Germ line genetic NBN variation and predisposition to B-cell acute lymphoblastic leukemia in children.

ABSTRACT: Biallelic mutation in the DNA-damage repair gene NBN is the genetic cause of Nijmegen breakage syndrome, which is associated with predisposition to lymphoid malignancies. Heterozygous carriers of germ line NBN variants may also be at risk for leukemia development, although this is much less characterized. By sequencing 4325 pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL), we systematically examined the frequency of germ line NBN variants and identified 25 unique, putatively damaging NBN coding variants in 50 patients. Compared with the frequency of NBN variants in gnomAD noncancer controls (189 unique, putatively damaging NBN coding variants in 472 of 118 479 individuals), we found significant overrepresentation in pediatric B-ALL (P = .004; odds ratio, 1.8). Most B-ALL-risk variants were missense and cluster within the NBN N-terminal domains. Using 2 functional assays, we verified 14 of 25 variants with severe loss-of-function phenotypes and thus classified these as nonfunctional or partially functional. Finally, we found that germ line NBN variant carriers, all of whom were identified as heterozygous genotypes, showed similar survival outcomes relative to those with wild type status. Taken together, our findings provide novel insights into the genetic predisposition to B-ALL, and the impact of NBN variants on protein function and suggest that heterozygous NBN variant carriers may safely receive B-ALL therapy. These trials were registered at www.clinicaltrials.gov as #NCT01225874, NCT00075725, NCT00103285, NCI-T93-0101D, and NCT00137111.

Indirect Effects of COVID on Oncology Patients.

The interaction of coronavirus disease-2019 (COVID-19) and chemotherapy may result in worse outcomes. However, there may be more indirect effects of COVID. We report 3 cases in which treatment was delayed because of COVID-related inability or reluctance to travel. Oncology programs should consider such indirect effects when devising treatments.

Hematopoietic Stem Cell Transplantation Activity in Pediatric Cancer between 2008 and 2014 in the United States: A Center for International Blood and Marrow Transplant Research Report.

This Center for International Blood and Marrow Transplant Research report describes the use of hematopoietic stem cell transplantation (HSCT) in pediatric patients with cancer, 4408 undergoing allogeneic (allo) and3076 undergoing autologous (auto) HSCT in the United States between 2008 and 2014. In both settings, there was a greater proportion of boys (n = 4327; 57%), children < 10 years of age (n = 4412; 59%), whites (n = 5787; 77%), and children with a performance score ≥ 90% at HSCT (n = 6187; 83%). Leukemia was the most common indication for an allo-transplant (n = 4170; 94%), and among these, acute lymphoblastic leukemia in second complete remission (n = 829; 20%) and acute myeloid leukemia in first complete remission (n = 800; 19%) werethe most common. The most frequently used donor relation, stem cell sources, and HLA match were unrelated donor (n = 2933; 67%), bone marrow (n = 2378; 54%), and matched at 8/8 HLA antigens (n = 1098; 37%) respectively. Most allo-transplants used myeloablative conditioning (n = 4070; 92%) and calcineurin inhibitors and methotrexate (n = 2245; 51%) for acute graft-versus-host disease prophylaxis. Neuroblastoma was the most common primary neoplasm for an auto-transplant (n = 1338; 44%). Tandem auto-transplants for neuroblastoma declined after 2012 (40% in 2011, 25% in 2012, and 8% in 2014), whereas tandem auto-transplants increased for brain tumors (57% in 2008 and 77% in 2014). Allo-transplants from relatives other than HLA-identical siblings doubled between 2008 and 2014 (3% in 2008 and 6% in 2014). These trends will be monitored in future reports of transplant practices in the United States.

Does FLT3 mutation impact survival after hematopoietic stem cell transplantation for acute myeloid leukemia? A Center for International Blood and Marrow Transplant Research (CIBMTR) analysis.

