Incidence and survival rates of hematological malignancies in Japanese children and adolescents (2006–2010): based on registry data from the Japanese Society of Pediatric Hematology

Early Diagnosis and Monitoring of Neurodegenerative Langerhans Cell Histiocytosis

Background

Neurodegenerative Langerhans Cell Histiocytosis (ND-LCH) is a rare, unpredictable consequence that may devastate the quality of life of patients cured from LCH. We prospectively applied a multidisciplinary diagnostic work-up to early identify and follow-up patients with ND-LCH, with the ultimate goal of better determining the appropriate time for starting therapy.

Methods

We studied 27 children and young adults with either ND-LCH verified by structural magnetic resonance imaging (MRI) (group 1) or specific risk factors for (diabetes insipidus, craniofacial bone lesions), but no evidence of, neurodegenerative MRI changes (group 2). All patients underwent clinical, neurophysiological and MRI studies.

Results

Seventeen patients had MRI alterations typical for ND-LCH. Nine showed neurological impairment but only three were symptomatic; 11 had abnormal somatosensory evoked potentials (SEPs), and five had abnormal brainstem auditory evoked potentials (BAEPs). MR spectroscopy (MRS) showed reduced cerebellar NAA/Cr ratio in nine patients. SEPs showed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for predicting ND-LCH of 70.6% (95%CI, 44.0%-89.7%), 100% (69.2%-100%), 100% (73.5%-100%), and 66.7% (38.4%-88.2%), respectively. Repeated investigations in group 1 revealed increasingly abnormal EP parameters, or neurological examination, or both, in nine of fifteen patients while MRI remained unchanged in all but one patient.

Conclusion

A targeted MRI study should be performed in all patients with risk factors for ND-LCH for early identification of demyelination. The combined use of SEPs and careful neurological evaluation may represent a valuable, low-cost, well-tolerated and easily available methodology to monitor patients from pre-symptomatic to symptomatic stages. We suggest a multidisciplinary protocol including clinical, MRS, and neurophysiological investigations to identify a population target for future therapeutic trials.

Ethnicity, race, and socioeconomic status influence incidence of Langerhans cell histiocytosis

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease, and its etiology is not well understood. Population-based studies may contribute to etiologic research by defining incidence patterns. This study was designed to evaluate the descriptive epidemiology of disseminated LCH in the United States, using data from population-based cancer registries.

PROCEDURE

We analyzed the incidence and survival of disseminated LCH in children and adolescents (0-19 years) from 18 SEER registries during 2000-2009. Age-standardized incidence rates (ASIR) per million and rate ratios (RR) were calculated by gender, race, ethnicity, age, and socioeconomic variables (crowding, rural/urban, education, and poverty) using the SEER*Stat software 8.0.1. Relative survival (RS) estimates were calculated using Ederer II method.

RESULTS

One hundred forty-five cases of disseminated LCH were recorded; ASIR was 0.70/million per year. Lower ASIR was observed for blacks (vs. whites) (RR = 0.41, 95% CI 0.18-0.81), while higher ASIR was noted for Hispanics (vs. non-Hispanics) (RR = 1.63, 95% CI 1.15-2.29). Risk of LCH was higher in crowded counties (RR = 1.84, 95% CI 1.31-2.58) and also in areas with low educational level (RR = 1.49, 95% CI 1.02-2.22). Five-year relative survival was 90.0% (95% CI 83.0-94.2). Important differences in survival were noted according to gender (male: RS = 96.0 vs. female: RS = 83.4%, P = 0.029) and age (<1 year: RS = 78.5, 1-4 years: RS = 95.6%, 5-19 years: RS = 100%, P = 0.004).

CONCLUSIONS

This population-based study shows significant variations in the incidence of disseminated LCH by race and ethnic group, as well as the influence of socioeconomic factors. These data may provide clues to causation and point toward the need for analytical epidemiologic studies.

Childhood cancer mortality in Japan, 1980-2013

Background

This study aimed to provide an updated analysis of childhood cancer mortality rates and long-term trends to 2013 to describe the current level of deaths and identify changes in recent decades.

