Cancers of the Blood
Blood, as we know, carries oxygen to and from the lungs to the other parts of the body. It picks up wastes on its way back to the lungs.
Blood has different components: red blood cells, white blood cells, platelets and plasma. The red blood cells (rbc), platelets and some white blood cells (wbc) called monocytes, belong to the “myeloid” group. All other white blood cells belong to the “lymphoid” group.
The bone marrow is the place where the blood cells are mainly produced. The production of the different types of blood cells is a carefully controlled activity. When cancer affects the bone marrow, it interferes with the process that regulates cell production. White blood cells, of the Lymphoid or Myeloid variety are produced, but they do not mature into fully functioning, normal cells. These abnormal cells grow in numbers and crowd out the normal cells of the blood, and weaken the body’s defence mechanism.
Who is at risk?
Blood cancer or Leukaemia is actually a group of diseases, each of which impede with the normal functioning of blood cells and progressively weaken the system.
Depending on the type of blood cell involved, Leukaemia can be Lymphocytic or Myelogenous. Depending on the pace with which the disease progresses leukaemia is classified as either Acute or Chronic. Thus we have:
Acute Lymphocytic Leukaemia (ALL): Lymphoid cells are affected. Disease progresses quickly. This is most common among children.
Chronic Lymphocytic Leukaemia (CLL): Lymphoid cells are affected. Disease progresses over a long period. Usually affects adults, more men than women.
Acute Myelogenous Leukaemia (AML): Myeloid cells are affected. Disease progresses quickly. AML occurs in both children and adults.
Chronic Myelogenous Leukaemia (CML): Myeloid cells are affected. Disease progresses over a long period of time. More common among adults.
Specific causes have not been identified for cancers of the blood. Some factors, however, seem to have a relation.
- Exposure to radiation: People exposed to high levels of radiation are at greater risk.
- Exposure to chemicals: Those who come into contact with certain chemicals like benzene put themselves to greater risk.
- Virus attack: Human T-cell Leukaemia Virus (HTLV) is related to blood cancer incidence in some parts of the world.
- Genetic factors: Some chromosomal abnormalities are seen as related to blood cancers.