The incidence of leukemia patients in Korea is on a steady rise. Despite an overall decline in the number of children in the country attributed to a decrease in birth rates, there has been no corresponding decrease in the number of children diagnosed with leukemia. Notably, the incidence of childhood leukemia is increasing. Moreover, the number of adult leukemia patients is expected to surge by over 50 percent within the next decade, experts say. The underlying question remains: What factors contribute to the increasing prevalence of leukemia patients in Korea?

In a YouTube channel, “I am a doctor,” Yoon Jae-ho, a professor of hematology at Seoul St. Mary's Hospital  expressed his belief that leukemia is likely the result of a combination of acquired environmental factors acting upon individuals with a specific congenitally vulnerable genome. 

He assumed that acute leukemia, in particular, may necessitate the presence of at least two genomic mutations for its development.

Leukemia, a form of blood cancer, manifests when regular blood cells within the body's hematopoietic system in the bone marrow undergo a transformation into cancerous cells and proliferate due to a "specific reason." It is posited that the onset of leukemia, particularly in the more rapidly progressing acute form, is associated with the convergence of at least two genomic mutations.

Yoon said, "A critical gene mutation is required to disrupt the normal differentiation of leukocytes, leading to the abnormal overgrowth of immature cells that become cancerous. Hence, the convergence of at least two such mutations is necessary, as seen in cases of acute leukemia."

Yoon clarified that the occurrence of leukemia does not categorize it as a genetic disease. He emphasized, "Parents of leukemia patients do not possess the same gene mutations. It is not an inherited condition." 

He suggested the possibility that individuals may inherit genes that render them vulnerable to external factors, emphasizing that while it is not strictly hereditary, there is a discernible tendency for certain cancerous diseases to exhibit familial patterns.

Leukemia stands as the most well-known among blood cancers, constituting a category of cancers originating in white blood cells. The complexity of leukemia is underscored by the diversity of white blood cell types, such as neutrophils, eosinophils, basophils, lymphocytes, and monocytes, all of which have the potential to undergo cancerous transformation. Additionally, unlike many other cancers, leukemia is uniquely classified into two main categories: acute and chronic.

He went on to say that the distinctive feature of acute leukemia involves the emergence of immature cells. These problematic cells undergo excessive growth, evolving into cancerous cells at a developmental stage before becoming neutrophils, eosinophils, or lymphocytes—the mature white blood cells originating from the bone marrow.

Chronic leukemia is characterized by the malignant proliferation of cells that have completed their differentiation, setting it apart from acute leukemia, where uncontrolled growth occurs in immature cells. Moreover, leukemia is further categorized into “myeloid” and “lymphocytic,” leading to four common types: acute myeloid leukemia, acute lymphocytic leukemia (also known as acute lymphoblastic leukemia), chronic myeloid leukemia, and chronic lymphocytic leukemia.

According to Yoon, acute myeloid leukemia is significantly more prevalent than acute lymphocytic leukemia. He notes that the vast majority of acute myeloid leukemia cases are predominantly observed in adults, making it almost exclusively an adult disease.

Acute lymphoblastic leukemia, a prevalent childhood cancer, stands out due to its notably higher incidence in infants and young children. 

Yoon said that while leukemia is believed to be triggered by genetic mutations, the mutations expressed very early in children appear to be more prevalent in lymphoid cells than in myeloid cells.

Generally, acute leukemia, whether lymphocytic or myeloid, carries a comparable survival rate globally, approximately at 40 percent over a five-year period. 

However, Yoon underscored the complexity of the disease by pointing out numerous subtypes, wherein the cure rate ranges widely from 80 percent to 20 percent. 

In the realm of acute leukemia subtypes, a pivotal prognostic factor is the presence of the Philadelphia chromosome.

Yoon said, "In B-cell lymphoblastic leukemia, where B-cell lymphocytes are expected to grow and function as immune cells, a gene mutation occurs in certain cells before they can develop into normal B-cell lymphocytes. This involves a mutation hindering differentiation and another causing overproliferation, with the Philadelphia chromosome playing a crucial role in the latter."

When patients with suspected leukemia present at the hospital, their white blood cell count typically hovers around 10,000. In contrast, leukemia patients often display a significantly elevated white blood cell count ranging from 30,000 to 40,000. Those diagnosed with Philadelphia-positive leukemia, however, tend to have an even higher white blood cell count, often exceeding 100,000.

Leukemia is a frequently diagnosed disease with no specific symptoms upon onset; however, it progressively worsens until bone marrow function ceases, leading to a variety of symptoms.

Yoon said if a persistent cold, inflammation, or similar issues linger despite treatment with antibiotics, particularly in young individuals, it may escalate or result in recurring pneumonia and similar complications.

"In acute leukemia, severe thrombocytopenia is common, marked by easy bruising, impaired hemostasis, and a profusion of purpura, especially in the lower extremities," he explained. 

He advised individuals experiencing unusual fatigue, increased bruising, or other symptoms differing in frequency or intensity from their norm to undergo a blood test measuring red blood cell, white blood cell, and platelet levels.