We reviewed pre-diagnosis clinical data of 420 patients with pathologically confirmed myelodysplastic syndromes (MDS) presenting with anemia. In 232 patients with yearly pre-diagnosis blood counts (CBC) we also analyzed CBC kinetics in respects to a standardized timepoint in which all patients had similar levels of hemoglobin (Hgb). At the standardized timepoint (last documented 12 > Hgb≥11 g/dL), occurring months-years before diagnosis, median CBC values were Hgb 11.4 g/dL, neutrophils (ANC) 2.7x103 (k)/mcl, platelets (PLT) 181 k/mcl. Gradual changes in CBC could be observed years prior to this timepoint, for the most part while within normal/near-normal limits (WNL). During this time, most patients had a coexisting alternative etiology for anemia. Patients with high-risk cytogenetic/blast features had a rapid and steeper decrease in counts in the last year before developing a concerning anemia (decrease in: Hgb 0.75 g/dL vs 0.55 g/dL; PLT 29.5 vs 4.5 k/mcl; ANC 0.86 vs 0.4 k/mcl, P = 0.03). Low-risk patients had a high rate of longstanding mild anemia (31% vs 16%, P = 0.05). Rate of development of cytopenia and number of involved hematopoietic lines were prognostic. In 65% of patients, with near normal CBC at the standardized timepoint, but in whom there was a decrease in multiple hematopoietic lines over the preceding year, the 5-year overall survival (5yOS) was 53% compared to 71% in patients with isolated slowly progressing anemia (20% of patients). In 15% of patients with mild cytopenia developing after both a rapid decrease and multiple involved lines, prognosis was dismal (5yOS 34%). In conclusion, kinetics of pre-MDS CBC values correlate with disease risk and survival.