Methods

Data on number of deaths from cancer in children aged under 15 years were derived from Vital Statistics in Japan and the World Health Organization (WHO) mortality database for comparison countries. Trends in mortality were examined by fitting a joinpoint regression model.

Results

For all cancers combined, the mortality rate during 2010–2013 was 19.9 per 1,000,000 population for boys and 17.5 for girls in Japan. Mortality from all cancers combined decreased significantly from 1980 to 2003 for boys and from 1980 to 2001 for girls. Afterwards, the rates remained stable for both sexes. Mortality from leukemia declined over the entire study period by 4.6 % per year (p <0.05) in boys and 4.3 % per year (p <0.05) in girls. For central nervous system (CNS) tumors, a slight increase in mortality was observed for both sexes, with a statistically significant annual percent change (APC) of 0.5 % (p <0.05) for boys and 0.6 % (p <0.05) for girls.

Conclusions

We provided updated information on recent trends of childhood cancer death. The establishment of a nationwide, childhood cancer registry is required in Japan. Moreover, trends in cancer mortality should be monitored continuously.

Global characteristics of childhood acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) comprises approximately 5-10% of childhood acute myeloid leukemia (AML) cases in the US. While variation in this percentage among other populations was noted previously, global patterns of childhood APL have not been thoroughly characterized. In this comprehensive review of childhood APL, we examined its geographic pattern and the potential contribution of environmental factors to observed variation. In 142 studies (spanning >60 countries) identified, variation was apparent-de novo APL represented from 2% (Switzerland) to >50% (Nicaragua) of childhood AML in different geographic regions. Because a limited number of previous studies addressed specific environmental exposures that potentially underlie childhood APL development, we gathered 28 childhood cases of therapy-related APL, which exemplified associations between prior exposures to chemotherapeutic drugs/radiation and APL diagnosis. Future population-based studies examining childhood APL patterns and the potential association with specific environmental exposures and other risk factors are needed.

Pediatric AML: From Biology to Clinical Management

Pediatric acute myeloid leukemia (AML) represents 15%-20% of all pediatric acute leukemias. Survival rates have increased over the past few decades to ~70%, due to improved supportive care, optimized risk stratification and intensified chemotherapy. In most children, AML presents as a de novo entity, but in a minority, it is a secondary malignancy. The diagnostic classification of pediatric AML includes a combination of morphology, cytochemistry, immunophenotyping and molecular genetics. Outcome is mainly dependent on the initial response to treatment and molecular and cytogenetic aberrations. Treatment consists of a combination of intensive anthracycline- and cytarabine-containing chemotherapy and stem cell transplantation in selected genetic high-risk cases or slow responders. In general, ~30% of all pediatric AML patients will suffer from relapse, whereas 5%-10% of the patients will die due to disease complications or the side-effects of the treatment. Targeted therapy may enhance anti-leukemic efficacy and minimize treatment-related morbidity and mortality, but requires detailed knowledge of the genetic abnormalities and aberrant pathways involved in leukemogenesis. These efforts towards future personalized therapy in a rare disease, such as pediatric AML, require intensive international collaboration in order to enhance the survival rates of pediatric AML, while aiming to reduce long-term toxicity.

Pediatric AML: From Biology to Clinical Management

Pediatric acute myeloid leukemia (AML) represents 15%–20% of all pediatric acute leukemias. Survival rates have increased over the past few decades to ~70%, due to improved supportive care, optimized risk stratification and intensified chemotherapy. In most children, AML presents as a de novo entity, but in a minority, it is a secondary malignancy. The diagnostic classification of pediatric AML includes a combination of morphology, cytochemistry, immunophenotyping and molecular genetics. Outcome is mainly dependent on the initial response to treatment and molecular and cytogenetic aberrations. Treatment consists of a combination of intensive anthracycline- and cytarabine-containing chemotherapy and stem cell transplantation in selected genetic high-risk cases or slow responders. In general, ~30% of all pediatric AML patients will suffer from relapse, whereas 5%–10% of the patients will die due to disease complications or the side-effects of the treatment. Targeted therapy may enhance anti-leukemic efficacy and minimize treatment-related morbidity and mortality, but requires detailed knowledge of the genetic abnormalities and aberrant pathways involved in leukemogenesis. These efforts towards future personalized therapy in a rare disease, such as pediatric AML, require intensive international collaboration in order to enhance the survival rates of pediatric AML, while aiming to reduce long-term toxicity.

