Acute Lymphoblastic Leukemia (ALL): What to Know

This page is for adults newly diagnosed with ALL and their families. It explains the name, the first tests, the phases of treatment, and options if the leukemia comes back.

Each of the three words tells you something.

Acute means the cells are immature and multiply fast. NCI says ALL usually gets worse quickly if it is not treated. That is why treatment planning starts promptly.

Lymphoblastic points to the cell of origin. A lymphoblast is an early lymphocyte, a type of white blood cell that is part of the immune system. In ALL, these blasts get stuck in their immature form. They pile up in the marrow and crowd out red cells, platelets, and normal white cells.

Leukemia means the disease lives in the blood and marrow rather than forming a lump.

ALL is uncommon overall, but it is the most typical leukemia of childhood. The American Cancer Society projects about 6,250 new US cases and 1,600 deaths for 2026 (Cancer Facts & Figures 2026). SEER's own measurements put the median age at diagnosis at 18 and the median age at death at 60. That gap points to something important: outcomes are much better in children and young adults than in older adults.

Diagnosis usually starts with an abnormal complete blood count. It may show low red cells, low platelets, and a white count that is very high or very low. Blasts often show up when the blood is looked at under a microscope (a blood smear).

Then comes a bone marrow aspirate and biopsy, usually from the back of the hip bone. That sample goes for several separate tests:

• Flow cytometry reads the proteins on the cell surface and sorts B-cell ALL from T-cell ALL.
• Cytogenetics looks at whole chromosomes for changes such as the Philadelphia chromosome or the t(4;11) translocation.
• Molecular testing looks at specific genes, including BCR::ABL1.
• A lumbar puncture samples spinal fluid to see if the leukemia has reached the brain and spinal cord.

Ask which of these are back and which are pending. The chromosome and gene results can change the plan.

When many leukemia cells die quickly, uric acid in the blood can rise. This is part of tumor lysis syndrome.

Your team may use a drug such as rasburicase (Elitek) to manage uric acid. The FDA label says it must not be used in people with G6PD deficiency (an inherited enzyme condition), because it can cause severe red cell breakdown. The label says people at higher risk, such as those of African or Mediterranean ancestry, should be screened first.

Oncologists call the brain and spinal cord a sanctuary site. That means a place where leukemia can hide. Most chemotherapy given by vein does not reach the spinal fluid well. Leukemia cells in that space can survive treatment and come back later.

So ALL treatment includes central nervous system (CNS) preventive therapy. NCI says it is usually given during each phase of treatment. It can include:

• Intrathecal chemotherapy, such as methotrexate, placed directly into the spinal fluid.
• High-dose chemotherapy given through the body (systemic) that reaches the fluid.

Radiation to the head (cranial radiation) is still used in some cases.

Treatment is divided into three phases:

• Remission induction
• CNS (central nervous system) preventive therapy
• Consolidation and maintenance

Total treatment length averages 1.5 to 3 years.

That length surprises people. Ask your team what each phase involves. Ask before stopping or skipping any part of it.

Growth factors are drugs that help the marrow make blood cells. Using them during induction appears to shorten the time until blood counts recover.

The Philadelphia chromosome is a swap between chromosomes 9 and 22. It joins two genes into one, called BCR::ABL1. The joined gene makes an enzyme that is always switched on and drives cell division. It gets more common with age, which is one reason older adults with ALL have done worse.

It is also treatable in a specific way. Tyrosine kinase inhibitors, taken as pills, switch that enzyme off. Ask your team which treatments fit your situation, and ask whether your leukemia has the Philadelphia chromosome.

NCI names the Philadelphia chromosome and the t(4;11) change as linked to a poorer outlook. Ask your team what your test results mean for your plan.

Options after relapse now include several targeted immune drugs.

Blinatumomab links a T cell to a CD19 protein on the leukemia cell so the T cell kills it.

Inotuzumab ozogamicin is an antibody carrying a toxin to CD22.

Tisagenlecleucel (Kymriah) is a CD19-directed CAR T-cell therapy. Your own T cells are collected, engineered, and given back. The FDA label covers patients up to 25 years of age whose B-cell ALL is refractory or in second or later relapse. Ask your team whether it fits your situation.

NCI lists blinatumomab and inotuzumab ozogamicin as options followed by an allogeneic (donor) stem cell transplant.

Call 911 or go to the nearest emergency department for:

• Bleeding that will not stop, black or tarry stool, or vomit that is bloody or looks like coffee grounds.
• Confusion, a seizure, or being hard to wake.
• Chest pain, or trouble breathing at rest.
• Sudden inability to pass urine at all.

Call your care team right away, day or night, for:

• Temperature of 100.4°F (38°C) or higher, or shaking chills. The CDC says a fever during chemotherapy means calling your doctor right away.
• A sore throat, mouth sores, burning when you pass urine, or any other sign of infection. Call even if your temperature is normal.
• A new rash of tiny red dots, blood in the urine, or sudden swelling.
• A severe new headache.

If you cannot reach your team quickly, go to the emergency department and say you are in leukemia treatment.

Leukemia, Blood and Marrow Stem Cell Transplant, CAR T-Cell Therapy, and What Does Minimal Residual Disease Mean.

• https://www.cancer.gov/types/leukemia/hp/adult-all-treatment-pdq
• https://seer.cancer.gov/statfacts/html/alyl.html
• https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0ae10bc4-6b65-402f-9db5-2d7753054922
• https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aad3ba54-dfd3-4cb3-9e2b-c5ef89559189
• https://www.cdc.gov/cancer-preventing-infections/patients/fever.html
• https://www.cancer.gov/types/leukemia/patient/adult-all-treatment-pdq
• https://www.cancer.org/cancer/types/acute-lymphocytic-leukemia/about/key-statistics.html