Molecular and clinicopathologic characterization of pediatric histiocytoses.

The spectrum of somatic mutations in pediatric histiocytoses and their clinical implications are not fully characterized, especially for non-Langerhans cell histiocytosis (-LCH) subtypes. A cohort of 415 children with histiocytosis from the French histiocytosis registry was reviewed and analyzed for BRAFV600E . Most BRAFWT samples were analyzed by next-generation sequencing (NGS) with a custom panel of genes for histiocytosis and myeloid neoplasia. Of 415 case samples, there were 366 LCH, 1 Erdheim-Chester disease, 21 Rosai-Dorfman disease (RDD), 21 juvenile xanthogranuloma (JXG, mostly with severe presentation), and 6 malignant histiocytosis (MH). BRAFV600E was the most common mutation found in LCH (50.3%, n = 184). Among 105 non-BRAFV600E -mutated LCH case samples, NGS revealed mutations as follows: MAP2K1 (n = 44), BRAF exon 12 deletions (n = 26), and duplications (n = 8), other BRAF V600 codon mutation (n = 4), and non-MAP-kinase pathway genes (n = 5). Wild-type sequences were identified in 17.1% of samples. BRAFV600E was the only variant significantly correlated with critical presentations: organ-risk involvement and neurodegeneration. MAP-kinase pathway mutations were identified in seven RDD (mostly MAP2K1) and three JXG samples, but most samples were wild-type on NGS. Finally, two MH samples had KRAS mutations, and one had a novel BRAFG469R mutation. Rarely, we identified mutations unrelated to MAP-kinase pathway genes. In conclusion, we characterized the mutational spectrum of childhood LCH and clinical correlations of variants and subtypes. Variants responsible for JXG and RDD were not elucidated in more than half of the cases, calling for other sequencing approaches.

Fitness and metabolic response to exercise in young adult survivors of childhood lymphoma.

PURPOSE: Childhood lymphoma survivors (CLSs) are at high risk of reduced daily activity. This work studied metabolic substrate use and cardiorespiratory function in response to exercise in CLSs. METHODS: Twenty CLSs and 20 healthy adult controls matched for sex, age, and BMI took an incremental submaximal exercise test to determine fat/carbohydrate oxidation rates. Resting echocardiography and pulmonary functional tests were performed. Physical activity level, and blood metabolic and hormonal levels were measured. RESULTS: CLSs reported more physical activity than controls (6317 ± 3815 vs. 4268 ± 4354 MET-minutes/week, p = 0.013), had higher resting heart rate (83 ± 14 vs. 71 ± 13 bpm, p = 0.006), and showed altered global longitudinal strain (- 17.5 ± 2.1 vs. - 19.8 ± 1.6%, p = 0.003). We observed no difference in maximal fat oxidation between the groups, but it was reached at lower relative exercise intensities in CLSs (Fatmax 17.4 ± 6.0 vs. 20.1 ± 4.1 mL/kg, p = 0.021). At V̇O2 peak, CLSs developed lower relative exercise power (3.2 ± 0.9 vs. 4.0 ± 0.7 W/kg, p = 0.012). CONCLUSION: CLSs reported higher levels of physical activity but they attained maximal fat oxidation at lower relative oxygen uptake and applied lower relative power at V̇O2 peak. CLSs may thus have lower muscular efficiency, causing greater fatigability in response to exercise, possibly related to chemotherapy exposure during adolescence and childhood. Long-term follow-up is essential and regular physical activity needs to be sustained.

Locoregional failure after postoperative flank irradiation for nephroblastoma: Results from the French cohort of the SIOP-2001 trial.

