Leukaemia is a cancer of the blood.  New blood cells are continally produced in the bone marrow (in the bones).  Stem cells are the immature cells in the bone marrow which grow into different types of cells in the body, including blood.  From the early stage of being a stem cell, the cells grow and mature into functional cells.  As a result of the genetic changes to the DNA in the cell, they often stay as immature cells or cells that are now defective.  This means that the cell cannot perform its function properly, and the defective cells start increasing in number in the blood and normal cells decrease.  These damaged cells are called malignant cells, which means they are cancerous.

There is no clear explanation as to why this happens, but there are some causes that seem to be specific to the type of leukaemia.  The different types of leukaemic are characterized by whether they are acute (fast growing) or chronic (slow growing).  These cancers are also classified into lymphocytic or meyloid leukaemias, which is determined by where these abnormal cells are produced in the bone marrow.

The specialists that treat blood cancers are called Haematologists.  You will be referred by your GP to these specialists.  There are differnt procedures and tests that are done to diagnose leukaemia, including blood tests (pathology), bone marrow biopsy, CT and MRI scans, and other tests.

Treatment options are different depending on the type of leukaemia you have.  The most common treatments include chemotherapy, biological and targeted drugs, stem cell transplant, radiation, platelet transfusion and other medications.

Acute Lymphocytic Leukaemia (ALL)

This type of leukaemia is most common in childhood (2-5year) and represents almost 25% of cancer among children.  The child can be born with this leukaemia, or develop it after birth.  ALL can be caused by exposure to radiation, certain chemicals or with certain genetic conditions (e.g. Downs Syndrome).  There is a rapid onset of the disease, and this means that there are large numbers of very immature white blood cells in the blood.

Some patients will have a better response to treatment, depending on the subtype of ALL and other factors.  Total treatment takes about two years, and chemotherapy will usually be given first to achive a remission. Different combinations of chemotherapy drugs can be used.  The first month of treatment can be quite disruptive, as it requires frequent visits to the Haematologist and potentially time in the hospital for infections.  Most patients are able to achieve remission at this stage, but because these cancer cells might be lurking elsewhere in the blood, more treatment may be needed.  If the patient does go into remission, a short course of chemotherapy will follow using the same drugs as in the first treatment.  However, some patients might still be at a risk of relapse, and it would be at this stage that a stem cell transplant might take place, expecially if the patient has a sibling who would be a good donor match. After this procedure more chemotherapy can be given, depending on how the patient has responded to the first treatment.

Acute Myeloid Leukaemia (AML)

AML is a cancer caused by the rapid growth of abnormal white blood cells that accumulated in the bone marrow and interfere with the production of normal blood cells.  This is the most common acute leukaemia in adults and there are several subtypes of AML.  The chances of getting AML increases with age. As this is an acute leukaemia, it can progress rapidly and therefore must be treated as soon as possible. New research into the genetics of AML has resulted in better understanding of which treatment to use for each patient.

The causes of AML are not clear, but can sometimes be due to a congenital disorder (Downs Syndrome), exposure to radiation, exposure to certain chemicals or genetics (close family members).  There is a potential link to other blood disorders that may be present before the diagnosis of AML (Myelodysplastic syndrome or myeloporliferative disease). The treatment options include chemotherapy to induce remission and/or stem cell transplant.

Chronic Myeloid Leukaemia (CML)

This type of leukaemia is a cancer of the white blood cells that have accumulate in the blood.  This cancer is more common in adults. CML is linked to a genetic abnormality where there is an abnormal gene called the Philadelphia chromosome that is present in the cells of the blood.  Treatment has become tailor made for CML, as the new drugs on the market target this chromosome.  This means that these new targeted drugs (which are not chemotherapy), can be more effective and have dramatically improved the survival of patients with this disease.  These drugs have less side effects and the patient has a better quality of life than if they had been given conventional chemotherapy.

Chronic Lymphocytic Leukaemia (CLL)

CLL is a cancer of the blood which is as a result of the bone marrow making too many white blood cells.  These white blood cells have defects in the DNA and new cells include the defective DNA, resulting in CLL.  It is the most common type of leukaemia in adults over the age of 50, and the older the patient, the higher the chance of getting this disease. The causes may be hereditary, age, gender (more common in men) and exposure to certain chemicals.  As it is a slow growing, chronic disease, it is often not picked up for many years, as the patient does not notice symptoms relating to CLL.  Therefore it is often picked up at a routine medical examination where blood is taken and tested.  Early stage CLL is not treated, but as the symptoms become more apparent, treatment will begin.  The treatments used for CLL are chemotherapy, biological and targeted drugs, radiation and surgery of affected organs (e.g. spleen).

