Characteristics, outcomes, prognostic factors and treatment of patients with T-cell prolymphocytic leukemia (T-PLL)

Abstract

Background: T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive disease. In this study, we report our experience from 119 patients with T-PLL.

Patients and methods: We reviewed the clinico-pathologic records of 119 consecutive patients with T-PLL, who presented to our institution between 1990 and 2016.

Results: One hundred and nineteen patients with T-PLL were analysed. Complex karyotype and aberrations in chromosome 14 were seen in 65% and 52% patients, respectively. Seventy-five patients (63%) were previously untreated and 43 (37%) were initially treated outside our institution. Sixty-three previously untreated patients (84%) received frontline therapies. Overall, 95 patients (80%) have died. Median overall survival (OS) from diagnosis was 19 months [95% confidence interval (CI) 16-26 months]. Using recursive partitioning (RP), we found that patients with hemoglobin < 9.3 g/dl, lactate dehydrogenase (LDH) ≥ 1668 IU/l, white blood cell ≥ 208 K/l and β2M ≥ 8 mg/l had significantly inferior OS and patients with hemoglobin < 9.3 g/dl had inferior progression-free survival (PFS). In multivariate analysis, we identified that presence of pleural effusion [hazard ratio (HR) 2.08 (95% CI 1.11-3.9); P = 0.02], high LDH (≥ 1668 IU/l) [HR 2.5 (95% CI 1.20-4.24); P < 0.001)], and low hemoglobin (< 9.3 g/dl) [HR 0.33 (95% CI 0.14-0.75); P = 0.008] were associated with shorter OS. Fifty-five previously untreated patients received treatment with an alemtuzumab-based regimen (42 monotherapy and 13 combination with pentostatin). Overall response rate, complete remission rate (CR) for single-agent alemtuzumab and alemtuzumab combined with pentostatin were 83%, 66% and 82%, 73% respectively. In patients who achieved initial CR, stem cell transplantation was not associated with longer PFS and OS.

Conclusion: Outcomes in T-PLL remain poor. Multicenter collaborative effort is required to conduct prospective studies.

Keywords: T-PLL; prolymphocytes; prolymphocytic leukemia.

Figure 1

Survival outcomes in patients with T-PLL—overall and according to the treatment status at the time of initial presentation to MDACC—frontline versus salvage treatment. (A) All patients from the time of initial diagnosis, median OS was 19 months. (B) PFS is significantly longer in patients treated in frontline setting (P = 0.0002). (C) OS is significantly longer in patients treated in frontline setting (P = 0.01). Survival outcomes according to the type of frontline therapy. (D and G) PFS and OS in patients who received therapy with alemtuzumab (single-agent alemtuzumab or in combination with pentostatin) versus other therapies (P = 0.03 for PFS and P = 0.09 for OS). (E and H) PFS and OS in patients who received alemtuzumab (single agent alemtuzumab versus alemtuzumab with pentostatin (P = 0.01 for PFS and P = 0.03 for OS). Survival outcomes according to treatment with SCT in patients who achieved complete remission after frontline therapy. (F) PFS was not significantly different in patients with/without SCT (P = 0.07). (I) OS was not significantly different in patients with/without SCT (P = 0.31). Survival outcomes in patients with T-PLL, according to the prognostic factors identified by recursive partitioning (RP) analysis. (J–L) OS was significantly shorter in patients with low hemoglobin (<9.3 g/dl), high serum LDH (≥1668 IU/l) and high β2M (≥8 mg/l) level.