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Definition of leukemia: Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.*

Estimated new cases and deaths from leukemia in the United States in 2010:
- New Cases: 43,050
- Deaths: 28,840
See the online booklet What You Need To Know About™ Leukemia from National Cancer Institute to learn about leukemia symptoms, diagnosis, treatment, and questions to ask the doctor.
Adult acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell).
Adult acute lymphoblastic leukemia (ALL; also called acute lymphocytic leukemia) is a cancer of the blood and bone marrow. This type of cancer usually gets worse quickly if it is not treated.
Normally, the bone marrow makes blood stem cells (immature cells) that develop into mature blood cells over time. A blood stem cell may become a myeloid stem cell or a lymphoid stem cell.
The myeloid stem cell develops into one of three types of mature blood cells:
- Red blood cells that carry oxygen and other materials to all tissues of the body.
- Platelets that help prevent bleeding by causing blood clots to form.
- Granulocytes (white blood cells) that fight infection and disease.
The lymphoid stem cell develops into a lymphoblast cell and then into one of three types of lymphocytes (white blood cells):
- B lymphocytes that make antibodies to help fight infection.
- T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
- Natural killer cells that attack cancer cells and viruses.
Blood cell development. A blood stem cell goes through several steps to become a red blood cell, platelet, or white blood cell.
In ALL, too many stem cells develop into lymphoblasts or lymphocytes. These cells may also be called leukemic cells. These leukemic cells are not able to fight infection very well. Also, as the number of leukemic cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may cause infection, anemia, and easy bleeding. The cancer can also spread to the central nervous system (brain and spinal cord).
There are different types of treatment for patients with adult ALL.
Different types of treatment are available for patients with adult acute lymphoblastic leukemia (ALL). Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
The treatment of adult ALL usually has 2 phases.
The treatment of adult ALL is done in phases:
- Remission induction therapy: This is the first phase of treatment. Its purpose is to kill the leukemiacells in the blood and bone marrow. This puts the leukemia into remission.
- Post-remission therapy: This is the second phase of treatment. It begins once the leukemia is in remission. The purpose of post-remission therapy is to kill any remaining leukemia cells that may not be active but could begin to regrow and cause a relapse. This phase is also called remission continuation therapy.
Treatment called central nervous system (CNS) sanctuary therapy is usually given during each phase of therapy. Because chemotherapy that is given by mouth or injected into a vein may not reach leukemia cells in the CNS (brain and spinal cord), the cells are able to find "sanctuary" (hide) in the CNS. Intrathecal chemotherapy and radiation therapy are able to reach leukemia cells in the CNS and are given to kill the leukemia cells and prevent the cancer from recurring (coming back). CNS sanctuary therapy is also called CNS prophylaxis.
Four types of standard treatment are used:
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column (intrathecal chemotherapy), an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is treatment using more than one anticancer drug. The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Intrathecal chemotherapy may be used to treat adult ALL that has spread, or may spread, to the brain and spinal cord. When used to prevent cancer from spreading to the brain and spinal cord, it is called central nervous system (CNS) sanctuary therapy or CNS prophylaxis. Intrathecal chemotherapy is given in addition to chemotherapy by mouth or vein.

Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. External radiation therapy may be used to treat adult ALL that has spread, or may spread, to the brain and spinal cord. When used this way, it is called central nervous system (CNS) sanctuary therapy or CNS prophylaxis.
Chemotherapy with stem cell transplant
Stem cell transplant is a method of giving chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.
Targeted therapy drugs called tyrosine kinase inhibitors are used to treat some types of adult ALL. These drugs block the enzyme, tyrosine kinase, that causes stem cells to develop into more white blood cells (blasts) than the body needs. Two of the drugs used are imatinib mesylate (Gleevec) and dasatinib.
New types of treatment are being tested in clinical trials.
This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the National Cancer Institute's (NCI) Web site.
Biologic therapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
Patients may want to think about taking part in a clinical trial.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Patients can enter clinical trials before, during, or after starting their cancer treatment.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment..
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*Reference: Information from National Cancer Institute
For more about leukemia, visit their website.
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