Key Points for This Section

Once childhood ALL has been diagnosed, tests are done to find out if the cancer has spread to the central nervous system (brain and spinal cord), testicles, or to other parts of the body. There are three ways that cancer spreads in the body. In childhood ALL, risk groups are used instead of stages.

Once childhood ALL has been diagnosed, tests are done to find out if the cancer has spread to the central nervous system (brain and spinal cord), testicles, or to other parts of the body.

The extent or spread of cancer is usually described as stages. For childhood acute lymphoblastic leukemia (ALL), risk groups are used instead of stages. The following tests and procedures may be used to determine the risk group:

• Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• Testicular biopsy: The removal of cells or tissues from the testicles so they can be viewed under a microscope by a pathologist to check for signs of cancer. This procedure is done only if there seems to be anything unusual about the testicles during the physical exam.

There are three ways that cancer spreads in the body.

When cancer cells spread outside the blood, a solid tumor may form. This process is called metastasis. The three ways that cancer cells spread in the body are:

• Through the blood. Cancer cells travel through the blood, invade solid tissues in the body, such as the brain or heart, and form a solid tumor.
• Through the lymph system. Cancer cells invade the lymph system, travel through the lymph vessels, and form a solid tumor in other parts of the body.
• Through solid tissue. Cancer cells that have formed a solid tumor spread to tissues in the surrounding area.

The new (metastatic) tumor is the same type of cancer as the primary cancer. For example, if leukemia cells spread to the brain, the cancer cells in the brain are actually leukemia cells. The disease is metastatic leukemia, not brain cancer.

In childhood ALL, risk groups are used instead of stages.

Risk groups are described as:

• Standard (low) risk: Includes children aged 1 to 9 years who have a white blood cell count of less than 50,000/µL at diagnosis.
• High risk: Includes children younger than 1 year or older than 9 years and children who have a white blood cell count of 50,000/µL or more at diagnosis.

It is important to know the risk group in order to plan treatment.

Glossary Terms

An aggressive (fast-growing) type of leukemia (blood cancer) in which too many lymphoblasts (immature white blood cells) are found in the blood and bone marrow. Also called acute lymphocytic leukemia and ALL.

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

The fluid that flows in and around the hollow spaces of the brain and spinal cord, and between two of the meninges (the thin layers of tissue that cover and protect the brain and spinal cord). Cerebrospinal fluid is made by tissue called the choroid plexus in the ventricles (hollow spaces) in the brain. Also called CSF.

An x-ray of the structures inside the chest. An x-ray is a type of high-energy radiation that can go through the body and onto film, making pictures of areas inside the chest, which can be used to diagnose disease.

The process of identifying a disease, such as cancer, from its signs and symptoms.

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.

A procedure in which a thin needle called a spinal needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called spinal tap.

A thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessel.

The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.

The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).

Having to do with metastasis, which is the spread of cancer from the primary site (place where it started) to other places in the body.

A part of the body that performs a specific function. For example, the heart is an organ.

A doctor who identifies diseases by studying cells and tissues under a microscope.

An exam of the body to check for general signs of disease.

The original tumor.

An abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancer), or malignant (cancer). Different types of solid tumors are named for the type of cells that form them. Examples of solid tumors are sarcomas, carcinomas, and lymphomas. Leukemias (cancers of the blood) generally do not form solid tumors.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone. The spinal column encloses the spinal cord and the fluid surrounding the spinal cord. Also called backbone, spine, and vertebral column.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

One of two egg-shaped glands inside the scrotum that produce sperm and male hormones. Also called testis.

A group or layer of cells that work together to perform a specific function.

A type of immune cell. Most white blood cells are made in the bone marrow and are found in the blood and lymph tissue. White blood cells help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are white blood cells. Also called leukocyte and WBC.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.