Interesting Facts About Leukemia
- Leukemia (leukos – white, aima – blood) is a cancer of blood cells or bone marrow.
- Bone marrow- The spongy soft tissue which lies in the center of the bones is the bone marrow. There are two types of bone marrow, yellow and red bone marrow
- Yellow bone marrow mostly is made of fat.
- Red bone marrow comprises of the stem cells which produces three types of blood cells in the body.
- Erythrocytes also known as Red Blood Cells (RBC) – The function of the Red Blood Cells is the oxygen transportation to the cells of the body.
- Leukocytes also termed as White Blood Cells (WBC) – White Blood cells act as body defense mechanism. The principle function of these White Blood Cells is to fight infections.
- Thrombocytes with the other name Platelets – These are responsible for blood clotting.
- Lymphoma and Leukemia are two different types of cancer.
- Lymphoma- cancer of the lymphatic system
- Leukemia- cancer of the blood
- The Leukemia is diagnosed by the Blood and Bone marrow Examination.
- Statistics from the American Cancer Society shows that approximately 62,130 cases were diagnosed with leukemia in 2017.
- Times of India reports that the cases of leukemia among Delhites increased by 30% in the last five years. Population based cancer registry shows that Delhi and Mumbai have seen an alarming rise in blood cancer cases. However, the leukemia cases in rural areas are much lower compared to urban population.
Leukemia is the 10th most common cancer worldwide- World Cancer Research Fund International
What are the Symptoms of Leukemia
Leukemia is the cancer of blood cells. This blood cancer results from the development of abnormal blood cells, usually white blood cells (WBCs), in the bone marrow.
Cancer (also termed as the Malignancy) is nothing but the uncontrolled growth of abnormal cells
The principle function of the WBCs is to fight infections and invasions by viruses, bacteria, fungi, abnormal cells and foreign substances.
This action cannot be executed by the abnormal WBCs.
These abnormal white blood cells multiply aggressively, won’t die, accumulate and occupy a considerable space in the blood.
This leads to the interference in the normal functioning and growth of healthy white blood cells, which eventually end in
- Increases vulnerability to infections
- Excessive tiredness
- Easy bruising
- Excessive internal and external bleeding
In the United States, every year 54,270 new cases of Leukemia were diagnosed – Leukemia & Lymphoma Society
Due to the unregulated proliferation and multiplication of cancerous white blood cells, the body starts to show alarming symptoms.
Leukemia can either be Chronic (slow) or Acute (rapid) on the basis of the speed of its progress. Chronic leukemia remains unnoticeable until it is diagnosed by a blood test, Acute leukemia, on the other hand, shows more observable symptoms.
Compromised Immune System
White blood cells, which are crucial in fighting infections lose their expected behaviour in leukemia and go rogue. This leads the patient exposed to frequent infections and deteriorating health due to the unexpected target of healthy body cells by cancerous White blood cells.
Poor Blood Clotting
Since leukemia leads to the massive growth of WBCs to outnumber platelets that aid in blood clotting, the patient, therefore, may bruise easily and bleed profusely as the clotting and healing process slows down.
Minor hemorrhage can also occur causing tiny red to purple spots on the body. These are called Petechiae.
In leukemia, the patient’s body starves of the healthy red blood cells, resulting in Anemia.
Consequently, the patient may experience
- Dyspnea- difficult or labored respiration
- Pallor- paleness of skin
An enlargement of the spleen (splenomegaly) or liver (hepatomegaly) invokes a feeling of fullness which is convincing enough for the patient to eat less, causing the weight to lose.
This Blood Cancer results in the major disturbances of the metabolism which also leads to weight reduction.
This symptom is quite common in patients who’s CNS (Central Nervous System) has been invaded by cancerous cells.