BACKGROUND: Patients with FMS like tyrosine kinase 3 (FLT3)-mutated acute myeloid leukemia (AML) have a poor prognosis and are referred for early allogeneic hematopoietic stem cell transplantation (HCT). METHODS: Data from the Center for International Blood and Marrow Transplant Research (CIBMTR) were used to evaluate 511 adult patients with de novo AML who underwent HCT during 2008 through 2011 to determine whether FLT3 mutations had an impact on HCT outcomes. RESULTS: In total, 158 patients (31%) had FLT3 mutations. Univariate and multivariate analyses revealed an increased risk of relapse at 3 years in the FLT3 mutated group compared with the wild-type (WT) group (38% [95% confidence interval (CI), 30%-45%] vs 28% [95% CI, 24%-33%]; P = .04; relative risk, 1.60 [95% CI, 1.15-2.22]; P = .0048). However, FLT3 mutation status was not significantly associated with nonrelapse mortality, leukemia-free survival, or overall survival. Although more patients in the FLT3 mutated group died from relapsed primary disease compared with those in the WT group (60% vs 46%), the 3-year overall survival rate was comparable for the 2 groups (mutated group: 49%; 95% CI, 40%-57%; WT group: 55%, 95% CI, 50%-60%; P = .20). CONCLUSIONS: The current data indicate that FLT3 mutation status did not adversely impact overall survival after HCT, and about 50% of patients with this mutation who underwent HCT were long-term survivors. Cancer 2016;122:3005-3014. © 2016 American Cancer Society.

Successful treatment of recurrent CNS disease post-bone marrow transplant in children with familial hemophagocytic lymphohistiocytosis.

BACKGROUND: Central nervous system (CNS) involvement is a major cause of morbidity and mortality in patients with hemophagocytic lymphohistiocytosis (HLH). Current standard of care for CNS disease utilizes high-dose systemic dexamethasone plus intrathecal methotrexate and hydrocortisone prior to transplantation. However, the morbidity and mortality remains high and there are no clear guidelines posttransplantation for screening and treatment of CNS disease. PROCEDURE: We report a single-center retrospective case series of five patients with familial HLH (FHLH) who had CNS involvement post-bone marrow transplantation (BMT). All patients were monitored with monthly lumbar punctures (LPs) prior to developing neurologic symptoms. Treatment utilized systemic dexamethasone for CNS disease control. RESULTS: Five patients were monitored with monthly or bimonthly surveillance LPs and treated with systemic dexamethasone to control CNS relapse post-BMT. All patients are alive, a median of 34 months posttransplant (range 14-66 months). Four patients have mild neurological deficits, including mild speech delay (3) and one patient who exhibited brainstem herniation on day 0, due to CNS HLH, has made a substantial recovery of function with residual deficits of focal weakness on the right side. One patient has no deficits. CONCLUSION: Our data support vigilant screening posttransplant for occult CNS disease prior to the development of symptoms and the use of systemic dexamethasone to reverse disease progression. Future prospective trials are needed to evaluate this treatment strategy.

Outcome of Children with Standard-Risk T-Lineage Acute Lymphoblastic Leukemia--Comparison among Different Treatment Strategies.

BACKGROUND: Children with T-lineage acute lymphoblastic leukemia ALL (T-ALL) historically have had inferior outcomes compared with the children with precursor-B ALL (B-ALL). After 1995, the Children's Cancer Group (CCG) treated patients with B- and T-ALL according to the National Cancer Institute (NCI) risk criteria, basing risk stratification on age and white blood cell (WBC) count regardless of immunophenotype. The Pediatric Oncology Group (POG) treated all the patients with T-ALL on separate, generally more intensive protocols than those used to treat the patients with B-ALL. PROCEDURE: We compared the outcomes of children with T-ALL and NCI standard-risk (SR) criteria treated on CCG and POG trials between 1996 and 2005. CCG SR-ALL 1952 and 1991 enrolled 80 and 86 patients with T-ALL, respectively, utilizing a reduced intensity Berlin-Frankfurt-Münster backbone. Treatment was intensified for slow early responders and only patients with overt central nervous system leukemia received cranial irradiation. Eighty-four patients with T-ALL and SR features were enrolled on POG 9404 comprising more intensive therapy with all patients receiving cranial irradiation. RESULTS: The 7-year event-free survival (EFS) for patients with SR T-ALL on CCG 1952, CCG 1991, and POG 9404 were 74.1 ± 5.8%, 81.8 ± 5.3%, and 84.2 ± 4.3%, respectively (P = 0.18). Overall 7-year survivals were 86.1 ± 4.6%, 88.3 ± 4.4%, 89.1 ± 3.6%, respectively (P = 0.84). CONCLUSIONS: Comparable high rates of EFS and long-term survival were achieved with all three regimens, with the CCG regimens utilizing a less intensive chemotherapy backbone without prophylactic cranial irradiation for patients with SR T-ALL.