Types of Blood Cancer
There are four types of blood cancer depending upon the course of the disease and the origin of the affected blood cells. The former criterion classifies the types into either acute or chronic. The later criterion further divides the types as lymphoblastic or lymphocytic leukemias and myeloid or myelogenous leukemias.
Blood primarily consists of red blood cells (RBC), white blood cells (WBC) and platelets. The red blood cells provide oxygen to the entire body. The white blood cells protect our body and platelets helps in clotting of the blood in the face of injury. Irrespective of the types of the disease, any abnormality in these cell types leads to blood cancer.
Based on these above mentioned criteria, the main categories of blood cancer are as follows:
- Acute Lymphocytic or Lymphoblastic Leukemias (ALL)
- Chronic Lymphocytic or Lymphoblastic Leukemias (CLL)
- Acute Myelogenous or Myeloid Leukemias (AML)
- Chronic Myelogenous or Myeloid Leukemias (CML)
What is Acute/Chronic Criterion of Blood Cancer/Leukemia?
Based on the progression of the disease and the treatment approach adopted, blood cancer is classified as either acute or chronic. The description is as follows:
Acute Cancer: The word acute refers to quick progression of this disease. It involves production of large number of immature blood cells in the bone marrow. Production of healthy blood cells as a result get hampered. This type of cancer is common among children and requires immediate commencement of treatment. It is because the abnormal cells can enter into the blood stream and spread the disease to fresh locations of the body making it incurable after a point.
Chronic Cancer: In the chronic form of the disease, there are large number of relatively mature but abnormal white blood cells produced. It takes months or even years for these abnormal cells to be produced at rate much higher than the normal blood cells. Treatment is commenced for this cancer after carefully studying the symptoms for a while. This ensures effectiveness of the healing technique adopted. Though any age group people can develop this form of cancer, it is mostly observed in elderly people.
What is Lymphoid/Myeloid Criterion of Blood Cancer/Leukemia?
The cells which make up the blood are produced in spongy central section of the bones called bone marrow. After their production, the blood cells enter into the liquid which surround the cells of the body called the lymph. The blood, bone marrow and the lymph are intimately connected to one another. Any ailment in one component certainly affects the other.
Depending upon the location where abnormal and malignant blood cancer cells originate, this ailment is further subdivided into either lymphoid or myeloid. The description is as follows:
Lymphoid Cancer: The liquid lymph is part of the lymphatic system. This system itself is a part of the natural protection system of the body, namely, the immune system. The lymphatic system mainly comprises of cells and tissues of an organ called the lymph node. It is a circular ball shaped structure present all over the body. The produced cells of this organ called the white blood cells protect our body from internal and foreign threats.
Swelling of the lymph node is the first symptom in a person suffering from any form of cancer. When white blood cells belonging to this system are affected, the cancer is lymphoid cancer.
Myeloid Cancer: As mentioned earlier, blood cells are produced in the bone marrow. The process is technically called Haematopoiesis. All these cells of blood are produced from single cell type called the stem cell. This cell has the special quality of getting converted into any other cell type in the body based on the requirement.
Nearly 1011–1012 new blood cells are produced every day inside a healthy adult’s body to maintain normal functioning. Any inconsistency in this production limit in the bone marrow leads to myeloid cancer. Mostly the red blood cells and the platelets get affected in this form of cancer.
Types of Blood Cancer:
What is Acute Lymphocytic or Lymphoblastic Leukemias (ALL)?
The normal white blood cells are meant to protect our body. But when cancer turns them malignant and these cells are produced in very high rates, threat develops for the existence of normal cells. They are quickly outnumbered and disease spreads to fresh locations of the body from the lymph node, causing death of the patient.
It mostly affects young children between 2-5 years and elderly people above the age of 65 years. 85 percent children and 50 percent adults survive this cancer through treatment options like radiation and chemotherapy.
Sub-types of ALL:
- Precursor B acute lymphoblastic leukemia
- Acute biphenotypic leukemia
- Burkitt’s leukemia
- Precursor T acute lymphoblastic leukemia
What is Chronic Lymphocytic or Lymphoblastic Leukemias (CLL)?
Here, for reasons yet to be known, there is a slow rise in the production of the B cells. These cells primarily belong to the immune system and produce substances in the blood which protect us from disease causing organisms.
The cancer affects adults above the age of 55 years. Two-thirds of them are men. It is unfortunately incurable and the treatment options ensure five-year survival rate up to 75 percent. It is rare among young people and children are almost never affected by it.
Sub-type of CLL:
It has only one more aggressive sub-type, namely the B-cell prolymphocytic leukemia.