- Night Sweats
- Flu like symptoms
- Bone pain
What are the types of leukemia
Leukemia is responsible for 1/3rd of all cancer deaths in children under 15- American Non-profit Cancer Research Foundation
Leukemias are divided into four types
The first two forms of Leukemias are classified based on how quickly the disease progresses
Acute leukemia leads to the quick multiplication of cancer cells resulting in the accumulation of immature and useless cells. Its symptoms are easily recognizable and require an aggressive and fast treatment.
Chronic leukemia progresses comparatively slowly over time. It may not present with noticeable symptoms in its beginning until the cancerous cells accumulate in a considerable amount sufficient enough to disrupt normal body functions.
The remaining two forms of Leukemias are classified based on the type of white blood cell that is affected
This type of Leukemia results from the cancerous transformation of the myeloid cells.
Lymphocytic leukemia arises from the cancerous changes in the lymphoid cells.
Usually, the stem cells in bone marrow are multipotent which have the capacity to transform into many cell types.
These multipotent stem cells replicate to produce
- Myeloid stem cells – These type of cells further differentiates into Red blood cells, Platelets and certain kinds of White Blood Cells.
- Lymphatic stem cells – These cells further differentiate into T and B lymphocytes.
Based on the above structural changes in the body due to the blood cancer cells, here is the clinical classification of Leukemia:
Acute Myelogenous Leukemia (AML)
It is the commonest among the adults and affects mostly the males. Chemotherapy is used to treat Acute Myelogenous Leukemia.
What are the risk factors of Acute Myelogenous Leukemia
- Radiation therapy and chemotherapy in the past for other cancers.
- Repeated exposure to certain chemicals like benzene
- Certain genetic disorders such as Shwachman-Diamond syndrome neurofibromatosis type 1, Klinefelter syndrome, Trisomy 8, Fanconi anemia, Wiskott-Aldrich syndrome, Down syndrome, Kostmann syndrome and Bloom syndrome.
- Progression of other blood cancers or disorders such as primary myelofibrosis, polycythemia vera, myelodysplastic syndromes (MDS) and essential thrombocythemia.
5- Year survival rate: 60-70%
Acute Lymphocytic Leukemia (ALL)
This type of leukemia is commonest among the young children. Additionally, the older adults (over 65 years of age) are more prone to develop this form of Leukemia.
5- Year survival rate: >85% for children
Chronic Myelogenous Leukemia (CML)
It is the commonest among adults. This type of leukemia responds well to the targeted cancer therapy. Gleevec (chemotherapy medication) is used along with the other drugs used to treat this form of Leukemia.
5- Year survival rate: 65.1%
90% (with targeted cancer therapy)
Chronic Lymphocytic Leukemia (CLL)
It is a common type of leukemia among adults over 55 years and is quite rare in children. Mostly the males (60% of the total cases) are affected by this disease.
CLL is believed to be incurable. The aggressive version of CLL is known as B-cell prolymphocytic leukemia.
5- Year survival rate: 82%
Clinical staging of chronic lymphocytic leukemia
|Rai Staging System|
|0||Lymphocytosis (> 5.0K/μL)|
|I||Lymphocytosis + lymphadenopathy|
|II||Lymphocytosis + hepato/splenomegaly +/- LAD|
|III||Lymphocytosis + anemia (Hgb < 11 g/dL) +/- LAD or HSM|
|IV||Lymphocytosis + thrombocytopenia (Plt < 100K/μL) +/- LAD or HSM|
|Binet Staging System|
|Rai Staging System|
|A||< 3 involved lymphoid sites|
|B||≥ 3 involved lymphoid sites|
|C||Anemia (Hgb < 10 g/dL) or thrombocytopenia (Plt < 100K/μL)|
“Stage 0 patients have extended survival, up to 12 years,”
“Stage III/IV at diagnosis still has a good survival, but it’s limited to about 8 years.”
The mutation status of immunoglobulin variable heavy chain (IgVH) is important in prognosis. Unmutated IgVH heralds aggressive disease. While patients with mutated IgVH have an expected survival of about 25 years and 80% may never need treatment, average patients with unmutated IgVH live about 9 years, and virtually all these patients will need treatment.
