Doctor's Notes on Leukemia
Leukemia is a general term for cancers (abnormal cells that multiply) of blood-forming immature cell types in the bone marrow that can spread into the blood and organs. Like many other diseases, the signs and symptoms of leukemias are non-specific; unexplained fevers, frequent infections, fatigue, easy bruising or bleeding, weight loss and night sweats. When leukemia cells aggregate in one or more organs, they may produce some of the following signs and symptoms: headache, confusion, seizures, balance problems, muscle control loss, blurry vision, swelling or nodules in the neck, armpits and/or groin, short of breath, nausea/vomiting, bone and joint pains and swelling and pain in the abdomen or testicles.
The exact cause of leukemia is not known. Associated risk factors for development include toxic exposures (like benzene), radiation exposure, smoking, previous chemotherapy, Human T-cell leukemia virus, myelodysplastic syndromes (blood cell abnormalities), genetics (abnormal genes and Down syndrome) and family history.
Symptoms usually develop fairly quickly in acute leukemias. Most cases of acute leukemia are diagnosed when the person visits his or her healthcare professional after becoming ill. Symptoms develop gradually in chronic leukemias and are generally not as severe as in acute leukemias. About 20% of people with chronic leukemia do not have symptoms at the time their disease is diagnosed and it is only a blood test which leads to the diagonsis.
Some symptoms of leukemia are due to deficiencies of normal blood cells. Others are due to collections of leukemia cells in tissues and organs. Leukemia cells can collect in many different parts of the body, such as the testicles, brain, lymph nodes, liver, spleen, digestive tract, kidneys, lungs, eyes, and skin -- in effect, virtually every tissue site.
The following symptoms of leukemia are common to all acute and some chronic types:
- Unexplained fevers
- Frequent infections
- Night sweats
- Fatigue (feeling tired or washed out)
- Weight loss
- Easy bleeding or bruising
Collection of leukemia cells in certain parts of the body may cause the following symptoms:
- Balance problems
- Blurred vision
- Painful swellings in the neck, under the arms, or in the groin
- Shortness of breath
- Nausea or vomiting
- Abdominal pain and/or swelling
- Testicular pain and/or swelling
- Pain in the bones or joints
- Weakness or loss of muscle control
It is important to emphasize that the symptoms of leukemia are nonspecific. This means that they are not unique to leukemia but are common to a number of diseases and conditions. Only a medical professional is able to distinguish leukemia from the other conditions that cause similar symptoms.
The exact cause of leukemia is unknown.
- As with other cancers, smoking is considered a risk factor for leukemia, but many people who develop leukemia have never smoked, and many people who smoke never develop leukemia.
- Long-term exposure to chemicals such as benzene or formaldehyde, typically in the workplace, is considered a risk factor for leukemia, but this accounts for relatively few cases of the disease.
- Prolonged exposure to radiation is a risk factor, although this accounts for relatively few cases of leukemia. Doses of radiation used for diagnostic imaging such as X-rays and CT scans are nowhere near as prolonged or high as the doses needed to cause leukemia.
Other risk factors for leukemia include the following:
- Previous chemotherapy: Certain types of chemotherapy, particularly certain of the alkylating agents and topoisomerase inhibitors, used to treat various types of cancers, are linked to development of leukemia later. It is likely that radiation treatment adds to the risk of leukemia associated with certain chemotherapy drugs.
- Human T-cell leukemia virus 1 (HTLV-1): Infection with this virus is linked to human T-cell leukemia.
- Myelodysplastic syndromes: This unusual group of blood disorders (formerly referred to as "preleukemia") is characterized by abnormal blood cell development and a highly increased risk of leukemia.
- Down syndrome and other genetic diseases: Some diseases caused by abnormal chromosomes may increase risk for leukemia.
- Family history: Having a first-degree relative (parent, brother, sister, or child) who has chronic lymphocytic leukemia increases one’s risk of having the disease by as much as four times that of someone who does not have an affected relative.
Leukemia is cancer of the blood cells. It shows up at about the same rate today as it did in the 1950s, but new treatments mean you can live with it longer than ever and sometimes be cured. While it's the most common cancer in children, more adults than kids get it. There are several types. Most start in white blood cells, but how they unfold and the treatment you need can be very different.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.