Transplantation for juvenile myelomonocytic leukemia: a retrospective study of 30 children treated with a regimen of busulfan, fludarabine, and melphalan

We report the outcomes of 30 patients with juvenile myelomonocytic leukemia (JMML) who received unmanipulated hematopoietic stem cell transplantation (HSCT) with oral or intravenous busulfan, fludarabine, and melphalan between 2001 and 2011. Mutations in PTPN11 were detected in 15 patients. Six patients received human leukocyte antigen (HLA)-matched HSCT from related donors, and 24 patients received HSCT from alternative donors, including 13 HLA-mismatched donors. Primary engraftment failed in five patients, all of whom had received allografts from HLA-mismatched donors. HLA-mismatched HSCT resulted in poorer event-free survival than HLA-matched HSCT (28.8 vs. 70.6 %). Three patients died of transplantation-related causes, and eight patients experienced hematological relapse (including five patients who died due to disease progression). Eight patients received a second HSCT, and four of these patients have survived. The 5-year estimated overall survival for all patients was 72.4: 88.9 % for the patients without a mutation in PTPN11 (n = 10) and 58.3 % for the patients with a mutation in PTPN11 (n = 15) (P = 0.092). The conditioning regimen reported in the present study achieved hematological and clinical remission in >50 % of patients with JMML who received HSCT from alternative donors, and may also be effective for JMML patients with PTPN11 mutation.

Outcome of pediatric acute lymphoblastic leukemia with very late relapse: a retrospective analysis by the Tokyo Children's Cancer Study Group (TCCSG)

Relapse period is strongly associated with second relapse risk in relapsed acute lymphoblastic leukemia (ALL) in children. In this context, the treatment outcome of very late relapse should be better; however, data regarding very late relapse is limited. We retrospectively analyzed the outcomes of two consecutive Tokyo Children's Cancer Study Group (TCCSG) ALL trials (1995-2004) with a focus on late relapse, which was divided into two categories: late relapse (6-24 months from the end of therapy, n = 48) and very late relapse (>24 months from the end of therapy, n = 57). Forty-three patients (29 late relapse and 14 very late relapse) received allogeneic hematopoietic stem cell transplantation (HSCT) at second remission. The event-free survival (EFS) probabilities of late relapse and very late relapse were 54.5 ± 7.3 and 64.8 ± 6.8 % at 7 years, respectively (P = 0.36), and were not significantly different. However, the second relapse incidence of late relapse (34.7 ± 7.1 %) was higher than that of very late relapse (15.5 ± 5.1 %, P = 0.03). The second relapse risk was low for very late relapse ALL, which suggests that these patients should be treated without allogeneic HSCT.

Acute myeloid leukemia in adolescents and young adults: challenging aspects

Treating adolescents and young adults (AYAs) diagnosed with cancer is a challenge. Acute myeloid leukemia (AML) which is usually diagnosed in a previously healthy kid, requiring immediate aggressive chemotherapy, brings difficulties and conflicts associated with severe illness to extremes. The incidence of AML in adolescents aged 15-19 years approaches 8.5 per million. Only in recent years has it become evident that the prognosis of AYAs diagnosed with AML is poorer compared to younger children diagnosed with AML with similar characteristics. No specific genetic aberration or other known poor risk factor was found to explain the inferior prognosis of AYAs. In acute lymphoblastic leukemia the contribution of differences between adult and pediatric protocols to AYA outcome is established. It has been suggested that pediatric protocols should also apply to AYAs with AML; however, data supporting this are vague. Herein, existing evidence regarding special considerations in treating AYAs with AML is discussed. Mental and psychological age-specific aspects important to consider when treating AYAs with AML are overviewed. Awareness for adolescent special needs, adherence to protocols and intensive supportive care are important. Multidisciplinary adolescent-oriented staff should be involved in the therapy of any AYA with AML escorting this special patient population on the road to cure.

