According to the Leukemia and Lymphoma Society, blood cancers such as leukemia and lymphoma make up 9.5 percent of all cancers diagnosed in the U.S. Leukemia is the No. 1 fatal cancer in individuals younger than age 20. For children younger than 15, lymphoma is the third most common cancer. Between 1996 and 2005, however, the risk of dying from these types of cancer decreased due to new treatment options.
Biology
Leukemia and lymphoma are cancers of the blood. These cancers begin in the bone marrow or lymph nodes, where blood cells are formed and stored. Because blood cells are being continually produced, a mutation that causes cancer in a single cell in the bone marrow or lymph nodes can quickly spread throughout the entire body via the bloodstream.
Types
There are four different types of leukemia. Acute myelogenous leukemia and chronic myelogenous leukemia both affect bone marrow cells that are precursors to red blood cells, plasma and some white blood cells. Acute lymphocytic leukemia and chronic lymphocytic leukemia occur in the precursor cells that would normally become lymphocytes---B or T white blood cells. Acute leukemias grow and spread rapidly, while the chronic types grow slowly over time. Lymphomas also affect lymphocytes, but they originate in the lymph system. Hodgkin's lymphoma contains a specific type of malignant cells while non-Hodgkin's lymphoma is subdivided into groups based on the specific characteristics of the cancer cells that develop from the lymphocytes.
Symptoms
In general, the early symptoms of leukemia or lymphoma appear harmless and are often mistaken for less serious diseases. Tiredness, persistent low-grade fever, swollen lymph nodes, unusual weight loss and shortness of breath may indicate the beginning stages of these diseases. As the disease progresses, night sweats, coughing, chest pain and persistent infections may appear as symptoms.
Tests
Blood cell counts are often the first indicator of potential leukemia or lymphoma. One major diagnostic test for leukemia and lymphoma is the B-cell leukemia/lymphoma panel, which looks at the proteins on the surface of the immune cells called B-lymphocytes. Abnormalities can indicate the existence of leukemia or lymphoma. A biopsy of the lymph nodes or bone marrow may be necessary to confirm the existence of lymphoma or leukemia.
Treatment
Chemotherapy, the use of anti-cancer drugs, remains the main treatment for leukemia and lymphoma. Radiation therapy using ionizing radiation may also be used for some cases of these blood cancers. Newer drugs used to fight lymphoma and leukemia include monoclonal antibodies that attack the cancer cells, tyrosine kinase inhibitors that block biochemical processes in cancer, immunomodulators that affect the immune system and drugs that affect methylation, the addition or removal of methyl groups on the cancer cell's DNA. Targeted therapies that aim the treatment at the cancer cell without affecting nearby healthy cells have made treatment for blood cancers more effective and have reduced side effects of treatment, explained Dr. Maria Baer in the Maryland Health Today Video Podcast sponsored by the University of Maryland Medical Center . A bone marrow transplant to replace the bone marrow stem cells that produce cancer cells is another treatment option for leukemia and lymphoma.
