LONG-TERM SURVIVORS IN MYELODYSPLASTIC SYNDROMES - A REPORT ON 63 CASES AND COMPARISON WITH SHORT AND INTERMEDIATE SURVIVORS

Sixty-three of 373 patients (17%) with de novo myelodysplastic syndrom e (MDS) survived more than 5 yr (long survivors). At diagnosis, they u sually had no or only moderate cytopenias; 63% of them had marrow blas ts <5%; only 1 patient had circulating blasts; 60% had refractory anae mia (RA) or refractory anaemia with ringed sideroblasts (RARS); 19% of the 43 patients who were karyotyped had an abnormal clone, and only 2 patients had complex cytogenetic findings. Only 4 of the 63 patients progressed to another FAB type within 5 yr of diagnosis, from RA to re fractory anaemia with excess of blasts (RAEB) or chronic myelomonocyti c leukaemia (CMML). After 5 yr, 9 patients showed progression (includi ng progression to AML in 5 patients). The other patients remained stab le (43 cases) or died from cytopenias or unrelated disorders (11 cases ). Except for 3 patients who achieved prolonged complete remission wit h intensive chemotherapy, and possibly 3 patients who responded to low dose Ara C, prolonged survival seemed to result mainly from the low n atural course of the disease. Although, as expected, significant diffe rences for age, cytopenias, circulating and bone marrow blasts, and ka ryotype were seen between short (<2 yr) and long (>5 yr) very few sign ificant differences were seen between intermediate and long survivors. These 2 subgroups only differed by significantly lower age and higher haemoglobin level in long survivors. Multivariate scoring systems (Bo urnemouth, Sanz's and Lille scores) proved of relatively limited value in differentiating them. Thus, currently known prognostic factors in MDS are capable of identifying short survivors, but cannot as readily distinguish patients who will have an intermediate survival from truly long survivors.