About Blood Cancers

Blood cancers are classified as "hematological malignancies," or cancers that affect the blood, bone marrow and lymph nodes. Because each of these bodily systems is closely connected through the immune system, cancer of one area often spreads to the other two. Blood cancer involves the uncontrolled growth of abnormal cells in the blood.

About Blood Cancer

In 2008, approximately 138,000 new cases of blood borne cancers were diagnosed in the United States. Cancers of the blood affect both children and adults, although risk increases with age. Men are more likely to develop blood cancers than women. The three main types of blood cancers are:
  • leukemia
  • lymphoma
  • multiple myeloma.
Other rare blood cancers include myelodysplastic syndrome and myeloproliferative disorders.
 
The exact causes of cancers of the blood are still unknown. Some possible risk factors include exposure to:
  • asbestos
  • benzene
  • excessive radiation
  • pesticides.
Experts recommend wearing protective clothing and gloves when coming into contact with these hazardous chemicals to reduce the risk of developing cancers of the blood.
 
Research has also determined that some cases of blood cancer arise due to inherited mutations in genetic material.

The Biology of Leukemia

Leukemia is a cancer that affects the blood-making systems of the body, including the bone marrow and the lymphatic system. Leukemia usually infects granulocytes or lymphocytes, the two major types of white blood cells. White blood cells are made in the bone marrow and help the immune system fight off infections and foreign organisms. People of all ages can develop leukemia; however, it is most common in elderly people. Children who develop leukemia most often experience onset before the age of 10.
 
Leukemia can be either acute or chronic. In patients with acute leukemia, immature blood cells reproduce too quickly, crowding out healthy cells. Sometimes the diseased cells spread to other organs of the body. Chronic leukemia causes the production of large numbers of partially developed blood cells that are unable to function as mature blood cells should.
 
Often, early symptoms of leukemia are similar to other common illnesses, such as flu. Symptoms may include:
  • bleeding or swollen gums
  • bone or joint aches
  • enlarged spleen or liver
  • fatigue
  • feeling of abdominal fullness
  • fever
  • frequent bruising
  • frequent infections
  • headache
  • nosebleeds
  • skin rash
  • slow-healing cuts
  • swollen lymph nodes
  • unexplained weight loss.

The Biology of Lymphoma

Lymphoma is a cancer of the lymphocytes, which are white blood cells involved with defending the body against infection. Lymphoma causes the lymphocytes to grow at an uncontrolled rate. In addition to environmental hazards, risk factors for lymphoma may also include genetics and exposure to certain infections.
 
Usually lymphoma begins in one of the body’s lymph nodes. It can also sometimes begin in other organs containing lymphocytes, including the intestines, skin or stomach. The major forms of lymphoma are Hodgkin’s disease and non-Hodgkin’s lymphoma.
 
Hodgkin’s disease affects about five in every 100,000 people, and is most common in adults in their late 20s or those past 50 years of age. Caucasians are most at risk.
 
Non-Hodgkin’s lymphoma affects about 16 people per 100,000. Usually occurring in people between 60 and 70 years of age, it can also be found in children and young adults. This disease affects more people of Caucasian ancestry than any other ethnicity. 
  • Symptoms of lymphoma include:abdominal pain
  • difficulty swallowing
  • fever
  • itchy skin
  • night sweats
  • painless swelling of lymph nodes in armpits, groin or neck
  • rash
  • unexplained weight loss.

The Biology of Multiple Myeloma

Multiple myeloma is a blood cancer affecting five to six people per 100,000. A cancer of the plasma cells, it most often occurs in those over the age of 65. People of African descent have the highest risk for developing multiple myeloma, and Asians the lowest.
 
People with multiple myeloma experience uncontrolled growth of abnormal plasma cells produced in the bone marrow. Rather than forming a tumor, these cancer cells are most often found dispersed throughout the body in the blood and bone marrow. Sometimes, however, lymphoma can produce a tumor in the bone or soft tissues of the body.
 
Symptoms of multiple myeloma include:
  • bone pain (frequently in lower back or ribs)
  • fatigue and weakness
  • frequent infections
  • kidney problems causing constipation, increased urination, nausea and thirst
  • unexplained weight loss
  • weakened and broken bones.

Treatments for Blood Cancer

Over the past 30 years, treatments for blood cancers have become much more effective, actually doubling the survival rate. Statistics for some individual conditions are even more dramatic. For example, in 1960, a child diagnosed with childhood leukemia had only a 4 percent chance of survival. Today, childhood leukemia patients have a 79 percent chance of beating this once-fatal disease. Major treatments for blood cancers include:
  • Biological therapy: This involves using special immune system cells and proteins to stimulate the body's own immune system to kill the cancer cells.

  • Bone marrow transplants: High doses of chemotherapy and radiation kill both the healthy and cancerous cells in the bone marrow. The patient is then given an infusion of healthy stem cells from a bone marrow or blood donor.

  • Chemotherapy: During chemotherapy, doctors administer medications to kill off cancer cells. Treatment may include dexamethasone coupled with thalidomide for blood cancers such as multiple myeloma.

  • Radiation: This treatment targets localized cancerous areas in the body to kill cancer cells or shrink problematic tumor growth. Targeted areas of the body are exposed to high levels of radiation, which can kill off cancerous cells. 
Resources
 
Aetna InteliHealth, Inc. (2009). Overview of blood cancer. Retrieved February 17, 2009, from the Aetna InteliHealth.com Web site: http://www.intelihealth.com/IH/ihtIH/WSIHW000/8096/8514/188468.html?d=dmtContent.
 
The Leukemia & Lymphoma Society (LLS). (2007). Other blood cancers. Retrieved February 17, 2009, from the Leukemia & Lymphoma Society Web site: http://www.leukemia-lymphoma.org/all_page.adp?item_id=274059.