Myelodysplastic syndrome (Myelodysplasia) lastic synd romes (MDS) clinically includes several disorders, all of which are characterized by morphologically pathologic The essence of MDS is the continuous expansion of malignant clonal cells, resulting in the destruction of the immune system and pathological changes in the bone marrow microenvironment. This is a feature shared by all MDS subtypes. There is also a tendency for MDS to transform into AML. The symptoms and characteristics of different MDS subtypes are similar, but the disease progression may be completely different, so the variability of MDS disease makes it important to evaluate the patient’s prognosis. For the clinician, the decision to treat, how and when to treat relies heavily on the course of MDS disease. Clinicians not only weigh the potential toxicities versus benefits of the available treatment options, but also understand the risks of not treating MDS. For those patients with clinically asymptomatic and low-risk MDS, the best option is to withhold treatment and follow up. For patients with high-risk MDS, early application of a more toxic chemotherapy regimen to prolong the patient’s life is the right choice, such as DNA methylation inhibitors. Methods for predicting the prognosis of MDS are developing rapidly. Several such tools are described below: 1. The Interna tional Prognostic Scoring System ( IPS S) IPSS was first published in 1997 and has since been rapidly It is the most widely used MDS prognostic scoring system. It was derived from an analysis of the clinical characteristics and overall survival of 816 patients with primary MDS. SS model includes 3 disease variables-BM primitive cell ratio, cytogenetic abnormalities, and peripheral blood cytopenia. Patients were stratified by score into low-risk, intermediate-risk-I and -II, and high-risk groups, and this grouping predicted MD The IPSS is characterized by its simplicity of operation and the integration 3 variables of the system are also routinely used for diagnostic evaluation. More importantly, it has been used as a standard for evaluating the characteristics of MDS in key clinical trials, such as the global pilot studies of ralidomide, azacitidine and decitabine. In addition, the IPSS is also used in the NCCN clinical guidelines. Although shortcomings have since been suggested for the IPSS prognostic score system, this more than does not prevent the IPSS from becoming the The limitation of the IPSS is that it is only applicable at the time of first diagnosis. i The PSS prognostic system now also includes the so-called MDS-RA EB-t, a type that has been classified as acute leukemia according to the WHO staging criteria (A L). More importantly, the IPSS weights only the blood cell series, which may underestimate the prognosis of MD S patients with only severely reduced peripheral blood count but no other risk factors. This may underestimate the prognosis of MD S patients with only severely reduced peripheral blood count but no other risk factors.2 WHO-based Prognostic Scoring System (WPS) The WHO-based Prognostic Scoring Syst 2. WHO-based Prognostic Scoring System (WPSS) WPS The WHO-based Prognostic Scoring System (WPSS) is a prognostic scoring system based on WHO MDS staging. WHO’s MDS staging is determined primarily by the cell lineage of the diseased hematopoiesis and the proportion of primitive cells in the BM. WPSS agrees with IPSS on the risk of cytogenetic abnormalities. In a recent revision, the WPSS added indicators of severe anemia as risk factors. These variables divide MDS patients into 5 distinct strata. Similar to the IPSS, the WPSS is simple to apply and its variables are routinely addressed in clinical diagnosis. The NCCN guidelines also include the WPSS to guide M DS treatment. Another feature of the WPSS is that it is based on time points rather than clinical diagnosis, which makes it an important point system.3. Low-risk M isk MDS Prognostic Scoring System (Lower-R isk MDS Prognostic Scoring System. (LR-PSS) MD Anderson Cancer Center’s L R-PSS is designed for patients with IPSS score of low risk or The MD Anderson Cancer Center’s L R-PSS is designed for patients with MDS with an IPSS score of low or intermediate-risk-I.8 It was established with a study of 856 patients with low-risk MDS with short survival. patients with low-risk MDS with a short survival period were analyzed. This relatively simple model includes primitive cell proportions and cytogenetics, but places greater emphasis on age and reduced blood cell lineage, with particular emphasis on thrombocytopenia. This point system classifies patients with low- or intermediate-risk-I MDS into 3 categories. Nearly 1/3 of the patients were classified in category 3, i.e., with IPSS intermediate-risk- II patients who have a median overall survival compared to those with IPSS intermediate-risk-II. Patients with MDS in category 3 are at higher risk according to the IPSS score, which is important because clinical guidelines recommend more aggressive treatment regimens for patients with higher-risk MDS.4,9,10 Although L R-PSS is an improvement on the IPSS, the revised post-IPSS also adds the factors of severe hematocrit reduction and age, so the application of LR-PSS is limited. 