Adult T-cell leukemia (ATL) is a rare type of cancer that develops in immune t-cells. ATL is caused by human t-cell leukemia/lymphoma virus type 1, or HTLV-1. This cancer is aggressive, and most patients die within one year of diagnosis. Adult t-cell leukemia is a form of non-Hodgkin's lymphoma. ATL affects adults, and is most common in the Caribbean and Japan. It is noted in less frequent clusters in Western countries.
HTLV-1, the virus responsible for ATL is a retrovirus. It can be transmitted through blood, such as shared needles or a blood transfusion, sexual contact, or from mother to child. The latency period for developing adult t-cell leukemia after exposure to HTLV-1 is an average of 30 years. Less than five percent of people who are carriers of HTLV-1 develop ATL.
Visible symptoms of adult t-cell leukemia include skin lesions and enlarged lymph nodes. Other symptoms include an increased susceptibility to infections, high levels of blood calcium, bone lesions and an enlarged liver and spleen. There are four sub-types of the illness, acute and lymphomatous, which both grow very quickly, and less aggressive smoldering and chronic ATL.
Symptoms develop rapidly in acute ATL. The patient typically experiences enlarged lymph nodes in the groin, armpit and neck, fatigue, skin rash, and elevated levels of calcium in the blood, which can lead to severe constipation and an irregular heartbeat. Lymphomatous ATL is confined to the lymph nodes. Chronic ATL progresses slowly, and symptoms include enlarged lymph nodes as well as enlarged organs such as spleen and liver, as well as skin rash and fatigue. Smoldering ATL progresses very slowly and presents mild symptoms such as lesions on the skin.
Diagnosis of adult t-cell leukemia is made by biopsy. The healthcare provider will view abnormal skin tissue or tumor tissue through a microscope to make a diagnosis. He or she may also perform a blood test to measure levels of calcium in the blood, as well as white blood cell counts. Once a diagnosis is made, the doctor may order a CT scan of the spleen, liver, chest, and abdomen as well as a bone marrow biopsy to determine the extent of the illness.
Because adult t-cell leukemia is relatively rare, it is difficult to conduct clinical trials to develop a recommended treatment protocol. Standard treatment for ATL is similar to other forms of t-cell lymphoma, which is a combination of chemotherapy drugs. Patients may also take antiviral medication and interferon to treat the HTLV-1 infection. Some healthcare providers recommend bone marrow transplants for patients that enter remission.