[Analysis of 4 prognostic scoring systems in 197 myelodysplastic syndrome patients]

To evaluate the prognostic significance of four scoring systems applied with predictive trends to myelodysplastic syndromes (MDS).

This study is comprised of 197 patients with MDS diagnosed in accordance with the FAB criteria and followed-up in our Department between Jan '75 and Dec '89. The following MDS subtypes were found: refractory anaemia (RA), 58 cases; sideroblastic refractory anaemia (SRA), 42 cases; refractory anaemia with excess of blasts (RAEB), 46 cases; RAEB in transformation (RAEB-T), 39 cases; and chronic myelomonocytic leukaemia (CMML), 12 cases. The following scoring systems were applied: Mufti's 1985, Varela's 1985, Sanz's 1989 and our own of 1991. The statistical analysis was performed according to Kaplan-Meier actuarial system and the log-Rank test of actuarial survival.

(1) Three groups (A, B and C) can be defined by the Bournemouth system, with median survivals of 57.6, 17 and 7.6 months, respectively. The majority of cases (118) were included in group B. Group A has not reached 25% of actuarial survival probability, whereas groups B and C did at 32 and 10 months, respectively. With regard to the morphologic subtypes, RA and SRA were included in groups A and B, and RAEB, RAEB-T and CMML pertained mostly of group C. Sixty cases (90.9%) evolving into acute leukaemia (AL) corresponded to those last groups. (2) The three groups defined by Varela's system (0-1, 2-5 and 6 or more) have median survival of 85.6, 24 and 14 months, respectively. Like in the former system, group 0-1 has not reached 25% actuarial probability, this appearing at 70 and 20 months, respectively, in groups 2-5 and greater than 6. The distribution of the cytological varieties, RA and SRA amongst the groups is heterogeneous although there are more common within the cases included in groups 0-1. All the cases evolving into AL were included in the groups 2-5 and greater than 6. (3) The 3 groups of the system proposed by Sanz (0-1, 2-3 and 4-5) had median survival of, respectively, 58, 15 and 14 months. Like in the preceding cases, group 0-1 has not reached the 25% actuarial probability, while this figure appears at 28 months for group 2-3 and at 20 months for group 4-5. RA and SRA varieties are included chiefly in group 0-1, while RAEB and RAEB-T appear mostly in groups 2-3 and 4-5. The distribution of the cases and evolving into AL in heterogeneous according to this system, although they predominate in groups 2-3 and 4-5. (4) The prognostic groups are defined by the system proposed by us (namely 0-2, 3-5, 5 greater than or equal to 6) with median survivals of 89.3, 17 and greater than 11 months, respectively. Striking difference was seen when studying the cumulated survivals observed, on each of the three percentages considered, between the groups. The different cytological varieties distributed reasonably with higher incidence of RA and SRA in group I and RAEB, RAEB-T and CMML in group III. This system offers statistical significance when comparing RA with SRA, RAEB with RAEB-T and, obviously. RA+SRA with RAEB+RAEB-T+CMML. The evolution into AL showed also statistical significance with respect to the three groups.

1. Three prognostic groups regarding the patient's survival could be established in our series with all the scoring systems analyzed, except that of Sanz. 2. Low risk (RA and SRA) and high risk (RAEB, RAEB-T and CMML) cytological varieties can be identified with all the scoring systems; that of Sanz is also capable of discriminating RA from SRA. 3. Some prediction on the possibility of evolution into AL can be attained of with each system. 4. The scoring system proposed by us shows higher discriminating capability on the cytologic varieties as well as higher predictive value on the possibility of evolution into AL. Nevertheless, it must be evaluated in other series in order to reach general acceptance.