How are Acute Myeloid Leukemia (AML) and Colorectal Cancer (CRC) diagnosed?

From the Guidelines

Acute myeloid leukemia (AML) is diagnosed through examination of peripheral blood samples and bone marrow aspirates, including morphological examination, cytochemistry, immunophenotyping, and cytogenetic analysis, as recommended by the ESMO guidelines 1. The diagnosis of AML requires a comprehensive work-up to confirm the presence of the disease and to guide treatment decisions.

• The work-up should include:
  • Morphological examination of peripheral blood and bone marrow specimens
  • Cytochemistry to identify specific cell types
  • Immunophenotyping to characterize the cells
  • Cytogenetic analysis to identify genetic abnormalities
• The WHO classification is used to classify myeloid neoplasms, including AML, based on morphology, genetics, immunophenotype, and clinical information 1.
• Colorectal cancer (CRC) diagnosis, on the other hand, typically starts with symptoms evaluation, followed by colonoscopy with biopsy of suspicious lesions, and additional tests such as CT scans, MRI, or PET scans for staging 1.
• It is essential to note that while the provided evidence focuses on AML, CRC diagnosis and screening guidelines recommend average-risk individuals to begin colonoscopy at age 45, with earlier screening for those with a family history.
• Both diseases require comprehensive pathological examination to confirm diagnosis and guide treatment decisions, with molecular and genetic profiling increasingly important for personalized therapy approaches.

From the Research

Diagnosis of AML and CRC

• The diagnosis of Acute Myeloid Leukemia (AML) can be made based on peripheral blood or bone marrow blasts 2.
• Bone marrow evaluation and peripheral blood monitoring play a crucial role in the diagnosis, management, and follow-up of AML patients 2.
• For patients with circulating blasts, multiparametric flow cytometry, cytogenetics, and molecular analysis can be performed on a peripheral blood specimen 2.
• The diagnosis of AML with myelodysplasia-related changes (AML-MRC) requires a comprehensive evaluation, including clinical history, cytogenetic analysis, mutational analysis, and/or morphologic evaluation 3.
• The European Leukemia Network has published risk classification algorithms for both intensively and non-intensively treated patients based on cytogenetic and molecular findings 4, 5.

Diagnostic Criteria for AML

• 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 4, 5.
• New biological insights have been integrated into recent classification systems, including the International Consensus Classification and the 2022 WHO system 5.
• The diagnostic criteria for AML-MRC include the patient's clinical history, cytogenetic analysis, mutational analysis, and/or morphologic evaluation 3.

Role of Bone Marrow Evaluation

• Bone marrow evaluation is currently the de facto standard for response assessment in AML patients 2.
• Bone marrow sampling is used to document hypocellularity in response to induction chemotherapy and to evaluate remission and measurable residual disease 2.
• However, the sensitivity of bone marrow testing is in some cases superior to peripheral blood evaluation for monitoring of relapse 2.

CRC Diagnosis

• There is no direct evidence provided for the diagnosis of Colorectal Cancer (CRC) in the given studies.
• The studies primarily focus on the diagnosis, risk-stratification, and management of Acute Myeloid Leukemia (AML) 2, 3, 4, 6, 5.