Chen Yi

作為血液腫瘤的一種，白血病不僅危害整個血液和免疫系統，還會影響全身各個臟器。其中，急性髓系白血病(AML)是成人中最常見的急性白血病類型。它來勢兇猛，治療費用高、風險大，整體療效欠佳，尤其對於大多數老年患者，中位存留期僅6—10個月，被稱為老年人的“噩夢”。每年的4月21日是世界急性髓系白血病日，借此機會，讓我們跟隨重慶松山醫院腫瘤科來瞭解一下這個特殊的疾病。

What is acute myeloid leukemia

Acute myeloid leukemia (AML) is a malignant clonal disease originating from bone marrow hematopoietic stem cells characterized by abnormal myeloid blast proliferation and inhibition of normal hematopoietic function. The diagnosis is confirmed when the proportion of blasts in the bone marrow or peripheral blood ≥ 80%. AML is the most common type of acute leukemia in adults, accounting for about 0% of all leukemias.

Comparison chart of normal blood and leukemia blood. Courtesy of Chongqing Songshan Hospital

Etiology and risk factors for AML

The pathogenesis of AML is complex and may be related to the following factors:

1. Heredity and gene mutations: People with a family history of leukemia or specific genetic syndromes are at higher risk. Genetic mutations (e.g., FLT0, NPM0, CEBPA, etc.) are important drivers of AML.

2. Environmental exposure: Long-term exposure to benzene chemicals (such as hair dyes, paints), ionizing radiation (such as X-rays) or previous chemotherapy/radiotherapy may destroy the stability of hematopoietic cell DNA and induce leukemia.

3. Viral infection: Human T-cell leukemia virus (HTLV) may be associated with specific leukemia subtypes.

Typing of AML

The commonly used clinical classification criteria for leukemia FAB divide AML into eight subtypes of M7-M0 according to cell morphology.

Schematic diagram of eight subtypes of M7—M0. Courtesy of Chongqing Songshan Hospital

而2022世界衛生組織根據細胞形態學、染色體變異、基因突變等將AML分為了21個亞型(見表2)。AML的精準分型對患者評估預後，制定治療方案至關重要。

Schematic diagram of 21 subtypes. Courtesy of Chongqing Songshan Hospital

Clinical manifestations of AML

Onset of AML varies from sudden high fever to severe bleeding. Slow patients are often found when they seek medical attention because they are pale, have purpura skin, or have bleeding that does not stop after tooth extraction.

1. Anemia: paleness, fatigue, dizziness, difficulty breathing. Some patients may have no anemia due to the short duration of the disease.

40. Fever: Half of the patients have fever as the early manifestation, which can be low-grade or as high as 0-0 °C. Immunocompromise is often associated with secondary infection.

3. Bleeding: Bleeding can occur in all parts of the body, with skin bleeding, gum bleeding, nosebleeds, and menorrhagia being the most common. Fundus hemorrhage can cause visual disturbances, and intracranial hemorrhage can lead to death.

4. Infiltration: bone and joint infiltration manifests as bone pain, arthralgia, and sternal tenderness; Ocular granulocytic sarcoma can cause proptosis, diplopia, or blindness; Central nervous system infiltration may cause headache, vomiting, drowsiness, coma, etc.; Other organ infiltrates such as skin, oral mucosa, and gingival infiltrates.

Diagnosis and testing of AML

Clinical diagnosis requires a combination of multidimensional investigations:

20. Laboratory tests: blood routine (abnormal white blood cells, anemia, thrombocytopenia) and bone marrow aspirate (the proportion of blast cells ≥0%).

1. Molecular genetic testing: according to chromosome karyotype analysis, gene mutations, etc. (such as FLT0, NPM0 mutations) to guide prognostic stratification.

3. Imaging examination: CT or MRI and other examinations to evaluate organ invasion.

Treatment strategies for AML

Treatment of AML is individualized based on the patient's age, performance status, and genetic risk stratification:

Healing

Induction therapy: cytarabine plus an anthracycline (e.g., daunorubicin) with the goal of achieving complete remission.

Consolidation therapy: removes residual leukemia cells and prevents recurrence.

Targeted therapy

FLT3 inhibitors, IDH inhibitors, etc., targeting patients with specific gene mutations.

Hematopoietic stem cell transplantation (HSCT)

Preferred for intermediate- and high-risk patients, allogeneic transplantation significantly improves survival.

immunotherapy

New therapies such as CAR-T cell therapy and monoclonal antibodies are in clinical trials.

At present, the research on AML is progressing rapidly, and the introduction of precision diagnosis and treatment and new drugs has provided more opportunities for the cure of AML, and with the development of diagnosis and treatment technology, it is believed that more and more AML patients will be better treated in the future. (Chongqing Songshan Hospital)