Acute lymphoblastic leukemia (ALL) is a type of blood cancer. Also known as acute lymphocytic leukemia or acute lymphoid leukemia, it is the least common type of leukemia in adults. Here's what you need to know about symptoms, prognosis, survival rates, and treatment for ALL.
What Is Acute Lymphoblastic Leukemia?
ALL is a type of leukemia that starts from white blood cells in the bone marrow, the soft inner part of bones. It develops from cells called lymphocytes, a type of white blood cell central to the immune system, or from lymphoblasts, an immature type of lymphocyte.
Acute lymphoblastic leukemia invades the blood and can spread throughout the body to other organs, such as the liver, spleen, and lymph nodes. But it does not normally produce tumors as do many types of cancer. It is an acute type of leukemia, which means it can progress quickly. Without treatment, it can be fatal within a few months.
The outlook for acute lymphoblastic leukemia depends on factors such as:
- Your age: Younger patients tend to have a better outlook.
- Your lab test results: The prognosis is better if you have a lower white blood count when you're diagnosed.
- Your subtype of ALL (B-cell ALL or T-cell ALL)
- Whether you have a chromosome abnormality called the Philadelphia chromosome; having it suggests a poorer prognosis.
- Your response to chemotherapy: The prognosis is better if you have no evidence of leukemia four to five weeks after starting treatment.
Risk Factors for Acute Lymphoblastic Leukemia
For most people, the cause of ALL is unknown. For this reason, there is no known way to prevent it. However, there are a few known risk factors for this type of leukemia. This means these factors may increase your chances of getting acute lymphoblastic leukemia. But it is not yet known whether these risk factors are actual causes of the disease:
- Exposure to high levels of radiation to treat other types of cancer
- Exposure to certain chemicals such as benzene, a solvent used in oil refineries and other industries and present in cigarette smoke, certain cleaning products, detergents, and paint strippers
- Infection with human T-cell lymphoma/leukemia virus-1 (HTLV-1) in rarer cases outside the U.S., or Epstein-Barr virus (EBV), a related leukemia more commonly seen in Africa
- Having an inherited genetic syndrome such as Down syndrome
- Being white
- Being male
Symptoms of Acute Lymphoblastic Leukemia
ALL can cause a variety of symptoms. Some of these can be vague and not specific just to leukemia. They include:
Many symptoms of acute lymphoblastic leukemia are the result of a shortage of normal blood cells. That's because leukemia cells crowd out these normal cells in the bone marrow.
A shortage of red blood cells may cause symptoms of anemia, including:
A shortage of normal white blood cells may result in:
- Recurring infections
A shortage of blood platelets may cause symptoms such as:
- Lots of bruising for no obvious reason
- Frequent or severe nosebleeds, bleeding gums, or other unusual bleeding such as from minor cuts
Depending upon where leukemia cells are present, other symptoms may include:
- A full or swollen belly from leukemia cells in the liver or spleen
- Enlarged lymph nodes such as in the neck or groin, under arms, or above the collarbone
- Bone or joint pain
- Headache, trouble with balance, vomiting, seizures, or blurred vision if the cancer has spread to the brain
- Trouble breathing if spread has occurred in the chest area
Treatment for Acute Lymphoblastic Leukemia
ALL is really a group of related diseases, or subtypes. Therefore, your treatment options depend upon your subtype and other factors. You may have more than one type of treatment. These include:
Chemotherapy, the use of anticancer drugs in combination, generally over a couple of years. Agents used for ALL include:
- cyclophosphamide (Cytoxan)
- cytarabine (Cytosar)
- daunorubicin (Cerubidine) or doxorubicin (Adriamycin)
- etoposide (VP-16)
- L-asparaginace (Elspar) or PEG-L-asapraginase (Oncaspar)
- 6-mercaptopurine (6-MP, Purinethol)
- methotrexate (Rheumatrex, Trexall)
- methoterate oral (Xatmep)
- steroids (prednisone, dexamethasone)
- teniposide (Vumon
- vincristine (Oncovin)
- Targeted therapy, drugs that target specific parts of cancer cells and tend to have fewer or less severe side effects than chemotherapy; examples include blinatumomab (Blincyto), dasatinib (Sprycel), imatinib (Gleevec), and nilotinib (Tasigna), ponatinib (Iclusig), which attack cells with the Philadelphia chromosome.
- Radiation therapy, the use of high-energy radiation to kill cancer cells; this is not used often for ALL, but may be used to treat leukemia in the brain or bone, for example, or before a stem cell transplant.
- A bone marrow transplant, which involves use of high doses of chemotherapy and possibly radiation followed by a transplant of bone-forming stem cells. Stem cells usually come from a donor, or less likely, from your own bone marrow or peripheral blood. If you cannot tolerate high doses of chemotherapy and radiation, lower doses may be used with a "mini-transplant."
Treatment occurs in two parts -- induction therapy and post-induction therapy.
The goal of induction therapy is to achieve remission by:
- Killing as many leukemia cells as possible
- Returning blood counts to normal
- Ridding the body of signs of disease for a long time
About eight or nine out of 10 adults achieve remission after treatments, but many relapse, which lowers the overall cure rate to 30% to 40%. So even with remission, post-induction therapy is needed to prevent relapse. It involves cycles of treatment over two to three years. Usually, the drugs are different than the drugs used in induction therapy. The goal is to completely rid the body of leukemia cells that have not been found by common blood or marrow tests.
The FDA has approved a form of immune cell gene therapy called CAR T-cell therapy. It uses some of your own immune cells, called T cells, to treat your cancer. Doctors take the cells out of your blood and add new genes to them. The new T cells are better able to find and kill cancer cells.
Right now, the drug, called tisagenlecleucel (Kymirah), is only approved for children and young adults up to age 25 with B-cell ALL who haven’t gotten better with other treatments. But scientists are working on a version of CAR T-cell therapy for adults and for other kinds of cancer.