.

• It can be used to make radiation treatment more effective.

• It can prevent or relieve pain or control unpleasant symptoms.

Is chemotherapy usually used alone as a treatment? 

Like other treatments for cancer, chemotherapy is sometimes used alone. Most of the time chemotherapy is used in combination with another kind of treatment radiation therapy or surgery.

What does chemotherapy do that is different from the other kinds of treatments? 

The chemotherapeutic drugs enter the bloodstream either directly by intravenous injection or indirectly by absorption through the stomach tissues. Therefore, the drugs are transported wherever tumor cells may be growing. This is different from surgery and radiotherapy, which concentrate on a specific part or region of the body for treatment. Chemotherapy is used when there is the possibility that cancer cells may be deposited in a different place from the primary tumor or may be circulating throughout the body via the bloodstream.

Can chemotherapy ever cure cancer? 

According to the National Cancer Institute, the drugs can produce cures in about 15 percent of clinical cancer. In many of the remaining cases, they often temporarily stop the growth, or relieve pain and allow the patient to live a longer, more comfortable life. In some cancers, in some patients, chemotherapy can cause the tumors to disappear. In other cases, chemotherapy makes the tumor shrink. When this doesn't happen, the drugs may at least stop the tumor from growing or make it grow more slowly. There are a few cases, however, in which chemotherapy has no effect on the growth of the tumor.

Cancer Treatment: Chemotherapy

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Isn't chemotherapy used only as a last resort for advanced cancer cases? 

During the early years, when chemotherapy was an investigative treatment, it was used primarily on patients after other treatments were no longer working. Today, many doctors are using chemotherapy to prevent the spread of cancer for persons with minimal disease. When the drug is used early, the main idea is to remove the micrometastases which are not yet seen under the microscope, but are believed to be present, especially in some stages of breast cancer.