Once-lethal Leukemia is now curable

Leukemia, a cancer of the blood cells, primarily affects the bone marrow but, in many cases, doesn’t stop there: It can spread to other parts of the body and tissue and, if not treated, can continue to grow without warning.

Because it is common in children, leukemia is often thought of as a children’s cancer, but it can also affect adults.

Leukemia starts in the bone marrow, which is the soft tissue found inside most bones where blood cells are made.

The disease is characterized by the development of abnormal white blood cells in bone marrow. White blood cells are essential — they help immune systems fight infections and help cuts and sores heal faster — so when bone marrow begins to develop abnormal white blood cells, it, in turn, disturbs the immune system.

In a healthy body, red blood cells, white blood cells and platelets all develop in the bone marrow. Red blood cells carry oxygen to all parts of the body and remove carbon dioxide. Platelets are essential in forming clots when a blood vessel is damaged.

Under normal circumstances, these blood cells form, mature and carry out their intended functions before dying. This is a constant cycle where dead cells are constantly replaced by regenerated cells.

The problem in leukemia occurs when the bone marrow generates abnormal white blood cells. Unlike healthy white blood cells, they are of little or no use in fighting infection. They grow faster than the normal cells, linger longer and don’t stop growing when they should. In other cases, these leukemia cells can crowd out the normal blood cells and cluster over time, which leads to serious problems such as anemia, bleeding and infections. It can also spread to the lymph nodes (usually found in the underarms, groin, neck, chest and abdomen) or other organs.

This can lead to two different types of leukemia: chronic, which grows slowly over the years and often does not cause symptoms for years; and acute, which is the more rapid leukemia that gets worse very fast and causes symptoms right away. Acute leukemia can result in death in as little as a few weeks or months if it goes untreated, according to emedicinehealth.com.

The most common types of leukemia, according to the Leukemia and Lymphoma Society, are acute myelogenous leukemia (AML) and chronic lymphocytic leukemia (CLL), which are most often found in adults.

Acute lymphoblastic leukemia (ALL) is the type of cancer that is most often found in children. Although adults can also get ALL, ALL accounts for 65 percent of leukemia in children.

ALL and AML make up 85 percent of all leukemia cancer cases in children and leukemia is the cancer that kills the most of children and young persons under age 20.

"(Leukemia) is the most common malignancy in children," said Kevin Foon, M.D., head of the leukemia section at the Nevada Cancer Institute. "But in the past 40 years there has been amazing progress. At one time it was absolutely 100 percent lethal. Now it has become a curable disease."

Although children have a high rate of ALL and persons of any age can get leukemia, the Leukemia and Lymphoma Society states that leukemia is most common in people over the age of 60. In 2008, more than 44,000 adult and 4,000 children developed leukemia and it is estimated that it will kill almost 50,000 people this year. These cancers account for nearly 10 percent of all cancers, according to the Leukemia and Lymphoma Society.

The survival rate for leukemia is a mere 50 percent.

Treatment of kids with ALL has progressed mightily, Foon said.

"It’s hard to improve on. It has absolutely surpassed adult hematology/oncology. We could improve on treating very young kids, older kids and babies. The pediatric hematology/oncology community gets it," Foon said. "All kids will go into a research protocol."

Foon said few adults go into research protocols. Most are treated in the community where they live. Research protocols involving adults are labor-intensive and not cost-effective, Foon said.

Though the causes for leukemia are not known, some research suggests that smoking and exposure to chemicals such as benzene or formaldehyde may be linked to the disease, although many people with the disease don’t smoke.

Prolonged exposure to radiation can also be a factor for leukemia. Previous chemotherapy agents that usually treat cancer are linked to leukemia later. Down syndrome and other genetic diseases can also be a factor, as well as family history which can increase the risk of having leukemia by four times as much.

According to emedlineheath.com leukemia is also most common in people of European descent compared to blacks, Hispanics and Asians.

Because leukemia can cause white blood cells to form in parts of the body such as the testicles, brain, lymph nodes, liver, spleen, digestive track, kidneys, lungs, eyes and every part of the body with tissue, it can cause an array of symptoms.

