LAUSR

We reviewed pre‐diagnosis clinical data of 420 patients with pathologically confirmed myelodysplastic syndromes (MDSs) presenting with anemia. In 232 patients with yearly pre‐diagnosis complete blood counts (CBCs), 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, absolute neutrophil count (ANC) 2.7 × 103(k)/mcl, and platelets (PLTs) 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. 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 = .03). Low‐risk patients had a high rate of longstanding mild anemia (31% vs 16%, P = .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.