Leukemia: Early detection a key to recovery

By Rita A. Widiadana

SINGAPORE (JP): No one wants to suffer from a serious disease, especially one that is a form of cancer. But if you are diagnosed with such, there are new drugs and therapy which will help minimize your hardship.

Dr. Freddy Teo Cheng Peng, a noted oncologist at Gleneagles Hospital in Singapore, shared his know-how on leukemia or cancer of the blood.

The doctor said leukemia is one of more than 100 types of cancers.

Leukemia is a cancer of the blood cells and is considered to be the number one cancer which kills children.

According to a study done by the Maryland chapter of the Leukemia Society of America, children are ten times more likely to contract leukemia than adults. But with the best treatment, 72 percent of children diagnosed with childhood leukemia may survive. The overall survival rate has doubled in the last 30 years.

"To understand leukemia, it is helpful to know about normal blood cells and what happens to them when leukemia develops," the doctor said.

The blood is made up of a fluid called plasma and three types of cells. Each type has a special function.

White blood cells, which are also called leukocytes, help the body fight infections and other diseases.

Red blood cells, also called erythrocytes, carry oxygen from the lungs to the body's tissues and take carbon dioxide from the tissues back to the lungs.

Platelets, which are also called thrombocytes, help form clots to control bleeding.

Blood cells are formed in the bone marrow, the soft, spongy center of bones. New (immature) blood cells are called blasts. Some blasts stay in the marrow to mature, while some travel to other parts of the body to mature.

Normally, blood cells are produced in an orderly, controlled way as the body needs them. This process helps keep us healthy.

When leukemia develops, the body produces large numbers of abnormal blood cells. In most types of leukemia, the abnormal cells are white blood cells. Leukemia cells usually look different from normal blood cells, and they do not function properly.

Dr. Peng explained that until now the cause of leukemia or other cancer diseases was not yet known. There are some risk factors, such as exposure to large amounts of high energy radiation. Certain genetic conditions can also increase the risk of leukemia. Children with Down's Syndrome are more likely to get leukemia than other children.

Workers or people exposed to certain chemical substances like benzene over a long period of time are at a higher risk of leukemia.

The U.S.-based National Cancer Institute categorized several types of leukemia.

Leukemia is either acute or chronic. In acute leukemia, the abnormal blood cells are blasts that remain very immature and cannot carry out their normal functions. The number of blasts increases rapidly, and the disease gets worse quickly.

In chronic leukemia, some blast cells are present, but in general, these cells are more mature and carry out some of their normal functions. Also, the number of blasts increases less rapidly than in acute leukemia. As a result, chronic leukemia gets worse gradually.

These are the most common types of leukemia:

Acute lymphotic leukemia (ALL) is the most common type of leukemia in young children. This disease also affects adults, especially those aged 65 and older.

Acute myeloid leukemia (AML) occurs in both adults and children. This type of leukemia is sometimes called acute nonlymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) most often affects adults over the age of 55. It sometimes occurs in young adults, but it almost never affects children.

Chronic myeloid leukemia (CML) occurs mainly in adults. A very small number of children also develop this disease.

Symptoms

Leukemia cells are abnormal cells that cannot do what normal blood cells do. They cannot help the body fight infections.

"Listen to your body and be careful if your children have these symptoms," explained Dr. Peng.

Some of the common symptoms of leukemia are a fever, chills, flu-like symptoms, weakness and fatigue, frequent infections and a loss in appetite.

Other symptoms are swollen or tender lymph nodes, liver or spleen, easy bleeding and bruising and tiny red spots.

To find the cause of a person's symptoms, the doctor asks about the patients' medical history and does a physical exam.

Blood tests also help in diagnosis. A sample of blood is examined under a microscope to see what the cells look like and to determine the number of mature cells and blasts. Although blood tests may reveal that a patient has leukemia, they may not show what type of leukemia it is.

To check further for leukemia cells or to determine what type of leukemia a patient has, a hematologist, oncologist or pathologist examines a sample of bone marrow under a microscope.

"Treatment for leukemia is complex and expensive," said the doctor. It varies with the type of leukemia and is not the same for all patients. It depends on the patient's age, symptoms and general health.

Acute leukemia needs to be treated right away. Many people with acute leukemia can be cured.

Chronic leukemia patients who do not have symptoms may not require immediate treatment. However, they should have frequent checkups so the doctor can see whether the disease is progressing. Chronic leukemia can seldom be cured.

"There are several types of treatment for leukemia," he said.

Chemotherapy is the use of drugs to kill cancer cells. It is given in cycles: a treatment period followed by a recovery period, then another treatment period and so on. Radiation therapy is used along with chemotherapy for some kinds of leukemia.

A bone marrow transplant may be used for some patients. The patient's bone marrow producing leukemia is destroyed with a high dose of drugs and radiation and is then replaced by healthy bone marrow. The healthy bone marrow may come from a donor, or it may be marrow that has been removed from the patient and stored before the high-dosage treatment.

Biological therapy involves treatment with substances that affect the immune system's response to cancer.

Dr. Peng acknowledged that it was difficult to avoid possible side effects from these treatments.

"Each person reacts differently. Side effects may even be different from one treatment to the next," he said.

The side effects of chemotherapy, for instance, depend mainly on the drugs the patients receive. Cancer cells divide more often than healthy cells and are more likely to be affected by chemotherapy. Some healthy cells also may be damaged.

Radiation therapy also has side effects. Patients receiving radiation therapy may become very tired, lose their hair, experience nausea, vomiting and a loss of appetite. Children, especially younger ones, who receive radiation to the brain may develop problems with learning and coordination.

"Despite these effects, early treatment and therapy may save the lives of cancer patients," Dr. Peng said.

Dr. Freddy Teo Cheng Peng can be reached at Gleneagles Hospital by phoning 65-473722 or faxing 65-47251816. Questions can be sent through san-san-tan@gleneagles.com.sg.

More information on leukemia can be obtained from the Cancer Net at http://cancernet.nci.nih.gov/wyntk-pubs/leukemia.htm.