- Binet et al. (1981)
- Rai et al. (1975)
- J Adv Pract Oncol;7;314–317
Leukemia Treatment- Know the available option
Radiation, Smoking and Family history increase the risk of developing Leukemia
The Leukemia is treated by the specialist Doctors, Oncologists
The treatment varies according to the type and stage of this cancer. There are different treatment modalities for Chronic leukemias as they grow slowly and manifest late.
Here are the different treatment options of the Leukemia |Available Treatment for Leukemia ;
High energy radiation is targeted on a specific part or entire body to damage cancer cells, which impedes their growth.
Stem cell transplantation
Stem cell transplantation is the replacement of diseased/cancerous bone marrow cells with healthy marrow cells. The transplantation can be two types
- Autologous transplantation – transplantation where the patient is their own healthy marrow stem cell donor
- Allologous transplantation – transplantation where the healthy marrow stem cells received from a donor
The leukemia cells are killed by using a single medication or a combination of different medications.
These treatments assist the immune system in identifying the cancer cells and attacking them.
The vulnerabilities in cancer cells are exploited using the medications such as Imatinib (Gleevec), this drug targets the Chronic Myeloid Leukemia.
Monitoring For Adverse Events
Here are the potential side effects of these cancer medications
Common adverse events with Ibrutinib
- Musculoskeletal pain
If the side effects develop with the Ibrutinib, here are the Oncologist instructions
- Temporarily discontinue Ibrutinib. Resume when the side effect resolves to ≤ grade 1 and resume at the original dose.
- For second and third occurrences, take the advice of your treating oncologist.
- For a fourth occurrence, discontinue Ibrutinib.
Does Leukemia recur?
The tendency of the recurrence of leukemia depends on certain factors like
- Type of leukemia
- Patient’s response to initial treatment
- Specific molecular characteristics of the cancer cells
Acute leukemias are witnessed with fewer chances of recurrences once they are treated well. Chronic leukemias, such as Chronic Myeloid Leukemia, on the other hand, manifests with higher rates of recurrences. The treatments are targeted accordingly for the control of the disease.
Prognosis of Leukemia
All the leukemia patients who have been treated (in remission stages) needs to be checked regularly through blood tests and other examinations by their doctors. This routine examination is irrespective of the type of leukemia the patient suffered with. The intervals between these check-ups and examinations are gradually increased as the patients remain free from leukemia over the passing time.
Leukemia Survival Rate
The Survival rate of Leukemia relies on few factors such as the type of cancer and the stage it is diagnosed at. The recovery chances significantly increase with how soon it is diagnosed and treated.
- 5- Year survival rate of Acute Myelogenous Leukemia (AML): 60-70%
- 5- Year survival rate of Acute Lymphocytic Leukemia (ALL) : >85% for children
- 5- Year survival rate of Chronic Myelogenous Leukemia (CML): 65.1% and 90% (with targeted cancer therapy)
- 5- Year survival rate of Chronic Lymphocytic Leukemia (CLL): 82%
The earlier the leukemia is diagnosed and treated, the higher are the chances of quick recovery.
Certain factors like the history of blood disorders, genetic diseases related to chromosome mutations, and the older age can negatively influence the long-term outlook.
Leukemia Causes and Risk Factors of Leukemia
6 people die from Blood cancer every hour in the US – aadp.org
What exactly causes leukemia is still unknown. However, a combination of these two factors deemed to be responsible for the etiology of Leukemia
- Genetic factors
- Environmental factors
Both of the factors may give rise to the change in the cells DNA called as mutation which alters the normal functioning and the behavior of White Blood Cells.
- A chromosome translocation is one of the mutations wherein a part of a chromosome breaks off and attaches to another chromosome.
- Philadelphia chromosome is an example of such mutation. An exchange of DNA between chromosomes 9 and 22 takes place. This mostly causes Chronic Myeloid Leukemia.
