Treatment outcomes of adolescent acute lymphoblastic leukemia treated on Tokyo Children’s Cancer Study Group (TCCSG) clinical trials

Outcomes of Adolescent Patients with Acute Lymphoblastic Leukemia: Long-term Follow-up of 335 Patients

BACKGROUND

Adolescents (aged 10-17 years) with acute lymphoblastic leukemia (ALL) represent a unique patient population, with a disproportionate survival disadvantage compared with younger patients. We aimed to determine the outcomes and prognostic factors of adolescent patients treated at our institution.

PATIENTS AND METHODS

Between 2005 and 2017, 335 adolescents with ALL were enrolled; clinical characteristics and treatment outcomes were analyzed and compared between adolescents and younger children (1-9 years old, n = 704).

RESULTS

Adolescents were more likely to have high-risk factors such as hyperleukocytosis, a T-cell immunophenotype, BCR-ABL1, and/or poor early treatment responses. Compared with younger children, adolescents had significantly worse 5-year event-free survival (EFS) (73.0% ± 2.5% vs. 82.6% ± 1.5%; P < .001) and overall survival (OS) (77.1% ± 2.3% vs. 87.7% ± 1.3%; P < .001). Furthermore, younger adolescents (10-14 years) tended to have better outcomes compared with those older than 15 years (5-year OS: 79.3% ± 2.5% vs. 68.4% ± 5.7%; P = .042), mainly because of the lower frequencies of toxicities. On multivariate analysis, white blood count ≥ 50 × 10⁹/L and extramedullary involvement at diagnosis were the most powerful prognostic factors for both OS and EFS.

CONCLUSION

The outcomes among adolescent patients were not as good as that of younger children. Further studies are required to define optimal treatment strategies for adolescents, particularly those aged 15 to 17 years.

Functional characterization of a germline ETV6 variant associated with inherited thrombocytopenia, acute lymphoblastic leukemia, and salivary gland carcinoma in childhood

Germline pathogenic ETV6 variants have been discovered in families with inherited thrombocytopenia and predisposition to hematological and solid malignancies. We present a patient with short stature who was initially diagnosed with chronic immune thrombocytopenia. Subsequently, the patient developed acute lymphoblastic leukemia, followed by mammary analog secretory carcinoma. Sequencing analysis identified an ETV6 c.641C > T (p.Pro214Leu) germline variant. The variant protein exhibited attenuated nuclear localization, increased protein degradation, and reduced transcription repression function. Our findings suggest that the ETV6 gene should be sequenced in patients with inherited thrombocytopenia and malignancy, and emphasize the importance of careful follow-up to identify secondary cancer in patients with pathogenic ETV6 variants.

Nationwide study of pediatric B-cell precursor acute lymphoblastic leukemia with chromosome 8q24/MYC rearrangement in Japan

BACKGROUND

Rearrangements of chromosome 8q24/MYC (8q24/MYC-r), resulting from t(8;14)(q24;q32), t(2;8)(p11;q24), or t(8;22)(q24;q11), are mainly associated with Burkitt lymphoma/leukemia (BL) and rarely observed in patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The characteristics of BCP-ALL with 8q24/MYC-r are poorly understood.

PROCEDURE

A retrospective nationwide study of data from patients with pediatric BCP-ALL with 8q24/MYC-r in Japan was conducted to clarify the clinical and biological characteristics associated with 8q24/MYC-r BCP-ALL.

RESULTS

Ten patients with BCP-ALL with 8q24/MYC-r, including three with double-hit leukemia (DHL) (two with t(8;14)(q24;q32) and t(14;18)(q32;q21) and one with t(8;14) and t(3;22)(q27;q11)), were identified. Patients with BCP-ALL with 8q24/MYC-r had higher median age and uric acid and lactate dehydrogenase levels, than those without 8q24/MYC-r. All patients were initially treated with ALL-type chemotherapy; however, four, including one with DHL, were switched to BL-type chemotherapy, based on cytogenetic findings. One patient relapsed after standard-risk ALL-type chemotherapy, and two patients with DHL did not attain complete remission with chemotherapy; all three died within 11 months. The other seven patients treated with BL-type or high-risk ALL-type chemotherapy are alive without disease.

CONCLUSIONS

The clinical and laboratory features of BL with IG-MYC rearrangement, displaying a BCP immunophenotype (Wagener et al. and Herbrueggen et al. termed it as pre-BLL), are similar to those of BCP-ALL with 8q24/MYC-r. Low-risk ALL-type chemotherapy may not be appropriate for them, and further studies are required to establish an adequate therapeutic strategy. Further studies of DHL to identify new treatment strategies are also needed.

