Why is leukemia called “white” blood disease?

We all know that human blood is red. Does leukemia mean that the blood has turned "white"? The blood of leukemia does turn "white", but it is not a color that can be seen by the naked eye. Instead, the blood has abnormal proliferation of white blood cells, so it is called leukemia. These abnormally increased white blood cells are usually not fully developed, so they are called bud cells or leukemia cells. The picture below shows a leukemia bud cell observed under a microscope.

Where do these abnormal bud cells come from?

Leukemia, also known as blood cancer, usually occurs in the bone marrow because the blood cells in the blood originate from the bone marrow and differentiate from the hematopoietic stem cells in the bone marrow. As we can see from the blood cell differentiation diagram below, leukemia occurs when bone marrow stem cells differentiate into bone marrow bud cells and then differentiate into various types of white blood cells. Therefore, a large number of abnormal bone marrow bud cells accumulate in the patient's bone marrow and then spread to the patient's blood, generating disease signals.

What are the symptoms of leukemia?

Leukemia patients have symptoms caused by the destruction of bone marrow hematopoietic function due to the accumulation of abnormal cells in the bone marrow. Since white blood cells can penetrate into tissues, patients may also experience symptoms caused by white blood cells infiltrating tissues. Symptoms caused by the destruction of bone marrow hematopoietic function generally include anemia, persistent fever, susceptibility to infection, and punctate bleeding in the body. These symptoms are caused by the destruction of bone marrow hematopoietic function, which leads to a lack of platelets and red blood cells, decreased immunity, and susceptibility to infection. Symptoms caused by white blood cells infiltrating tissues include swollen lymph nodes, bone pain or joint pain, swollen gums, bleeding gums, hepatosplenomegaly, pericardial effusion, etc. Of course, these symptoms are clinical symptoms that may occur in patients after being diagnosed with leukemia, and do not mean that the appearance of these symptoms is a precursor to leukemia. Once you notice that your body is abnormal, you must do a clinical examination and let the doctor make a judgment, instead of making your own judgment based on the text description of the relevant disease, scaring yourself, and maybe causing some oolong incidents.

What are the causative factors of leukemia?

Unfortunately, the exact cause of leukemia is still unknown. Environmental and genetic causes are currently considered to be the main causes of the disease. Environmental causes are caused by exposure to pathogenic factors in the environment that may cause DNA mutations in bone marrow stem cells, leading to leukemia. These pathogenic factors generally include radiation (such as radiation, chemotherapy, etc.), carcinogens (such as smoking, chemical benzene, etc.). Genetic causes are that the patient's family may have a history of leukemia, Down syndrome, etc.

Are the same types of leukemia diagnosed in adults and children?

Leukemia is a general term for a class of diseases with many types. It can be divided into lymphocytic and myeloid according to the type of abnormal white blood cells in the blood, and can be divided into acute and chronic according to the course of the disease. The specific classification is shown in the table below. Among them, the most common clinically diagnosed in adults are AML and CML, and the more common one in children is ALL.

How is leukemia treated?

Although leukemia is called "blood cancer", it is not a terminal illness. With the right treatment, the clinical cure rate of leukemia can be as high as 70%.

Treatments for leukemia include chemotherapy, radiotherapy, targeted therapy, and bone marrow transplantation. Chemotherapy is the use of drugs to kill leukemia cells or slow down the growth and division of leukemia cells; radiotherapy is the use of X-rays or gamma rays to reduce or kill leukemia cells; targeted therapy is the use of biological drugs to specifically attack leukemia cells and inhibit their growth; bone marrow transplantation is to first use anti-cancer drugs to completely kill the leukemia cells in the patient's body, and then inject the donated healthy bone marrow into the patient's body, so that normal and healthy bone marrow cells begin to differentiate into normal blood cells in the body. The cure rate of leukemia is related to many factors such as the patient's diagnosis type, age, and personal condition. The cure rate of chemotherapy for acute lymphoblastic leukemia (ALL) is 60-70%, and the 5-year survival rate of adolescent and pediatric patients under the age of 20 can reach 89%, while the 5-year survival rate of adult patients aged 20 and above is about 35%.

After acute myeloid leukemia (AML) patients receive treatment, the 5-year survival rate of adolescent and pediatric patients under the age of 20 can reach 67%, while the 5-year survival rate of adult patients aged 20 and above is about 24%. Bone marrow transplantation can improve the cure rate of AML patients. Chronic lymphocytic leukemia (CLL) is common in Western countries, and chronic myeloid leukemia (CML) is common in Asian countries. Compared with acute leukemia, chronic leukemia progresses slowly. Without bone marrow transplantation, chronic leukemia patients can still survive 3-5 more years.

Is leukemia hereditary?

Theoretically, leukemia is generally not inherited, and most clinically confirmed cases occur in patients who have no family history of leukemia. Of course, there are also some cases that show that a confirmed close relative in the family may suffer from the same type of leukemia. However, since the cause of leukemia has not yet been identified, it is impossible to conclude that leukemia will be passed on to future generations after diagnosis. Similarly, if a close relative is diagnosed with the same type of leukemia, the possibility of being diagnosed due to a similar living environment cannot be ruled out.

How to take care of leukemia patients around you?

Generally, leukemia patients who receive chemotherapy are prone to oral problems, such as oral mucosal ulcers, oral, gastrointestinal, and skin bleeding due to decreased platelets. Therefore, caregivers need to pay attention to using saline or analgesic mouthwash to help patients rinse their mouths. At the same time, since the body immunity of leukemia patients decreases after treatment, caregivers need to pay special attention to the hygiene of the environment around the patients, try to avoid patients from entering public places, and remind patients to wear masks when going out. Finally, caregivers should always pay attention to whether patients take medications on time and have regular check-ups.

References:

[1] Ai Huisheng, Luo Rongcheng, Yue Xiaofeng. Modern Leukemia[M]. Beijing: People's Military Medical Publishing House, 1997:41-58.

[2] Ma Yingchun, Dong Xiaojing, Tang Juying, et al. Correlation between social support and quality of life of leukemia patients[J]. Chinese Journal of Modern Nursing, 2009, 04, 313-315.

[3] Bowtie. [Leukemia] Learn about different types of blood cancer, early symptoms and cure rates! [EB/OL]. [2020-12-15]. https://www.bowtie.com.hk/blog/zh/白血病-血癌/.

[4] Hong Kong Cancer Fund. Treatment of acute leukemia [EB/OL]. [2017-04]. https://www.cancer-fund.org/wp-content/uploads/2017/04/Leukaemia-Pdf-2015C.pdf