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Several prognostic systems have been devised to better predict the outcome of individual patients. The IPSS⁶ has been in place since 1997. The prognostic score includes the percentage of blasts and number of cytopenias and cytogenetics⁶ (Tables 26.5 and 26.6). Favourable cytogenetics includes the loss of the Y, 5q, or 20q chromosomes or the presence of a normal karyotype. Adverse cytogenetic changes were those with three or more cytogenetic abnormalities or any abnormalities involving chromosome 7. Number scores are attributed to each variable, thus dividing patients into four categories based on the sum of scores for each variable. The usefulness of the IPSS is limited by the fact that patients with secondary MDS were excluded from the analysis, and the information only pertains to patients at the time of diagnosis and cannot be used to estimate the real‐time risk for patients. Furthermore, it may underestimate the impact of cytogenetics.

Table 26.6 IPSS Survival for MDS and evolution to AML.

Source: Adapted from Greenberg et al.⁶

Risk category	Score	Median survival (years) in the absence of therapy	25% AML progression (years) in the absence of therapy
Low	0	5.7	9.4
Intermediate‐1	0.5–1.0	3.5	3.3
Intermediate‐2	1.5–2.0	1.1	1.1
High	2.5	0.4	0.2

The revised IPSS score (IPSS‐R) was published in 2012.¹⁸ This score includes a new cytogenetic risk classification that divides patients into five cytogenetic categories (Table 26.7).

Table 26.7 Cytogenetic prognostic groups in the IPSS‐R.

Source: Adapted from Hong et al.⁴⁴

Prognostic groups	Chromosomal categories	Median survival time (months)
Very good	del(11q), −Y	60.8
Good	Normal, del(5q), double aberrations including del(5q), del(12p), del(20q)	48.5
Intermediate	del(7q), +8, i(17q), +19, any other, independent clones	25.0
Poor	inv(3)/t(3q)/del(3q), −7, −7/7q, double aberrations including −7/7q−, complex karyotypes with 3 abnormalities	15.0
Very poor	Complex karyotypes with >3 abnormalities	5.7

To overcome some of the limitations of the IPSS, which excludes patients with therapy‐related myelodysplastic syndrome, proliferative chronic myelomonocytic leukaemia, and those who have received prior therapy, a group at the University of Texas M.D. Anderson Cancer Center developed a new prognostic scoring system (MDACC) that included all of these patients.⁶¹ This model identified four prognostic groups based on a prognostic score that included age, performance status, platelet count, haemoglobin, white blood cell count, bone marrow blast percentage, complex karyotype, and chromosome 7 abnormality and prior transfusions.

In an attempt to incorporate dynamic variables such as transfusion burden, the WHO prognostic scoring system (WPSS), based on WHO 2008 categories, was developed.⁶² This model takes into account WHO subgroups, karyotype, and transfusion requirement to classify patients into five risk groups with variable median survivals (12–103 months) and probability of leukaemia conversion. The advantage of the WPSS is that it is a dynamic prognostic scoring system that can be used for patients at any time during the course of their disease.

A retrospective study by Fega et al. demonstrates that there are other significant predictors of survival in older adults. Low serum albumin, Charlson score, performance status, ability to take a long walk, and interference of physical symptoms in family life are significant predictors to consider.⁶³ In the study, the multivariate model that best predicted mortality included low serum albumin, therapy‐related MDS, IPSS score, and ease taking a long walk.