What is Acute Myelogenous or Myeloid Leukemias (AML)?
Abnormal white blood cells abnormally grow in the bone marrow disrupting the production of normal blood cells. It is considered to a relatively rare disease. It is common in men than women. Children are hardly affected by it. The chemotherapy treatment ensures five-year survival rate up to 40 percent. It accounts for 1.2 percent of cancer related deaths in the United States. Cause of the disease is yet to be known.
Sub-types of AML:
- Acute promyelocytic leukemia
- Acute megakaryoblastic leukemia
- Acute myeloblastic leukemia
What is Chronic Myelogenous or Myeloid Leukemias (CML)?
Young abnormal white blood cells in the bone marrow are produced at an uncontrollable rate here before they enter into the blood stream. This cancer mainly affects adults and children are rarely affected by it. The five-year survival rate is 90 percent with anti-cancer drugs like imatinib.
Sub-type of CML:
There is only one subtype for CML namely the chronic monocytic leukemia.
Some Rare Types of Blood Cancer:
Waldenstrom’s Macroglobulinemia: The liquid portion of the blood is called serum which contains all the blood cells types. In this rare form of blood cancer, the serum becomes thick. There is also an excess production of a protein called IgM in the blood leading to heart failure. Men above the age of 65 years are more at risk of developing this condition.
Hairy Cell Leukemia: It is makes up just two percent of all blood cancer types. It is incurable and 80 percent of the affected people are men. It is not reported yet in the young children. It is easily treatable if the symptoms are diagnosed early. The ten-years survival rate is as high as 96-100 percent.
T-cell-prolymphocytic Leukemia: Adults above the age of 30 years are primarily affected by it. Owing to its very aggressive nature it quickly affects organs like bone marrow, lymph nodes, liver, spleen, and skin.
Large Granular Lymphocytic Leukemia: It is a non-aggressive form of cancer. The auto-immune disorder rheumatoid arthritis is also diagnosed along with the symptoms of this rare blood cancer type.
Adult T-cell Leukemia: It is believed to be caused by a virus namely the Human T cell leukemia/lymphotropic virus type 1 (HTLV-1). The T-cells of the immune system get affected in this form of blood cancer. African-Americans living in the south-east are mostly found to be affected by this cancer, though it is rare in the entire United States.
What is Cancer?
Cancer refers to a class of diseases affecting the healthy cells with more than 100 known types. Based on the properties of the affected cells, there are two types of cancer. They are benign and malignant types.
The benign cells are limited to certain confinements in the body, do not invade or spread to new locations. On the contrary, malignant cancer cells are characterized by their nature of uncontrolled growth, intruding and destroying nearby cells and spreading to fresh locations of the body.
What are the Causes of Cancer?
Cells are the building blocks of life. They carry out all the functions in the body by following certain chemical instructions called genes. The cells have certain basic properties. One such fundamental property is cell replication, where a cell creates a copy of its own by a process called cell division.
Here, a parent cell passes on its genetic instructions to two new copies of it called the daughter cells. After cell division, the parent cell dies as a part of a programmed process technically called apoptosis.
Cancer is caused when changes in the genetic material takes place (technically called as mutation) while they are transferred from parent to the daughter cells during cell division. These changes or errors are unavoidable and happen inevitably.
The errors which are few in number grow exponentially as the daughter cells in the initial stage undergoing mutation turn parent cells themselves and pass on the erroneous genetic instructions to a new bunch of cells.
In this way, cancer is a gradual process and a progressive disease. The minute errors accumulate over the time and there arrives a moment when a cell has completely erroneous set of instructions, thus behaving in a manner contrary to a normal healthy cell. In this way, a cancer cell is formed. Thus a cascade of error cells is the main cause of cancer.
Mutation can cause four types of errors leading to cancer. They are:
- Every cell has an inherent error-correcting system. When this system gets affected, errors self-amplify per cell division.
- Cells have a signalling system to communicate with each other. When mutation disrupts this system, erroneous signals are transferred between nearby cells.
- Cells grow at a particular rate. If mutation changes this pattern, then abnormal cell growth in one region can disrupt normal function of cells in remote regions too.
- Cells die their programmed death normally as per the apoptosis process. If mutation affects this process, a cancer cell can turn immortal and can become a constant and uncontrollable source of disrupting normal healthy cells forever.
Irrespective of its type, the cancer ailment can be cured if the symptoms are diagnosed early. Once the disease spreads to fresh locations (technically called as metastasis), it can only be treated to delay the unavoidable death.