Recent advances in Langerhans cell histiocytosis

The purpose of this review is to provide an updated overview of the pathogenesis and treatment of Langerhans cell histiocytosis (LCH). The pathogenesis of LCH remains obscure and the optimal treatment for LCH has not been established, although incremental progress has been made. Proinflammatory cytokines and chemokines are known to play a role in LCH, which suggests that LCH is an immune disorder. However, the oncogenic BRAF mutation is also detected in more than half of LCH patients, which suggests that LCH is a neoplastic disorder. Remaining major issues in the treatment of LCH are how to rescue patients who have risk-organ involvement but do not respond to first-line therapy, the optimal treatment for the orphan disease of multifocal adult LCH, and how to reduce and treat central nervous system-related consequences, such as central diabetes insipidus and neurodegeneration. More research is needed to better understand the pathogenesis of this disease and to resolve the treatment issues.

Improved treatment results of children with B-cell non-Hodgkin lymphoma: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group B-NHL03 study

BACKGROUND

Previous Japanese studies of childhood B-cell non-Hodgkin lymphoma (B-NHL) have shown a favorable outcome, though the study size was too small to effectively assess the efficacy and safety of treatment for childhood B-NHL.

PROCEDURE

We performed a nation-wide prospective B-NHL03 study to assess the efficacy and safety of short-pulse intensive chemotherapy for children with B-NHL. They were stratified into four treatment groups according to disease stage, tumor resectability and bone marrow/CNS involvement: Group 1 with all resected stage I/II, Group 2 with non-resected stage I/II, Group 3 with stage III & CNS-negative stage IV, and Group 4 with CNS-positive stage IV & Burkitt leukemia. Treatment duration was 2 courses for Group 1, 4 courses for Group 2, and 6 courses for Groups 3 and 4, respectively. CNS irradiation was omitted in all patients.

RESULTS

The follow-up time ranged from 0.8 to 88 months, with a median of being 45 months. For 321 patients analyzed in this study, overall survival and event-free survival (EFS) at 4 years was 92.7% and 87.4%, respectively. The 4-year EFS according to treatment group were 94% for Group 1 (n = 17), 98% for Group 2 (n = 103), 84% for Group 3 (n = 111), and 78% for Group 4 (n = 90). There was no significant difference in outcome by histology. Therapy-related death occurred in three patients in remission.

CONCLUSIONS

Our nationwide large-scale study resulted in a cure rate above 90% with <1% toxic death in childhood B-NHL.

Risk factors for diabetes mellitus and impaired glucose tolerance following allogeneic hematopoietic stem cell transplantation in pediatric patients with hematological malignancies

Long-term surviving recipients of allogeneic hematopoietic stem cell transplantation (HSCT) often suffer from diabetes mellitus (DM). We sought to identify risk factors for the development of post-transplant DM and impaired glucose tolerance (IGT) in pediatric HSCT patients. Glucose tolerance statuses were evaluated in 22 patients aged 6.3-21.8 years who had received allogeneic HSCT between the ages of 0.8-13.5 years. Five patients were diagnosed as having type 2 DM, and treated with insulin or oral hypoglycemic agents. Five patients were included in the IGT group, and the remaining 12 children were in the normal glucose tolerance (NGT) group. The cumulative incidence of DM plus IGT was 11.6 % at 5 years and 69.3 % at 10 years. None of the patients were obese/overweight and none had a family history of DM. There were no significant differences in serum levels of leptin and adiponectin between the DM + IGT and the NGT groups. An average preprandial glucose levels in the DM + IGT group were significantly higher than those in the NGT group from preparative conditioning to 60 days after HSCT. In multivariate analysis, an age of ≥6 years at the time of HSCT was significantly associated with the development of DM + IGT. Additionally, careful follow-up is necessary, even for NGT patients.