4, MD Anderson Comprehensive Scoring System (MDA-PSS) ystem, MDA- CSS) MD Ande The investigators of MD Anderson have published another MDS prognostic model to address some of the shortcomings of the I The MDA-CS S is based on a study of clinical variables in 1915 patients with MDS. These patients included treatment-related MDS, CMML, and non-primary M The MD A-CSS, like the IPSS, also included cytogenetics, the primitive cell ratio and reduced blood cell lineage. However, the MDA-CSS evaluates anemia and thrombocytopenia separately, increasing the weight of severe thrombocytopenia. In addition, the MDA-CSS explicitly includes patient age, Ea stern Cooperative Oncology Group performance status and previous RBC transfusion. DA-CSS is also an IPS S was improved so that the MDA-CSS could be applied to re substratification of patients in each stratum of the IPSS. Similar to the WPSS, it does not target only initially diagnosed MDS patients as the IPSS does. MDA-CS The disadvantage of the MDA-CSS is that it is complex to perform, but of course it does not require additional parameters and experimental validation. Although the correctness of MDA-CSS has been confirmed, it has not been adopted by accepted clinical practice guidelines.5. Revised IPSS (Revis ed IPSS, IPS S-R) A revised version of the IPSS was recently released, which builds on a review of 7 A recent revision of the IPSS was released, which was based on a study of 7,012 patients with MDS in the United States and Europe. More evidence continues to demonstrate the inherent flaws of the original IPSS. Operationally, MDS patients are also evaluated at diagnosis, and patients not treated with ralidomide or demethylating drugs and not undergoing bone marrow transplantation may also be included in the IPS S-R evaluation. Although the IPSS-R also has shortcomings, it has been used to evaluate azacitidine or ralidomide clinical trials in M DS patients at risk, and the evaluation node of IPSS-R is not only at the time of diagnosis, but when necessary. The most important update to the IPSS-R is the inclusion of more chromosomal abnormalities, so the stratification is also more subdivided into 5 cytogenetic criterion groups, whereas the IPSS is 3. compared to 3 for IPSS. Although a proportion of primitive cells >2% suggests a poor prognosis, the IPSS-R for B M progenitor cell proportion has been given less weight. In addition, the IPSS-R evaluates whole blood cytopenia separately into leukopenia, erythrocytopenia, or thrombocytopenia. These variables divide MDS patients into 5 criticality groups and use age as a cut-off for each group, while the original IPS S was divided into 4. Application of the IPSS-R is available online at htt p://www.ipss- r. com operation. Compared with IPSS, IPSS- R is more specific about risk stratification, but it is also more complex and has not been used in clinical guidelines or for clinical trials. These factors have weakened the speed with which the IPSS-R has gained widespread acceptance, but it is believed that as our research on biological indicators deepens, it will further improve the overall application of these clinical Other prognostic indicators have been shown to have prognostic value for several variables that are not included in conventional scoring systems, including serum lactate dehydrogenase (LDH), physical status, and serum ferritin. Other potential prognostic indicators include BM fibrosis, b2 microglobulin, and flow cytometric analysis. The risk of death in patients with MDS stems not only from hematologic disease, but also from comorbidities. Age and physical status do not fully reflect the patient’s full picture, and examination of non-hematologic diseases may also improve our ability to predict the prognosis of MDS patients. However, comorbidity models have a different impact on patients and clinicians. In this context, molecular biological abnormalities can help determine the prognostic risk of MDS. Gene expression profiles (GEP) and SNP-As are associated with prognosis of MDS. In some MDS patients, even SNP-A abnormalities with ” normal” cytogenetics are suggestive of poor prognosis. However, both GEP and SNP-A assays are not standardized and their different assays may suggest The prognosis is different. Currently, neither of these two tests is standardized for myeloid tumors. In contrast, somatic mutations are relatively easy to detect, and more than 40 genetically recurrent mutations are present in most MDS patients to a greater or lesser extent. Mutations or epigenetic alterations in shear factor genes are expressed in more than 70% of MDS, such as TET2 and DNMT3. 2 and DNMT3. Somatic mutations in specific genes are associated with prognostic factors such as complex karyotype, increased percentage of primitive cells, and severity of allogeneic cytopenias. In addition to correlation, mutations in several genes have independent IPSS and LR-P SS in terms of prognostic value. In particular, mutations with TP53, EZH2, E TV6, RUNX1 and A SXL1 gene mutations in MDS patients had a shorter survival than IP SS has a shorter prognosis. In conclusion, IP SS is now in widespread use, and it has improved the clinical management of MDS and prompted the updating of prognostic models. Each prognostic model has its own scope of application, but so far, none of them has reached the same level of acceptance as IPSS. However, as the molecular mechanisms of MDS progress, the detection of genetic abnormalities and mutations will improve the prognostic evaluation of MDS and will eventually help in the diagnosis, staging and treatment of MDS. DS diagnosis, staging and selection of treatment options, just like the recognition of AML and MPN s process.