Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG

INTRODUCTION

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy.

METHODS

This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes.

RESULTS

From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 10⁹/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS.

CONCLUSION

This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 10⁹/L contributed to a worse outcome.

ABBREVIATIONS

APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Better survivals in adolescent and Young adults, compared to adults with acute lymphoblastic leukemia - A multicenter prospective registry in Thai population

Adult acute lymphoblastic leukemia (ALL) is an uncommon hematologic malignancy with high relapse and mortality rate. This study aimed to describe characteristics and outcomes of Thai ALL patients, and to determine the differences between adolescent and young adult (AYA) and adult ALL. ALL patients aged > 15 years were prospectively enrolled from 2015 to 2017. AYA patients were defined as age ≤ 39 years. Out of the 188 enrolled ALL patients, 9 were excluded due to changes in diagnosis or incomplete data. From the remaining 179 patients, 103 (57.5%) were AYA and 76 (42.5%) were adult. AYA ALL patients were predominantly male, had higher T-cell phenotype, higher white blood cells and hemoglobin, with lower frequency of Philadelphia chromosome or BCR-ABL1 mutation. All patients received treatment by adult hematologist, however 40.8% of AYA ALL patients were treated with pediatric adapted protocol. The effects of stem cell transplantation (SCT) and age were determined by stratified patients as: AYA - no SCT 91 (51.1%), AYA - SCT 12 (6.7%), adult - no SCT 64 (36.0%) and adult - SCT 11 (6.2%). The 2-year overall survival were: 53.9%, 60.6%, 39.2% and 70.1%, respectively. The 2-year event-free survival were: 45.0%, 54.0%, 21.0% and 49.9%, respectively. This is a large multicenter ALL cohort study conducted in Thailand. Patients who underwent SCT showed significantly improved OS and EFS, confirming the benefit of graft-versus-leukemia effect in ALL. However, further studies with longer follow-up, expanded use of SCT, use of molecular data, and minimal residual disease status are warranted.

Amifostine and hematologic effects

Amifostine is a protective agent of normal tissue from adverse effects of radiochemotherapy. It is the prodrug that is dephosphorylated by alkaline phosphatase on plasma membrane into the active form named WR-1065. More than 90 per cent of the drug is cleared from plasma in 6 minutes and the peak tissue concentration is 10-30 minutes after intravenous administration. Amifostine has the selective property to protect normal tissue but not cancer cells by mainly scavenging free radicals induced by radiation and chemocytotoxic agents. Both preclinical and clinical studies of this drug provide the significant protection of hematopoietic progentitors from a broad range of cytotoxic agents such as cyclophosphamide, cisplatin, vinblastine, carboplatin, mitomycin-C, fotemustine, doxorubicin, daunorubicin and radiation as well. Moreover, this drug can protect other normal organs or tissues including kidney, salivary gland, liver, heart, lung and small intestine. Amifostine is quite safe, the two major side effects are vomiting and hypotension, and the minor effects are flushing, sneezing, dizziness, chills, metallic taste etc. The drug was approved by the FDA of U.S.A. for use as a cytoprotectant in cyclophosphamide and cisplatin treatment for advanced ovarian cancer and non small cell lung cancer.

HTLV-1 and Adult T-Cell Leukemia/Lymphoma: A Review

Infection with the human T-lymphotropic virus type 1 (HTLV-1) has been shown to be fundamental to the etiology of Adult T-cell Leukemia/Lymphoma (ATL). The disease is endemic in specific geographic areas but is increasingly reported from non-endemic regions. With increasing number of patients with this entity, the diversity in the clinical features has become apparent. In the past treatment strategies using combination chemotherapy have been unsatisfactory, but more recent trials using adenosine analouges, interferons, and combination of interferons and AZT have shown promise. With increased understanding of the etiology and molecular basis of the disease more effective therapies can be anticipated.

Pleomorphic large cell hemato-lymphoma (the so-called "malignant histiocytosis"): clinicopathological and immunophenotypic studies in 35 cases

Thirty-five patients diagnosed with "malignant histiocytosis" from 1984 to 1989 were studied for clinical, laboratory, histopathological features as well as survival and response to therapy, Immunocytochemistry and immunophenotypic studies were performed in 12 cases using the paraffin immunoperoxidase method. The staining included alpha-1 antichymotrypsin, muramidase, immunoglobulins and monoclonal antibodies specific for T, B lymphocytes and macrophage. From the clinical features, responsiveness to therapy and survival, the patients were divided into 2 groups: the non-responders (25 cases) and responders (10 cases) groups. Very short median survival of 1.25 months was found in the non-responders, whereas, longer median survival of 14.15 months was found in the responder group. Important different clinical and laboratory features were observed among these two groups. Unresponsiveness to treatment; rapidly progressive pancytopenia, increased hemophagocytosis, presentation of immature cells in blood with extensive infiltration of malignant cells in the bone marrow; severe jaundice and deterioration of hepatic function accompanied by early extranodal involvement were almost exclusively observed initially in the non-responder group. Satisfactory response to treatment was observed only in the responder group. Similarity of histopathology, cytology and immunophenotype was observed in these two groups. The immunophenotypic study in 12 cases showed 5 cases of B-cell lymphoma, 3 cases of T-cell (with 1 Ki-1 -positive) lymphoma; 1 case of Ki-1 positive non-T, non-B anaplastic large cell lymphoma; and 3 cases of undetermined cell lineage. From this study, so-called "malignant histiocytosis" appears to be a disorder of heterogeneity. The immunophenotypes of malignant cells indicated that their origin belonged mostly to lymphoid cell lineage. Based on their clinical feature of the early hematogenous spread along with the distinct histopathological and immunophenotypic findings, the term "pleomorphic large cell hematolymphoma" is proposed to be used instead of the old misnomer, "malignant histiocytosis" (MH).