Leukemia is a malignancy, or cancer, of the blood and bone marrow that primarily affects the white blood cells — the blood cells responsible for fighting off infections and other foreign organisms that enter the bloodstream. With leukemia, the bone marrow produces a higher level of immature white blood cells, weakening the immune system. The disease also affects the red blood cells and platelets and their specific cell functions, as the rapid growth and division of the abnormal blood cells can overwhelm the presence of healthy blood cells, leading to an impairment of several cell activities.
Depending on the person and the type of cells the leukemia is attacking, different signs and symptoms will appear. In the United States alone, there are about 54,000 new cases of leukemia diagnosed every year, and approximately less than 50% of those cases, or about 24,000 people, die from leukemia annually. It is believed that leukemia makes up three percent of the types of cancer in newly diagnosed patients. Thus, leukemia is a fatal disease, but there are treatment plans available, and certain types of leukemia are less fatal than others.
Factors that Affect Fatality
The fatality of leukemia, or its actual prognosis, depends on a few factors, such as the type of leukemia the person has, the age of the patient, and his or her health status. The progression of the disease will also affect prognosis. For example, if the cancer has already spread out and is affecting vital body organs, it will be more fatal. Based on previous cases, elderly people with leukemia have a higher mortality rate compared to children and young adults.
Some types of leukemia, especially for children and young adults, have a high survival rate of at least five years. With continuous advancements in medicine and cancer treatments, the chances of being treated and cured of leukemia grow each day.
As leukemia has a tendency to cause abnormal growth of white blood cells in different parts of the body, including the brain, spleen, liver, digestive system, lymph nodes, testicles, lungs, kidneys, and eyes, the body shows an array of signs and symptoms. Leukemia is divided into stages depending on the type. The factors that decide and affect the fatality of the condition are:
- Medical history of blood disorders
- Bone damage
- Chromosome abnormalities or mutations
- White blood cell or platelet count
- Enlarged spleen or liver
71% of men survive leukemia for at least one year. This falls to 54% for five years or more. This statistic is based on the diagnoses of leukemia patients during 2010–2011 in England and Wales. For women, the one-year survival rate is 60%, and this falls to 49% for five years or more. Beyond five years after diagnosis, the survival rate gradually decreases. It is predicted that 48% of men and 44% of women survive leukemia for ten years or more. This was based on patients diagnosed with leukemia from 2010–2011 in England and Wales.
Survival by Age
In younger men and women, five-year survival for leukemia is generally higher. This decreases as age increases. For patients diagnosed with leukemia in England between the years 2009–2013, the net five-year survival in men ranges from 74% in 40–49-year-olds to 29% in 80–99-year-olds. The five-year survival in women ranges from 70% in 50-year-olds to 23% in 80–99-year-olds.
Survival Rate Over Time
The survival rate is improving. Some of these are due to changes in diagnosis, classification, and registration. Interpretation of these should be undertaken carefully. In men, one-year survival has increased from 35% in 1971–1972 to 71% in 2010–2011 in England and Wales. For women, one-year survival has increased from 33% to 66%.
Since 1960, the overall survival rate has quadrupled. Major strides have been made in identifying effective treatment for leukemia. Significant progress is being made by scientists in understanding the underlying cause of the condition. Many people diagnosed with leukemia are living longer and higher quality lives. New and better ways have been discovered and implemented to prevent diagnosis and treat the condition.
Many factors that affect the rate of fatality are:
- Age of the patient at the time of diagnosis
- Whether the cancer cells have spread to the brain or spinal cord
- Whether the condition has recurred
- Patient’s response
Hence, the survival rate can improve even further.
Types of Leukemia
Based on the symptoms and facts, there are two major types of leukemia: acute and chronic. These two are further divided into more than 12 types, but there are just four among the lot that are common in children and adults between the ages of 41 and 60. The acute type is fatal, but chronic doesn’t cause immediate harm, as it grows gradually. If left untreated for long, leukemia of any type can alter the production of important cells in the lymphatic system. Without treatment, one of the most common types, acute myeloid leukemia, or ALL, can turn fatal more quickly than others. The reason behind the fatality is the fact that, being acute in nature, this form of leukemia has a tendency to spread quickly to the blood and major organs like the liver and lymph nodes.
The four main types of leukemia are classified based on the progression of the disease as well as the affected blood cells:
- The first type of leukemia is acute lymphocytic leukemia, or ALL, and it happens when the bone marrow produces an abnormally high level of lymphocytes, which is a type of white blood cell. Acute lymphocytic leukemia most commonly occurs in teens and children, primarily between the ages of two and four, but adults may also develop this type of leukemia, mostly at the age of 65 or higher. Cases have shown that children have a higher survival rate compared to adults for at least five years, which is about 85% for young ones and 50% for the adult population.
- The second type of leukemia is chronic lymphocytic leukemia, or CLL, which is a slow-progressing condition with symptoms that may not appear for a couple of years. This type of leukemia affects the lymphoid cells, which are primarily involved in the body’s immune system, and most commonly occurs in middle-aged adults, but can still be diagnosed in children and teenagers.
- The third type of leukemia is acute myeloid leukemia, or AML, also known as acute myelogenous leukemia. It is the most common acute type of leukemia among adults, although it can be diagnosed at any age. AML causes a rapid growth of myeloid cells, which are involved in different cell functions, including the immune system.
- The fourth type of leukemia is chronic myeloid leukemia, which ordinarily is only diagnosed in adults. A person with this type of leukemia may feel well for years and not show any symptoms of the disease that would necessitate treatment.