Leukemia may or may not pass down the genetic line.
What Are The Risk Factors of Leukemia?
Although the reason of leukemia development is unknown, certain factors more likely increase the risk of a person to develop this cancer. However, it is not a certainity that these risk factors will definitely lead to leukemia.
Here are the known and suspected risk factors of Leukemia
Some studies have indicated that there is a higher genetic tendency to develop leukemia in a person due to the mutations in single or multiple genes inherited from parents.
There are evidences and reports suggesting that the risk of occurrence of Acute Myelogenous Leukemia, Chronic Myelogenous Leukemia and Acute Lymphocytic Leukemia tend to increase in the survivors of atomic bombs. This similar trend is observed in the people who had exposure to the radiation. However, it is only a suspected risk factor.
The ones affected with down syndrome are at a higher risk to acquire leukemia compared to the normal ones. This implies that certain chromosomal abnormalities may be responsible for the development of leukemia.
Smoking increases the risk of developing Acute Myelogenous Leukemia (AML).
Radiation or Chemotherapy
Radiation or chemotherapy taken for the treatment of cancer increases the risk of Acute Myelogenous Leukemia or Acute Lymphocytic Leukemia.
Exposure to certain chemicals like benzene might increase the risk of leukemia.
Few blood disorders like Myelodysplastic syndrome, also known as preleukemia, increases the risk of Acute Myelogenous Leukemia (AML).
Human T-cell leukemia virus type 1 (HTLV-1)
Human T-cell leukemia virus type 1 (HTLV-1) causes a rare form of leukemia.
How is Leukemia Diagnosed
The risk factors alongside the relevant symptoms may ring the alarm bells for Leukemia, but can only be confirmed with diagnostic tests such as biopsies, blood tests, and imaging and also based on the staging of leukemia.
Leukemia Diagnostic Tests
Diagnosing leukemia requires a detailed examination of blood cells.
- Complete blood count (CBC)
A Complete blood count determines the number of White blood cells, Red blood cells, and Platelets in the blood. Any Abnormal count points towards leukemia.
- Morphological study
This study is done to examine the structure of blood cells to check if there are any abnormalities in the appearance and size of the blood cells.
Bone marrow and lymph nodes tissue biopsies help in the establishment of the diagnosis of leukemia. The examination of these biopsies displays the following
- The Growth rate of the leukemia
- The type of leukemia
The biopsies of Spleen and Liver will also be done if there is a suspicion of the spread of the cancer to other organs and areas of the body.
Staging of Leukemia
Staging is required to assess the severity of the disease
- Staging Acute Myelegenous Leukemia (AML) and Acute Lymphocytic Leukemia (ALL)
Staging of AML and ALL is done by observing the type of cells involved and the appearance of cancer cells under a microscope.
- Staging Acute Lymphocytic Leukemia (ALL) and Chronic Lymphocytic Leukemia (CLL)
Staging of Acute Lymphocytic Leukemia (ALL) and Chronic Lymphocytic Leukemia (CLL) is by determining the White Bloood cells count at the time of diagnosis.
- Staging Acute Myelegenous Leukemia (AML) and Chronic Myelogenous Leukemia (CML)
Staging of Acute Myelegenous Leukemia (AML) and Chronic Myelogenous Leukemia (CML) is by detecting the immature White Bloood cells/ myeloblasts in the blood and bone marrow examination
Assessment of the growth rate of Leukemia
The growth rate of the leukemia is assessed by the following tests
- Liver function tests – The liver function tests helps to identify if the cancer cells has spread to the liver
- Flow cytometry – The flow cytometry examines the DNA of the cancer cells.
- Imaging tests – X-ray, CT scans and ultrasound to check if the leukemia has damaged other organs.
- Lumbar puncture – Lumbar puncture to collect the spinal fluid to examine if the cancer has attacked the Central Nervous System.