All types of leukemia can cause unexplained fevers, frequent infections, night sweats, fatigue, weight loss and easy bleeding and bruising. The collection of leukemia cells in certain parts of the body causes headache, confusion, balance problems, blurred vision, painful swellings in the lymph nodes, shortness of breath, nausea or vomiting, abdominal pain or swelling, seizures and weakness or loss muscle control and joint pain.

Anyone who experiences these symptoms regularly should make an appointment with a primary care physician who could determine if the symptoms are caused by leukemia.

If a doctor suspects that a patient has leukemia, blood tests would be ordered.

Abnormal blood tests would result in a follow-up biopsy of the bone marrow. The samples of the bone marrow which are of the aspirate (liquid) and solid bone marrow are usually taken from the hip bone.

If it turns out that the patient does have leukemia, the doctors would run a variety of tests to determine which type of leukemia the patient has. Not all treatments work for all different types of leukemia, which is why it’s very important to run the follow-up studies.

The first test would be to check the chromosomes or genes to look for irregularities. It is also important to check for fluids surrounding the brain and the spinal cord, as this can have severe repercussions in the central nervous system. In order to check, doctors perform what is called a lumbar puncture or spinal tap, which consists of removing fluid from the area in the back at around the waist level using a hollow needle.

If the lymph nodes are expanded or swollen the doctor can also run a biopsy on the lymph nodes if the bone marrow does not provide enough information.

The most widely used form of treatment for leukemia is chemotherapy, which is the use of powerful drugs to kill the leukemia cells. Depending on the medication, the chemotherapy can either be administered by vein or mouth. Some patients will have an IV placed in the upper chest near the shoulder that is inserted into a large vein to administer the chemotherapy.

Those who have leukemia in their cerebrospinal fluid will receive chemotherapy directly into the cerebrospinal canal, what is known as intrathecal chemotherapy. This is important to do because sometimes drugs given by oral use or IV do not reach the brain and therefore cannot kill the leukemia cells.

The chemotherapy kills the cells and stops them from reproducing. Unfortunately it also will kill some healthy cells, which are some of the side effects to chemotherapy.

Hair loss and problems with the digestive system can be attributed to this.

Newer drugs and medications are constantly being developed to offset the negative side effects of chemotherapy; Gleevec is an example of the chemotherapeutic drug.

The chemotherapy is carried out for two to six cycles until all the bad cells have been killed.

Once this happens, the patient can be in remission.

Many doctors will consolidate and seek out and kill the residual leukemia cells not killed by induction.

The last step is to keep the disease in remission by administering much lower doses of chemotherapy for a while after.

After five years, patients who are still alive without a detectable disease will have an 80 percent chance to maintain lifelong remission.

In some cases clinical trials are also used to treat the cancer and in others the patients could use a bone marrow or cord blood transplant. This process replaces unhealthy blood forming cells with healthy ones. Sometimes patients can use their own blood-forming cells or the cells can be collected from someone else, depending on the situation. If patients need a transplant they can look for transplants from their families, however 70 percent of patients do not have a suitable donor in their family, according to marrow.org.

In this case the physician will go through a match registry of over 12 million volunteers worldwide who have submitted themselves as volunteer donors on a global listing.

Even then, chances are low, as there is only a 40 percent chance of finding a match through the donor registry and odds are much lower if the patient is an ethnic minority.

Even then, the chance that the body will reject the bone marrow are high.

In order to increase chances for a positive bone marrow match for a patient, a generous person can add themselves to the registry by signing up for the National Marrow Donor program at www.marrow.org. The life-saving donors never have to pay for the procedure and it is usually not very painful.

Research is continuing and there is reason to be hopeful. The most dramatic breakthroughs have occurred in the treatment of CLL.

"It’s the single most exciting story in cancer in the past 25 years," Foon said.

Brian Drucker, a researcher at the University of Oregon, championed a compound he had used to cure cancer in mice and pushed the company Novartis to license it. This eventually led to the development of the drug Gleevec, which had dramatic results.

"Patients with the disease take this pill and the disease goes away," Foon said. "It’s the kind of story that gives you chills."