Template for Reporting Results of Biomarker Testing of Specimens From Patients With Myeloproliferative Neoplasms

Completion of the template is the responsibility of the laboratory performing the biomarker testing and/or providing the interpretation. When both testing and interpretation are performed elsewhere (eg, a reference laboratory), synoptic reporting of the results by the laboratory submitting the tissue for testing is also encouraged to ensure that all information is included in the patient's medical record and thus readily available to the treating clinical team.

Select a single response unless otherwise indicated.

Note: Use of this template is optional.*

*Reporting on the data elements in this template is not required.

___ Peripheral blood

___ Bone marrow

___ Isolated granulocytes from peripheral blood

___ Other (specify): _______________________________________________

___ No abnormalities detected

___ Abnormal karyotype detected (specify): _______________________________________________

___ BCR-ABL1

  ___ No BCR-ABL1 fusion detected

  ___ BCR-ABL1 fusion detected (specify percentage of positive cells): ______%

___ PDGFRA

  ___ No PDGFRA fusion detected

  ___ FIP1L1-PDGFRA fusion detected (specify percentage of positive cells): ______%

  ___ Other PDGFRA fusion detected (specify percentage of positive cells): ______%

___ PDGFRB

  ___ No PDGFRB fusion detected

  ___ ETV6-PDGFRB fusion detected (specify percentage of positive cells): ______%

  ___ Other PDGFRB fusion detected (specify percentage of positive cells): ______%

___ FGFR1

  ___ No FGFR1 rearrangement detected

  ___ FGFR1 rearrangement detected (specify percentage of positive cells): ______%

___ No BCR-ABL1 fusions detected

___ BCR-ABL1 fusions detected

If quantitative testing performed:

  BCR-ABL1 normalized copy number (BCR-ABL1/ reference gene): _______________________________________________

  Percent BCR-ABL1 on International Scale (e13/14a2 (p210) fusions only): _______%

___ No mutation detected

___ Mutation detected

For JAK2 p.V617F, if test is quantitative, specify quantitative value: _______________________________________________

Reported as:

  ___ Percent mutant allele burden

  ___ Percent transcript levels

  ___ Normalized copy number (V617F transcripts/ reference gene)

___ JAK2 exon 12

  ___ No JAK2 exon 12 mutation detected

  ___ JAK2 exon 12 mutation detected (specify mutation): _______________________________________________

___ MPL

  ___ No MPL mutation detected

  ___ MPL mutation detected (specify mutation): _______________________________________________

___ CALR (calreticulin)

  ___ No CALR mutation detected

  ___ CALR mutation detected (specify mutation): _______________________________________________

___ KIT

  ___ No KIT mutation detected

  ___ KIT mutation detected (specify mutation): _______________________________________________

___ Other (specify gene):

  ___ No mutation detected

  ___ Mutation detected (specify mutation): _______________________________________________

Assay sensitivity: _______________________________________________

Assay sensitivity: _______________________________________________

Assay method:

  ___ Allele-specific PCR

  ___ Sanger sequencing

  ___ Pyrosequencing

  ___ Next-generation sequencing

  ___ Other (specify): _______________________________________________

Assay sensitivity: _______________________________________________

Assay method:

  ___ Allele-specific PCR

  ___ Sanger sequencing

  ___ Pyrosequencing

  ___ Next-generation sequencing

  ___ Other (specify):

Exon(s)/codon(s) covered: _______________________________________________

Myeloproliferative neoplasms are clonal disorders characterized by the expansion of one or more myeloid lineages, leading to increased bone marrow cellularity and elevated peripheral blood myeloid cell counts. The latter may manifest as granulocytosis, erythrocytosis, thrombocytosis, or a combination of these, depending on the disease subtype. The diagnosis and classification of MPNs require synthesis of the clinical, morphologic, immunophenotypic, and molecular genetic findings. During the course of the last few years, the spectrum of genetic mutations identified in MPNs has expanded, and PCR and/or sequence-based mutation testing is now routinely incorporated into the diagnostic workup. However, the diagnosis still relies heavily on the peripheral blood and bone marrow morphologic findings and the clinical features of the disease, particularly for those patients who do not have a disease-defining genetic abnormality.

In the 2008 World Health Organization classification system, the category of MPNs includes chronic myelogenous leukemia; chronic neutrophilic leukemia; polycythemia vera; primary myelofibrosis; essential thrombocythemia; chronic eosinophilic leukemia; mastocytosis; and MPN, unclassifiable; and the clinical and pathologic findings may overlap with the category of myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, and FGFR1.¹  Classical cytogenetic karyotyping and fluorescence in situ hybridization testing are often used in the evaluation of patients to test for the presence of t(9;22)(q34;q11.2);BCR-ABL1—particularly for those who present with neutrophilic leukocytosis—and for abnormalities of PDGFRA, PDGFRB, and FGFR1 for those patients who present with eosinophilia. Otherwise, patients with MPNs may have a variety of cytogenetic abnormalities. Various trisomies, such as +8 and/or +9, are often identified. Given the degree of standardization and specialization that has occurred in BCR-ABL1 testing, and the repeated nature of the analyses, CAP has published a separate chronic myelogenous leukemia monitoring template for those patients known to have chronic myelogenous leukemia.

When the cytogenetic and/or fluorescence in situ hybridization testing results are nonspecific or negative, it may be necessary to use additional molecular genetic tests. The JAK2 p.V617F (c.1849G>T) somatic point mutation is present in almost all patients with polycythemia vera and in a large proportion (40%–50%) of patients with essential thrombocythemia or primary myelofibrosis. Both qualitative and quantitative testing methods are employed, although the utility of quantitation of the mutant JAK2 allele burden remains somewhat controversial. A small percentage of patients with polycythemia vera who lack evidence of a JAK2 p.V617F mutation may have a mutation in exon 12 of JAK2, and these are often insertions or deletions.²  Different testing methods are often used for JAK2 p.V617F and JAK2 exon 12 mutations, and it should be noted that different methods—for example, Sanger sequencing and allele-specific PCR—may have markedly different sensitivities. Mutations in the CALR (calreticulin) gene were recently identified in most patients with essential thrombocythemia or primary myelofibrosis who lack JAK2 mutations.^3,4  Less commonly, mutations in the MPL gene are present in a subset of essential thrombocythemia/primary myelofibrosis patients without JAK2 or CALR mutations.³ KIT mutation testing is helpful for the diagnosis and subclassification of mastocytosis and is important for determining the likely response to tyrosine kinase inhibitor therapy.⁵ 

Given the pace of recent findings, additional pathologically relevant mutations are likely to be identified and/or clinically validated in the near future. With this in mind, the template includes space for reporting other mutation testing, and future template updates will reflect additional molecular genetic findings that may be incorporated into the World Health Organization classification system.