Other less common types of leukemia include:
- Hairy cell leukemia
- Acute promyelocytic leukemia, or APL, which is a subtype of AML
- Chronic myelomonocytic leukemia, or CMML
- Juvenile myelomonocytic leukemia, or JMML, which is diagnosed in children below six years of age
- Large granular lymphocytic leukemia, or LGL leukemia, which involves either an abnormally rapid or slow growth of lymphoid cells
Leukemia manifests differently based on its type and progression. The signs and symptoms of leukemia are directly due to the overwhelming amount of abnormal blood cells compared to the number of healthy cells, which hamper normal blood cell functions. With chronic leukemia, the symptoms may appear after several years, as the disease progresses slowly. With acute leukemia, immediate medical attention is needed, as the symptoms appear rapidly and are far worse.
The prognosis of leukemia is largely based on a five-year survival rate, meaning patients with this diagnosis should survive and live for five years or more after the diagnosis according to their doctor. Leukemia affects the red blood cells, lymphocytes, and platelets. The red blood cells' function is to carry oxygen across the body, the lymphocytes make the immune system strong, and the platelets are responsible for proper clotting of blood. Leukemic cancerous cells can travel through the bloodstream, engulf the bone marrow, and attach to vital organs of the body, making it an extremely dangerous disease.
Acute Myeloid Leukemia
Every year, an estimated 20,000 people in the United States are diagnosed with acute myeloid leukemia. On a yearly basis, an estimated 10,000 deaths take place because of it. Many receive chemotherapy treatment. Chemotherapy treats with medicines that rapidly kill cancer cells. Roughly 70%–80% of people younger than 60 after induction of chemotherapy will go into remission. In this condition, symptoms of the disease are not experienced and blood cell counts are also normal in range. People older than 60 don’t respond to the treatment and have a higher rate of fatality during it. Some people may go into remission, but they remain in that state. For patients with acute myeloid leukemia, the five-year overall survival rate is 20%, which means an estimated two hundred out of a thousand still live five years even after diagnosis. The five-year survival rate for lower-risk acute myeloid leukemia is 65%.
Factors that affect fatality of patients with acute myeloid leukemia are:
- Age: This can be a major factor in determining the response to treatment. For people under the age of 60 diagnosed with acute myeloid leukemia, the survival rate is more promising. The possible reason could be that, since the body is not in good health, it can make it difficult for their bodies to handle the strong medications of chemotherapy.
- Type of acute myeloid leukemia: Several types exist depending on the type of leukemia cell present in the bone marrow and blood. Some have a better survival outlook.
- Response to treatment: Some people show better response to treatment than others. Usually, a person who has received chemotherapy treatment and whose cancer hasn’t come back are considered curable. However, the treatment outcome is not favorable if it comes back or if the person doesn’t respond to the treatment at all.
Prognosis is also based on factors such as the outcome and analysis of blood tests, imaging studies, bone marrow biopsies, and cerebrospinal fluid examinations. Some people may show a poor prognosis, but end up living for many more years than what was predicted by the doctor.
Chronic Lymphocytic Leukemia
CLL’s survival rate is higher than many other cancers; its five-year survival rate is 83%. However, in people over the age of 75, this survival rate drops to less than 70%. The survival and fatality of chronic lymphocytic leukemia depends on a myriad of factors. This disease is more common in men, especially those over the age of 60, and some people have a higher risk of developing it. Race, gender, family history, and other blood disorders also increase the risk of developing chronic lymphocytic leukemia.
Factors that influence these include the stage of the disease, response to treatment, and certain cellular and genetic markers. Great promise has been show with a combination chemotherapy called FCR in patients who were previously treated, were in good health, and have certain favorable cellular markers. This treatment can increase survival and possibly induce a cure. However, this treatment is not suitable for people above age 65, since their kidney function is poor.
Acute Lymphoblastic Leukemia
In 2016, an estimated 6,590 people were diagnosed with this disease in the United States. It led to the death of about 1,430 people. The survival rate depends on the age of the person when diagnosed. The five-year survival rate is 85%. From 1975 to 1977, for all ages, the five-year survival rate was 41%. For adults and children, the five-year survival rate is 69%. However, the rate is improving and continues to do so over time.
Factors that affect fatality include:
- Age: According to the National Cancer Institute, people diagnosed with acute lymphocytic leukemia who are 35 years old or less have a better chance of survival. Children over age ten have a higher risk, and older adults have a poorer prognosis.
- Subtype of acute lymphocytic leukemia: Generally, those with cell subtypes pre-B, common or early pre-B, have better chances of survival than those with mature B-cell leukemia.
Chromosomal abnormalities: Different changes can occur in chromosomes due to the cancer that causes acute lymphocytic leukemia. It causes chromosomal abnormalities, and these are associated with a poorer prognosis. These abnormalities include:
- Ph1-positibe t (9; 22) abnormities
- BCR/ABL-rearranged leukemia
- t (4; 11)
- Deletion of chromosome 7
- Trisomy 8
- Response to therapy: People who show a quick response to the treatment therapy have a better survival outlook. Outlook is not good if the treatment takes longer to reach remission. Prognosis can be affected if it takes longer than four weeks to reach remission.
- Spread to nearby organs: Survival outlook is poorer if acute lymphocytic leukemia spreads to the nearby organs, including the cerebrospinal fluid.
- White blood cell count at the time of prognosis: Usually, the prognosis is poorer if the white blood cell count is higher during the diagnosis.
There are several different treatments for leukemia. Typically, it is treated through medications and chemotherapy. It is the infection that makes the immune system weak and ultimately kills the person.