What does a 'hockey stick appearance' in Acute Myeloid Leukemia (AML) indicate and how is it treated?

From the Guidelines

The "hockey stick appearance" in Acute Myeloid Leukemia (AML) is indicative of Auer rods, which are characteristic of certain subtypes of AML, and treatment should be guided by the specific subtype and risk classification, with the most recent guidelines recommending a personalized approach based on molecular and cytogenetic features 1.

Diagnosis and Risk Classification

The presence of Auer rods, which can give a "hockey stick appearance" under microscopy, is a significant finding in the diagnosis of AML. These inclusions are particularly common in certain subtypes of AML, such as acute promyelocytic leukemia (APL). The diagnosis and subsequent treatment of AML are highly dependent on the specific subtype and the patient's risk classification, which can be favorable, intermediate, or adverse based on cytogenetic and molecular features.

Treatment Approach

Treatment for AML, especially when characterized by specific morphological features like the "hockey stick appearance" of Auer rods, should follow the latest clinical practice guidelines, which emphasize a tailored approach based on the patient's risk profile and specific genetic mutations 1. For instance, the use of gemtuzumab ozogamicin (GO) is recommended for patients with CD33-positive blasts, and the decision to proceed with allogeneic hematopoietic cell transplantation (alloHCT) versus autologous hematopoietic cell transplantation (autoHCT) or chemotherapy alone depends on the patient's eligibility and risk stratification.

Specific Considerations

• The European LeukaemiaNet (ELN) classification system is crucial for determining the risk profile of AML patients, categorizing them into favorable, intermediate, or adverse risk groups based on cytogenetic and molecular abnormalities.
• The treatment algorithm may include induction therapy with regimens such as "7+3" (7 days of cytarabine and 3 days of daunorubicin), with or without the addition of GO for CD33-positive patients, followed by consolidation therapy, which could involve chemotherapy, autoHCT, or alloHCT, depending on the patient's risk profile and response to initial treatment.
• For patients with specific subtypes like APL, the treatment approach is more standardized, involving the use of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) for induction, with chemotherapy added in high-risk cases.

Personalized Medicine Approach

The management of AML has evolved towards a more personalized approach, with treatment decisions being influenced by the patient's specific genetic and molecular profile, as well as their overall health status and preferences. This personalized approach, as outlined in the most recent clinical guidelines 1, aims to optimize outcomes by tailoring the treatment strategy to the individual patient's needs and risk profile.

From the Research

Hockey Stick Appearance in Acute Myeloid Leukemia (AML)

• The term "hockey stick appearance" is not directly mentioned in the provided studies, however, we can discuss the general treatment and prognosis of AML.
• AML is a bone marrow stem cell cancer that is often fatal despite available treatments 2.
• The diagnosis of AML is based on the presence of immature leukemia cells in the blood, and/or bone marrow or less often in extra-medullary tissues 2.
• Treatment of AML has evolved over the past few years with the advent of next-generation sequencing, targeted therapies, and improved assessment technology 2, 3.

Treatment of AML

• Induction chemotherapy based on anthracyclines and cytarabine (Ara-C) combination remains the standard of care for AML patients who are considered candidates for intensive and curative approaches 4.
• The combination of daunorubicin (DNR) for three days and cytarabine (Ara-C) as a continuous infusion for seven days, known as '3 + 7', has remained essentially unaltered over the last forty-four years and remains the standard induction regimen internationally 5.
• Novel therapies, such as CPX-351, and midostaurin in FLT3 mutated AML, have shown improved results in certain patient populations 4, 5.

Prognosis and Risk Stratification

• AML patients are stratified into different risk groups based on cytogenetic and molecular findings, which can affect treatment outcomes 2.
• Patients with adverse cytogenetic risk, secondary AML, poor-prognosis mutations, and relapse/refractory AML are considered poor-prognosis AML subsets 4.
• Genetic risk stratification should be used to determine patients who are unlikely to respond to standard intensive chemotherapy and hence, should be enrolled onto a clinical trial upfront 5.