[Multicenter clinical trial of acute lymphoblastic leukemia in elder children and adolescents]

Objective: To analyze the clinical characteristics and long-term outcomes with multicenter study for acute lymphoblastic leukemia (ALL) in children over 10 years old and adolescents. Method: Newly diagnosed ALL patients aged from 10 to 18 years old in three hospitals were included in the study from May 1(st) 2005 to April 30(th) 2015. They were received ALL-2005/2009 protocol following up to December 31(st) 2016. The clinical characteristics, outcomes and the prognostic analysis were evaluated between the two protocols. Results: Totally, 237 patients were involved in the study, 76 cases for ALL-2005 and 161 cases for ALL-2009 protocol. Complete remission (CR) after induction therapy was 94.5%. 64 (28.6%) patients relapsed with a median time of 14.5 months and 70 (29.5%) patients passed away during the following time. In long-term follow-up, the 5-year event-free survival (EFS) and 5-year overall survival (OS) of ALL patients were (63.1±3.3)% and (68.4±3.2)%. The 7-year EFS and OS were (61.0±3.5)% and (67.6±3.3)%.The 5-year EFS of intermediate risk group in ALL-2005 and ALL-2009 protocol were (73.6±6.1)% and (71.7±4.3)% with no difference (χ(2)=0.064, P=0.801). The 5-year EFS of high risk group in two protocols were (27.6±9.6)% and (33.9±9.3)%, showing no significant difference (χ(2)=0.296, P=0.586). Five years relapsed rate of two protocols were (33.8±5.7)% and (32.6±4.1)% with no difference (χ(2)=0.055, P=0.815). The mortalities were 36.8% and 29.8% separately (χ(2)=2.869, P=0.090). Univariate analysis indicated that age, male, risk, BCR/ABL translocation/t(9;22) and resistant to induction were risk prognostic factors in long-term survival (χ(2)=4.764, 4.796, 46.410, 9.560, 25.450; P=0.029, 0.029, <0.001, 0.049, <0.001). Cox multivariate analysis showed male, risk and resistant to induction were independent risk prognostic factors (RR=1.790, 2.727, 2.719; P=0.021, 0.000, 0.012). Conclusion: Protocol ALL-2009 enhanced the chemotherapy intensity in intermediate risk group with no benefit of survival. BCR-ABL fusion or t(9;22) translocation was still the risk factor of prognosis. TKI inhibitor used in these patients could improve survival. EFS rate was increased a little and death rate was decreased in ALL-2009 protocol with no significant lower relapsed rate comparing with ALL-2005 protocol.

Two Cases of Hepatoblastoma in Young Adults

Adult hepatoblastoma (AHB) is a rare liver tumor with a poor prognosis in adolescents and adults. This contrasts with hepatoblastoma in children and is not fully understood. Here we describe two adolescents with AHB who were treated in our hospital. Adolescents are likely to receive less intensive chemotherapy protocols and are treated in hospitals with less experience in pediatric oncology, resulting in poor outcome. More research is necessary for optimal treatment of AHB in adolescents. Adolescents with AHB should be referred to hospitals experienced in pediatric oncology and receive intensive chemotherapy, followed by hemihepatectomy.

Characterization of pediatric Philadelphia-negative B-cell precursor acute lymphoblastic leukemia with kinase fusions in Japan

Recent studies revealed that a substantial proportion of patients with high-risk B-cell precursor acute lymphoblastic leukemia (BCP-ALL) harbor fusions involving tyrosine kinase and cytokine receptors, such as ABL1, PDGFRB, JAK2 and CRLF2, which are targeted by tyrosine kinase inhibitors (TKIs). In the present study, transcriptome analysis or multiplex reverse transcriptase–PCR analysis of 373 BCP-ALL patients without recurrent genetic abnormalities identified 29 patients with kinase fusions. Clinically, male predominance (male/female: 22/7), older age at onset (mean age at onset: 8.8 years) and a high white blood cell count at diagnosis (mean: 94 200/μl) reflected the predominance of National Cancer Institute high-risk (NCI-HR) patients (NCI-standard risk/HR: 8/21). Genetic analysis identified three patients with ABL1 rearrangements, eight with PDGFRB rearrangements, two with JAK2 rearrangements, three with IgH-EPOR and one with NCOR1-LYN. Of the 14 patients with CRLF2 rearrangements, two harbored IgH-EPOR and PDGFRB rearrangements. IKZF1 deletion was present in 16 of the 22 patients. The 5-year event-free and overall survival rates were 48.6±9.7% and 73.5±8.6%, respectively. The outcome was not satisfactory without sophisticated minimal residual disease-based stratification. Furthermore, the efficacy of TKIs combined with conventional chemotherapy without allogeneic hematopoietic stem cell transplantation in this cohort should be determined.

Two cases with bacteremia suspected to be due to relatively rare Pseudomonas (Flavimonas) oryzihabitans

Pseudomonas oryzihabitans (formerly Flavimonas oryzihabitans) is a glucose non-fermentative, Gram-negative bacillus which is rarely isolated from human specimens. When isolated, it is on very rare occasion as a causative pathogen of catheter-related bloodstream infection in an immunocompromised patient. Herein, we describe two hematological malignancy patients suspected to have P. oryzihabitans bacteremia. We also review cases with bacteremia due to this pathogen and its microbiological characteristics.