Outcome of treatment in adults with Philadelphia chromosome-positive and/or BCR–ABL-positive acute lymphoblastic leukemia—retrospective analysis of Polish Adult Leukemia Group (PALG)

Patients with Philadelphia chromosome-positive (Ph+) and/or BCR–ABL+ acute lymphoblastic leukemia (ALL) have extremely poor prognoses. Most of these patients have additional, heterogenous karyotype abnormalities, the majority of which have uncertain clinical significance. In this study we analyzed the clinical characteristics, karyotype abnormalities, and outcome of 77 patients with Ph+ and/or BCR–ABL+ ALL registered in Poland in 1997–2004. In 31/55 patients with known karyotype, the sole t(9;22)(q34;q11) abnormality had been diagnosed; in one patient, variant translocation t(4;9;22)(q21q31.1;q34;q11), and additional abnormalities in 23 (42%) patients, had been diagnosed. The characteristics of the patients with Ph chromosome and additional abnormalities were not significantly different when compared with the entire analyzed group. Out of 77 patients, 54 (70%) achieved first complete remission (CR1) after one or more induction cycles. The overall survival (OS) probability of 2 years was 63, 43, and 17% for patients treated with allogeneic stem cell transplantation (alloSCT), autologous SCT, and chemotherapy, respectively (log rank p=0.002). Median OS from the time of alloSCT was significantly longer for patients transplanted in CR1 compared with alloSCT in CR >1 (p=0.032). There were no significant differences in CR rate, disease-free survival (DFS), and OS for patients with t(9;22) and additional abnormalities compared with the whole group. Only WBC >20 G/l at diagnosis adversely influenced OS probability (log rank p=0.0017). In conclusion, our data confirm poor outcome of Ph+ and/or BCR–ABL+ ALL. Only patients who received alloSCT in CR1 had longer DFS and OS. We have shown that additional karyotype abnormalities did not influence the clinical characteristics of the patients; however, their influence on treatment results needs to be further assessed.