Outcome and Prognostic Factors in Pediatric Precursor T-Cell Acute Lymphoblastic Leukemia: A Single-Center Experience

Interplay between IL6 and CRIM1 in thiopurine intolerance due to hematological toxicity in leukemic patients with wild-type NUDT15 and TPMT

NUDT15 and TPMT variants are strong genetic determinants of thiopurine-induced hematological toxicity. Despite the impact of homozygous CRIM1 on thiopurine toxicity, several patients with wild-type NUDT15, TPMT, and CRIM1 experience thiopurine toxicity, therapeutic failure, and relapse of acute lymphoblastic leukemia (ALL). Novel pharmacogenetic interactions associated with thiopurine intolerance from hematological toxicities were investigated using whole-exome sequencing for last-cycle 6-mercaptopurine dose intensity percentages (DIP) tolerated by pediatric ALL patients (N = 320). IL6 rs13306435 carriers (N = 19) exhibited significantly lower DIP (48.0 ± 27.3%) than non-carriers (N = 209, 69.9 ± 29.0%; p = 0.0016 and 0.0028 by t test and multiple linear regression, respectively). Among 19 carriers, 7 with both heterozygous IL6 rs13306435 and CRIM1 rs3821169 showed significantly decreased DIP (24.7 ± 8.9%) than those with IL6 (N = 12, 61.6 ± 25.1%) or CRIM1 (N = 94, 68.1 ± 28.4%) variants. IL6 and CRIM1 variants showed marked inter-ethnic variability. Four-gene-interplay models revealed the best odds ratio (8.06) and potential population impact [relative risk (5.73), population attributable fraction (58%), number needed to treat (3.67), and number needed to genotype (12.50)]. Interplay between IL6 rs13306435 and CRIM1 rs3821169 was suggested as an independent and/or additive genetic determinant of thiopurine intolerance beyond NUDT15 and TPMT in pediatric ALL.

Long-term treatment outcomes of children and adolescents with lymphoblastic lymphoma treated with various regimens: a single-center analysis

Background

Lymphoblastic lymphoma (LBL) is the second most common subtype of pediatric non-Hodgkin lymphoma. Modified treatments derived from the LSA2-L2 regimen resulted in encouraging survival, but toxicities and long-term sequelae have been problematic. At present, the acute lymphoblastic leukemia (ALL)-type protocol has demonstrated efficacy in LBL. We analyzed the outcomes of children and adolescents with LBL treated with various regimens.

Methods

From 1991‒2018, this study enrolled 63 patients diagnosed with LBL at Asan Medical Center. Medical records were retrospectively analyzed.

Results

Among 63 patients, most patients (38.1%) presented with stage IV at diagnosis, and two had central nervous system (CNS) involvement. At a median follow-up of 160 months, the 5-year event free survival (EFS), overall survival (OS), and relapse free survival (RFS) were 68.8%, 79.3%, and 71.3%, respectively. Among 61 patients who received chemotherapy, 27 patients (44.3%) received the NY protocol, and 14 (23.0%) received the ALL-type protocol. There was no significant difference in 5-yr OS (85.2%/78.6%), EFS (73.5%/78.6%), and RFS (73.5%/78.6%) between the NY and ALL protocol groups, regardless of immunophenotype. Thirteen patients (21.3%) received prophylactic cranial radiotherapy with no difference in the incidence of CNS relapse based on irradiation.

Conclusion

This study showed no difference in outcome between the NY and ALL-type protocols, regardless of stage or immunophenotype. In addition to improving the effectiveness of treatment, it is necessary to continuously appraise the appropriate chemotherapy regimen, considering toxicities and long-term prognosis, for pediatric LBL.