Leukemia (leukaemia British English spelling) is a form of cancer that appears in the blood or bone marrow and is characterized by an abnormal increase of immature white blood cells. The term leukemia covers a wide spectrum of related diseases.
Leukemia itself is categorized as a hematological neoplasm, along with a number of other diseases that affect the blood, lymphoid system and bone marrow. The most common treatment for leukemia involves chemotherapy and medical radiation therapy, but hormone treatments are also used when treating leukemia. When people think of leukemia they tend to think of young children who are afflicted with this nasty disease, however 90% of all cases of leukemia are in adults. The good news is that with modern treatment children have a good chance of fully recovering. For adults who contract leukemia, the chances of survival aren’t as good as a child’s, but the success rate is still high compared to other more aggressive cancers.
There are a large number of classifications for leukemia, based on divisions on it’s severity and form. In terms of severity, there is acute leukemia and chronic leukemia.
Acute Leukemia manifests in a huge increase in the number of immature blood cells. Those cells crowd the bloodstream and the bone marrow is unable to produce healthy blood cells. This form of leukemia has a rapid progression and malignant cells can rapidly spread through the bloodstream into other organs. Acute leukemia is the type most commonly found in children.
Chronic Leukemia manifests in a buildup of mature white blood cells that are still abnormal. The abnormal white blood cells are produced at a fast rate, taking months or years to build up. This form of cancer takes longer to build up so doctors can sometimes wait until the buildup has reached a certain point to get the most effectiveness from available treatment methods. This form of cancer occurs in people of all ages, but mostly in older people.
Leukemia is also categorised according to the type of blood cell that is being affected, lymphocytic leukemias and myelogenous leukemias.
Lymphocytic Leukemias involve a cancerous change in the marrow cell that forms lymphocytes. Lymphocytes are infection fighting cells within the immune system.
Myelogenous Leukemias, sees a cancerous change in the marrow cells that go on to form red blood cells and some kinds of white blood cells.
Drilling further down, underneath these 4 main categories there are numerous subcategories which deal with specific variations of leukemia. Some of the more common variations of leukemia include:
Chronic lymphocytic leukemia (CLL) which affects mostly older people (generally over 55) and very rarely affects children. Affects mostly men and has a 5 year survival rate of 75%. This an aggressive form of leukemia, is incurable and has a subtype called B-cell prolymphocytic leukemia, an even more aggressive disease.
Acute lymphoblastic leukemia (ALL) is the most common form of leukemia contracted by children however it can also be contracted by young adults and even older adults over 60. Luckily this form of leukemia responds well to chemotherapy and radiotherapy treatment with 85% survival rates for children and 50% survival rates for adults.
Chronic myelogenous leukemia (CML) again occurs mainly in adults and rarely in children. The most common treatment is a drug called Gleevec (or Glivec in some countries) and it has a very high 90% 5 year survival rate.
Acute myelogenous leukemia (AML) is mainly found in adults and is more common in males. AML has a 5 year survival rate of 40% and is treated with chemotherapy. Subtypes of AML include acute promyelocytic leukemia, acute myeloblastic leukemia, and acute megakaryoblastic leukemia.
Adult T-cell leukemia is actually caused by a virus called T-lymphotropic virus (HTLV) which shares some similarities to HIV. HTLV infects CD4+ T-cells and replicates within them giving those infected cells a lot of strength and helps them propagate in huge numbers.
Hairy cell leukemia (HCL) is considered a subset of chronic lymphocytic leukemia, but has a number of difference to CLL. It mostly affects adult men, with 80% of HCL cases being male, and no cases of it affecting children have been reported. The disease is incurable but easily treated with a survival rate of over 90%
T-cell prolymphocytic leukemia (T-PLL) is one of the most aggressive forms of leukemia but is thankfully rare. This form affects mostly adult males, and rarely children. It affects mature T cells while nearly all other leukemias involve B cells. It is very difficult to treat and has a high mortality rate and survival time is usually measured in months.
Symptoms of Leukemia
Because leukemia damages the bone marrow due to the high numbers of immature white blood cells that are created, the blood clotting process is affected. That means that common signs of leukemia include being bruised easily, bleeding excessively and developing pinprick bleeds (tiny pin-prick haemorrhages that show on the skin after minor trauma).
Because the white blood cells are immature and malformed, the immune system may be greatly impaired. So if a person exhibits problems fighting off simple infections, leukemia may be the root cause. That can be re-occurrence of simple skin infections, oral infections or being unable to combat the simple cold. If the infection is one that most people usually fight off in days, but it lingers for weeks or months, leukemia could be the root cause because it is suppressing your immune system.
The red blood cell deficiency tht comes with leukemia also leads to anemia, and all of the related problems caused by that.
There are various other symptoms reported by leukemia sufferers, ranging from an overall feeling of being constantly rundown, to constant fatigue, symptoms similar to the common cold, night sweats and fevers. Patients have also reported nausea which is caused by the impact of leukemia on the liver and spleen.
In cases where the leukemia cells have invaded the central nervous system, some patients report headaches as a common symptom. Unfortunately many of the symptoms associated with leukemia can be attributable to many different kinds of illnesses so it’s often difficult to detect until the correct tests are done.
Using a blood sample, leukemia is usually very easily spotted due to the large amount of white blood cells found in the sample. Usually many of those cells are malformed or dysfunctional, so physicians can also check the condition of white blood cells.
However in some cases leukemia patients do not have a high white blood cell count that can be seen in a regular blood test, that condition is called aleukemia. The bone marrow still contains cancerous white blood cells but they remain in the marrow instead of entering into the bloodstream in great quantities.
There are multiple possible causes for the various forms of leukemia and research continues to help us understand the reasons for this illness. At this point we understand some of the possible causes for some forms of leukemia, but for many forms of leukemia we are still trying to understand what was the root cause.
Mutations in the DNA are thought to be responsible for many forms of leukemia. Research has shown that mutations can trigger leukemia by deactivating tumor suppression genes which allows the mutations to occur. DNA mutations can occur because of exposure to hazardous chemicals or radiation. Some of the chemicals include benzene and even alkylating chemotherapy agents that may have been used to treat previous cancers.
Viruses like the T-lymphotropic virus can cause leukemia n adults. Other possible chemical causes include tobacco, petrochemicals and even some chemical hair dyes.
According to research, whilst helping prevent some other forms of cancer dramatically, eating a healthy diet has little effect on leukemia.
There are a wide variety of techniques which are used to treat leukemia and because the illness manifests in so many different ways, only certain treatment methods may be of use for certain forms of the disease.
High dose chemotherapy is one of the most commonly used treatments for leukemia and has proven very successful in many forms of the illness. Radiotherapy is also used to treat certain forms of leukemia.
Bone marrow transplantation treatments may also be used in some instances to help remove marrow that has been affected by the leukemia and to help the patient generate healthy blood cells.
Cancer drugs like Gleevec have also been used with great success in treating certain forms of leukemia. With advances in modern technology, leukemia survival rates have greatly improved and the outlook is good for most leukemia patients.