B-cell prolymphocytic leukemia: a survey of 35 patients emphasizing heterogeneity, prognostic factors and evidence for a group with an indolent course

We report a retrospective survey of 35 patients (18 males and 17 females) w ith B-Prolymphocytic leukemia (B-PLL) followed for a median of 63 months. T welve patients fulfilled Galton's original clinical and hematological crite ria, presented with prominent splenomegaly and hyperleukocytosis and showed rapid progression soon after diagnosis. Twelve cases with gradually increa sing spleen size and prolymphocyte count had an indolent course. Seven of t his group are alive 68 to 164 months after diagnosis, whereas five died fro m causes unrelated to PLL. Eleven patients who never developed impressive l eukocytosis had a Variable prognosis. In the group of 17 patients treated w ith chlorambucil and prednisone (CP) or cyclophosphamide, vincristine, pred nisone (COP) 8 achieved a partial remission (PR) with a median response of 32 months. In the group of six cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) treated patients one achieved a complete remission and tw o PR (median response was maintained for 30 months). Three patients treated with 2CdA achieved good PR Six patients remained untreated. Median surviva l was 65 months and the probability of overall survival for 3, 5, and 10 ye ars was 63%, 56% and 35%, respectively. Anemia < 11 g/dl and lymphocytosis > 100 x 10(9)/l were predictors of shorter survival in this group of patien ts. Age over 70, gender, B-symptoms at presentation, spleen size, thrombocy topenia, low IgG and complement levels, presence of paraproteinemia and the pattern of bone marrow infiltrate were not significant. Our findings show that all B-PLL may not have such a poor prognosis as described in earlier r eports. The existence of prior symptoms evolving gradually after years to o bvious PLL and cases with mild prolymphocytosis could possibly lead to unde rdiagnosis of the entity. Identification and follow-up of such cases may su ggest a different natural history, variable prognostic features and differe nt survival curves for B-PLL patients. In the light of the above, we sugges t that the therapeutic approach for B-PLL should always relate to the sever ity of the disease.