Lymphoma is a cancer of the lymphatic system.  The lymphatic system is part of the immune system and fights off infection.  The system consists of thin tubes that connect with the lymph nodes (glands) throughout the body.  The tubes carry fluid called lymph that moves through the lymphatic system and then to the blood.  A lymph node is about the size of a pea and contains a large number of lymphocytes (type of white blood cell).  These cells divide and the new cells are abnormal.  The disease appears as a solid tumour (not liquid like blood) in the lymph nodes of the neck, chest, armpits and groin.

Other organs that are part of the lymphatic system are the bone marrow, spleen, thymus and tonsils.  The treatment of lymphoma depends on the type and the health and age of the patient.  Lymphoma can be treated by a Haematologist, and some Oncolgists also treat this disease.

Lymphoma is divided into two types:  Non-Hodgkin and Hodgkin Lymphoma

Non-Hodgkin Lymphoma (NHL)

NHL is a disease of the lymphatic system where the white blood cells do not work properly and the immune system is weakened.  This disease is known to be unpredictable in the way it spreads through the lymphatic system and there are 35 types of NHL. 

You tend to see NHL in people over the age of 65, but it can occur in younger people.  The glands swell up in the neck, groin and/or underarms, as this is where the cancer is formed.  NHL could be linked to a genetic problem, or caused by viruses or bacteria that get into the immune system.  One of the viruses that can cause NHL is the Epstein-Barr virus, but it does not mean that if you have the virus you will get NHL.  This disease can also be caused by exposure to radiation or certain chemicals. 

Treatment will depend on the type of NHL, whether the disease is slow or fast growing, the stage and the general health of the patient. Treatment options include:  radiotherapy, chemotherapy, targeted and biological medications and stem cell transplant.

Hodgkin Lymphoma (HL)

HL is a cancer of the lymphatic system, and new white blood cells are formed with a defect.  These cells accumulate in the lymph nodes (glands) and form a solid tumour here.  The defected cancer cell that causes HL is called the Reed-Sternberg cell, which can be seen under the microscope. 

This lymphoma is more common in teenagers and young adults from the age of 15-35.  It can develop as a result of a genetic defect, exposure to radiation or certain chemicals or a virus that has damaged the immune system.  The most common virus that can cause HL is called the Epstein-Barr virus, but it does not mean that if you have the virus you will get NHL.  50% of patients with HL will have had this viral infection. 

Treatment options include chemotherapy, biological and targeted drugs, and radiation therapy.

Multiple Myeloma is a cancer of the plasma cells (fluid) of the blood.  The cells of the plasma divide and form genetically damaged cancer cells.  These defected cells accumulate in the bone marrow and form tumours in the bones of the body.  This disease is mostly found in patients over the age of 60, but can also be found in younger patients.  It is not clear what causes this disease, but it can be hereditary (from a brother or sister who has MM), or from being exposed to radiation.  The type of treatment depends on the individual patient, and how much the disease has spread.  Treatment options include chemotherapy, biological and targeted drugs and radiation therapy.

Haemophilia is an inherited condition that affects the blood’s ability to clot (called coagulation). It is caused by a genetic mutation that may have occurred spontaneously in earlier generations. People living with the condition have fewer clotting factors in their blood than usual, and therefore can bleed more frequently and for longer periods than those without the condition. They also bruise more easily than normal.

Haemophilia usually only occurs in males, although there is a small chance of a girl being born with haemophilia if both parents carry the haemophilia gene. The haemophilia gene is, however, usually carried by women and although they don’t develop the condition themselves, they may also suffer from some bleeding problems such as abnormally heavy periods. Symptoms can range from mild to severe, depending on the level of clotting factors in the individual’s blood. 

In mild cases, symptoms may only present after something like an injury, a dental procedure or surgery. In moderate cases, there may also be frequent bruising and bleeding around the joints from early childhood, and this can cause both severe pain and deformation of the joints. In severe cases, bleeding around the joints and bruising occur more frequently, and spontaneous internal bleeding can also occur. There is also a small risk of bleeding inside the skull, which is known as intracranial haemorrhage, although this usually only occurs if there has been some kind of head injury.

There are two types of haemophilia, Haemophilia A and Haemophilia B, which are caused by mutations with different clotting factors. Haemophilia A is the more common of the two. There is also a rarer form of the condition called acquired haemophilia, which can develop in both men and women as they age. This is thought to be linked to a malfunction of the immune system.

There is no cure for haemophilia, but with appropriate treatment people living with the condition can usually have a good quality of life. Treatment involves injecting clotting factors in order to prevent or treat prolonged bleeding. Without treatment, severe haemophilia can be fatal.

Aplastic Anaemia (AA)

Not enough new blood cells (mainly red blood cells) are produced and the cells that are formed are not healthy and do not function properly.  AA is not a type of cancer.

Myeloproliferative Neoplasms

These are a group of blood disorders (there are many types) that are related to leukaemia, but are not cancerous.

Myelodysplastic Syndrome (MDS)

Too many blood cells are produced in the bone marrow, but is is not known why.  These new blood cells are defective and cannot perform their functions properly.  MDS is not a a type of cancer.