The International Prognostic Scoring System (IPSS), originally published in 1997, is used by many doctors to help assess the severity of a patient's
myelodysplastic syndrome
A myelodysplastic syndrome (MDS) is one of a group of cancers in which blood cells in the bone marrow do not mature, and as a result, do not develop into healthy blood cells. Early on, no symptoms typically are seen. Later, symptoms may includ ...
(MDS). Based on the IPSS score, the patient's history, and the physician's own personal observations, the physician will design a treatment plan to address the MDS. A revised IPSS, IPSS-R was published in 2012. The IPSS-M, published in 2022, includes six categories based on hematologic parameters, cytogenetic abnormalities, and somatic mutations of 31 genes.
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Process
The IPSS-M uses "prognostic indicators" to develop a "score" which may be useful in understanding how the MDS may progress:
:* the proportion of
blast cells in the bone marrow
:* the type of
chromosomal changes, if any, in the
marrow cells
:* the presence of one or more low blood cell counts (
cytopenias
Cytopenia is a reduction in the number of mature blood cells. It can have many causes, and commonly occurs in people with cancer being treated with radiation therapy or chemotherapy. Types
* Anemia – a reduction of the red blood cells in the bo ...
), namely
hemoglobin
Hemoglobin (haemoglobin, Hb or Hgb) is a protein containing iron that facilitates the transportation of oxygen in red blood cells. Almost all vertebrates contain hemoglobin, with the sole exception of the fish family Channichthyidae. Hemoglobin ...
,
platelets
Platelets or thrombocytes () are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cyto ...
, or
absolute neutrophil count (ANC)
:* the presence of mutations in any of 16 main effect genes
:* the presence of mutations in any of 15 residual genes
Each indicator is rated according to its severity and the ratings are combined into a "score".
Scores are sorted into one of six risk categories:
:* very low
:* low
:* moderate-low
:* moderate-high
:* high
:* very high
IPSS-M determined that multihit
TP53
p53, also known as tumor protein p53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory transcription factor protein that is often mutated in human cancers. The p53 proteins (originally thou ...
mutations,
FLT3
Cluster of differentiation antigen 135 (CD135) also known as fms like tyrosine kinase 3 (FLT-3 with fms standing for "feline McDonough sarcoma"), receptor-type tyrosine-protein kinase FLT3, or fetal liver kinase-2 (Flk2) is a protein that in human ...
mutations, and partial tandem duplication mutations of
KMT2A
Histone-lysine ''N''-methyltransferase 2A, also known as acute lymphoblastic leukemia 1 (ALL-1), myeloid/lymphoid or mixed-lineage leukemia 1 (MLL1), or zinc finger protein HRX (HRX), is an enzyme that in humans is encoded by the ''KMT2A'' gene.
...
(MLL) were strong predictors of adverse outcomes. Some
SF3B1
Splicing factor 3B subunit 1 is a protein that in humans is encoded by the ''SF3B1'' gene.
Function
This gene encodes subunit 1 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and U2 spliceosom ...
mutations were associated with favorable outcomes, whereas certain genetic subsets of SF3B1 mutations were not.
The IPSS-M model can handle missing data and allows for the score to be applied in diagnostic settings in which not all mutations can be tested.
The IPSS-M model is useful for the risk stratification of patients with MDS to predict leukemia-free survival, overall survival, and risk of leukemic transformation. Patients with high, or very high-risk IPSS-M might benefit from allogeneic hematopoietic stem cell transplantation.
A web-based calculator is available at https://www.mds-foundation.org/mds-iwg-pm/
References
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Myeloid neoplasia