sAML Subtype Testing: What to Know

There are several different types of acute myeloid leukemia (AML), including secondary AML (sAML).1 If you’ve been recently diagnosed, a hematologist-oncologist who specializes in the treatment of blood cancers may utilize a patient’s medical history to perform subtype testing, in order to help determine the specific type of sAML and inform treatment decisions.

Here’s what to know about subtype testing:
  • Samples: The same samples of blood, bone marrow and/or spinal fluid that were collected to confirm your AML diagnosis are most often used to help determine the subtype.2

  • Immunophenotyping: Immunophenotyping classifies cells by antigens on cell surfaces, which are toxins or other foreign substances that cause immune responses in the body.3 Because leukemia cells can have different antigens, this information helps determine an AML classification or subtype.2

    There are two types of immunophenotype testing: flow cytometry or immunocytochemistry. Collectively, these processes treat cells from your samples with antibodies, which are proteins that stick only to certain proteins on cells.2 Your doctor will determine which process is best for you.

  • Chromosome Tests: Unlike immunophenotyping, which looks at what’s on the cell, chromosome tests look at what’s inside the cell to help determine AML subtypes. Your genetic information is stored within your cells, which normally contain 23 pairs of chromosomes that vary widely in size and shape.4 For those with AML, cells sometimes have chromosomal changes that can help to identify certain types of the disease.2

    The three main types of chromosome tests that your doctor may perform are cytogenetics, fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR).2 All of these tests closely examine cells to look for abnormalities that may help identify the AML subtype. Cytogenetic testing uses a microscope to look at cells for chromosomal abnormalities, while FISH testing uses special fluorescent dyes that only attach to specific genes or parts of particular chromosomes, allowing for the detection of changes too small to be seen with cytogenetic testing. PCR testing is very sensitive and is best used to find gene and chromosomal changes not visible with a microscope. Your doctor will determine which test is best for you.2

It is important to remember that along with knowledge of specific genetic changes, the findings from immunophenotype and chromosome testing may help identify the best treatment choice for your subtype of sAML.

In recent years, researchers and physicians have made strides in understanding the genomic landscape for sAML, including breakthroughs in managing this type of cancer. Be sure to talk to your doctor about subtype testing and how it could play a role in your treatment.


For both of these processes, samples of cells are treated with antibodies, which are proteins that stick only to certain other proteins on cells. With immunocytochemistry, cells are then observed under a microscope; with flow cytometry, a special machine is used.