Myelodysplastic Syndromes (MDS)

Myelodysplastic syndromes (MDS) are a diverse group of clonal abnormalities of bone marrow hematopoietic stem cells characterized by the abnormal differentiation and maturation of blood cells. The usual clinical manifestations of MDS are anemia (decreased red blood cell levels), thrombocytopenia (decreased platelet levels), and leukopenia (decreased white blood cells levels).¹ 

The course of MDS varies among individuals and within a patient’s lifetime. Aggressive medical treatment is not always necessary, especially for patients with asymptomatic, low-risk disease, in whom it may not offer a significant survival benefit. Only symptomatic patients with severe cytopenias and a requirement for repeated blood transfusions need treatment. The primary factors determining the prognosis and overall survival of a patient are cytopenia severity, blast percentage in the peripheral blood and bone marrow, and type of chromosomal abnormalities.² 

Prognostic Parameters Affecting Life Expectancy in MDS

Prognostic parameters impacting the life expectancy of a patient with MDS can be categorized as disease-related or patient-related.³ 

Disease-Related Prognostic Factors

Disease-related factors include the patient’s type of chromosomal abnormalities and severity of blood cell count depletion.² Chromosomal abnormalities are detected by karyotyping. A normal karyotype and some abnormal karyotypes, such as loss of Y chromosome, deletion 5q, and deletion 20q, are associated with a favorable prognosis. Karyotypes associated with a poor prognosis are complex cytogenetic abnormalities (>3 abnormalities) and abnormalities in chromosome 7.³

The degree of the patient’s cytopenias reflects their hematopoietic insufficiency. Anemia, thrombocytopenia, neutropenia, and lymphocytopenia can lead to severe bleeding or infections, contributing to disease-related mortality. As well as cytopenias, increased cell counts can be also associated with a poor prognosis. It has been shown that the prognosis of patients with classic MDS may be worse in those with a high monocyte count.³

Read more about MDS complications

Patient-Related Prognostic Factors

Patient-related prognostic factors include age and comorbidities. According to the Revised International Prognostic Scoring System (IPSS-R), age at diagnosis discernibly influences the prognosis of patients with low-risk MDS but has only a limited effect on those with high-risk MDS. Severe heart failure, metastatic cancer, and other comorbidities negatively affect the prognosis across all disease categories.⁴

Read more about MDS comorbidities

MDS Survival Statistics and Life Expectancy

Many scoring systems based on various prognostic factors have been developed to estimate life expectancy in MDS. These systems assess a patient’s risk for the development of leukemia and provide an overall outlook and median survival times. Two important scoring systems are the International Prognostic Scoring System (IPSS) and the World Health Organization (WHO) Prognostic Scoring System (WPSS).⁵ 

International Prognostic Scoring System for Life Expectancy in MDS

The IPSS survival statistics are based on the IPSS-R risk groups and data from patients with MDS who were diagnosed before modern treatment, like chemotherapy, became available. This system divides patients into 5 prognostic risk groups: very low risk, low risk, intermediate risk, high risk, and very high risk. The median survival times for these groups are 8.8, 5.3, 3, 1.6, and 0.8 years, respectively.⁶

WHO Prognostic Scoring System for Life Expectancy in MDS

The WHO used 3 parameters to develop the WPSS: the WHO classification of MDS, chromosomal abnormalities, and blood transfusion requirement. This scoring system is based on data from patients with MDS who were diagnosed between 1982 and 2004.⁷ 

In addition to providing median survival times, the WPSS predicts the risk of progression to acute myeloid leukemia (AML) within 5 years. Like the IPSS-R, the WPSS divides patients into 5 risk groups: very low risk, low risk, intermediate risk, high risk, and very high risk. Median survival times for these groups in the WPSS are 11.8, 5.5, 4, and 2.2, and 0.75 years, respectively. The values for 5-year risk for progression to AML in these groups are 3%, 14%, 33%, 54%, and 84%, respectively.⁶

Read more about MDS prognosis

Genetic Factors Affecting Life Expectancy

Certain cytogenetic abnormalities are associated with a favorable prognosis. Survival is longer in patients who have MDS with isolated 5q deletion than in those who have other cytogenetic abnormalities. It has been reported that the 5-year survival rates of patients with isolated 5q deletion are 40% without treatment and approximately 54% with treatment.² 

Read more about MDS genetics

Study of Life Expectancy in MDS

An evaluation of European MDS registry data from 2008 to 2019 revealed that of 2396 patients with low-risk MDS, 900 died and that the median overall survival was 4.7 years. Median follow-up was 3.5 years. The most common cause of death was AML/MDS, which accounted for 20.1% of deaths. Infections were responsible for 17.8% of deaths, and 9.8% of patients died of cardiovascular disease.⁸

The risk for death due to cardiovascular disease was higher in patients with isolated 5q deletion who required blood transfusions. According to the 5-year relative survival rate of 59.6% and 5-year overall survival rate of 47.3%, most patients died of their underlying MDS. Patients with low-risk disease and older patients (>80 years) were more likely to die of associated causes.⁸ 

References

1. Myelodysplastic syndromes. UCSF Health. Accessed June 19, 2023.
2. Dotson JL, Lebowicz Y. Myelodysplastic syndrome. StatPearls [Internet]. Updated July 18, 2022. Accessed June 19, 2023.
3. Kasprzak A, Nachtkamp K, Gattermann N, Germing U. Assessing the prognosis of patients with myelodysplastic syndromes (MDS). Cancers (Basel). 2022;14(8):1941. doi:10.3390/cancers14081941
4. Myelodysplastic syndrome prognostic scores. American Cancer Society. Revised January 22, 2018. Accessed June 19, 2023.
5. Survival rates and outlook for myelodysplastic syndrome (MDS). Healthline. Updated January 5, 2023. Accessed June 19, 2023.
6. Survival statistics for myelodysplastic syndromes. American Cancer Society. Revised January 22, 2018. Accessed June 19, 2023.
7. What is the outlook and life expectancy of MDS?. MedicalNewsToday. Updated December 7, 2022. Accessed June 19, 2023.
8. Mądry K, Lis K, Fenaux P, et al. Cause of death and excess mortality in patients with lower-risk myelodysplastic syndromes (MDS): a report from the European MDS registry. Br J Haematol. 2023;200(4):451-461. doi:10.1111/bjh.18542

Reviewed by Hasan Avcu, MD, on 6/19/2023.

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Harshi Dhingra, MD

Harshi Dhingra is a licensed medical doctor with specialization in Pathology. She is currently employed as faculty in a medical school with a tertiary care hospital and research center in India. Dr. Dhingra has over a decade of experience in diagnostic, clinical, research, and teaching work, and has written several publications and citations in indexed peer reviewed journals. She holds medical degrees for MBBS and an MD in Pathology.