OBJECTIVE: To describe locoregional failure (LRF) after postoperative flank radiotherapy (RT) among French patients with nephroblastoma included in the Société Internationale d'Oncologie Pédiatrique (SIOP)-2001 protocol. PATIENTS AND METHODS: In selected SIOP-2001 patients, planning with simulation computed tomography (CT) scan and posttreatment CT scan demonstrating LRF were registered and analyzed. LRF was contoured and classified as in-field, marginal or out-of-field according to dose distribution. RESULTS: Total 316 French SIOP-2001 patients were treated with postoperative RT. Three patients with nephroblastoma developed LRF after flank RT. All failures were located within the retroperitoneum. In two patients, the relapse was within the RT field and in one it was classified as marginal. CONCLUSION: LRF after postoperative flank RT for nephroblastoma was rare and exclusively situated in the retroperitoneum. These results point out this region as the most at risk of local relapse. A prospective evaluation of a target volume restricted to the retroperitoneum allowing the use of modern and highly conformal radiation techniques in order to decrease dose to normal tissues shall be encouraged.

Leukapheresis in management of hyperleukocytosis in children's leukemias.

We describe 16 leukapheresis (LK) procedures performed in 7 children with different types of leukemia and hyperleukocytosis. We also provide an analysis of previously published experiences of pediatric LK. Median age and body weight of patients were 12.3 years (range, 0.2 to 16.7 y) and 49 kg (range, 5 to 61 kg). Immediate pre-first-LK median white blood cell count was 478×10/L (108×10/L to 988×10/L). All cytoreduction were performed on Cobe Spectra cell separator. Sixty-eight percent of procedures were performed with peripheral veins. Extracorporeal line had been primed with red blood cell for 31% of LK. The median decrease in white blood cell count after each LK was 33% (0% to 69%), and overall decrease after completion of LK procedures was 62% (11% to 94%). Only minor clinical adverse events and no metabolic complication were attributable to LK. No more clinical symptom of hyperleukocytosis was observed after completion of LK procedures. Our findings are consistent with reported results in other pediatric series: LK is a well-tolerated procedure that can be safely performed with an experienced pediatric team even on the smallest children.

NK cell immunotherapy for high-risk neuroblastoma relapse after haploidentical HSCT.

Little is known on strategies to prevent or to treat relapses occurring after haploidentical stem cell transplantation (haplo-HSCT) performed for the high-risk neuroblastoma (NB). We describe a 6-year-old male with refractory NB who relapsed 22 months after haplo-HSCT. A complete remission was obtained with a combination of immuno-chemotherapy based on donor NK cells transplants, IL2 infusions and temozolomide/topotecan. This case is an incentive to explore both the immediate therapeutic effect of haplo-graft provided via haplo-NK cells and the immunogenic platform that haplo-HSCT offers for future treatment. Our post-relapse strategy shows that chemo- and bio-treatment should be viewed as complementary therapeutic options.

Childhood Leukemia Survivors and Metabolic Response to Exercise: A Pilot Controlled Study.

BACKGROUND: Leukemia is the most common cancer in pediatrics, with many late effects such as higher risk of dyslipidemia, insulin resistance, obesity, and metabolic syndrome. The objective of this work was to investigate substrate oxidation during submaximal exercise in survivors of childhood acute leukemia. METHODS: A total of 20 leukemia survivors and 20 healthy children were matched by sex, age, and Tanner stage. They all took a submaximal incremental exercise test to determine fat and carbohydrate oxidation rates. RESULTS: Cardiorespiratory fitness was significantly lower in leukemia survivors, with lower relative VO2 peaks (p < 0.001), lower heart rate values (p = 0.02), and lower exercise power (p = 0.012), whereas rest metabolism and body mass index did not differ between the two groups. During exercise, upward of heart rate relative to VO2 peak was significantly higher (p < 0.001) in childhood leukemia survivors. We found lower carbohydrate and fat oxidation rates (p = 0.07) in leukemia survivors compared with healthy children, and also a significantly lower relative maximal fat oxidation rate (p = 0.014). CONCLUSION: Despite impaired physical fitness and metabolic response to exercise, childhood leukemia survivors remained sensitive to physical activity interventions, and could readily adapt to submaximal exercise intensity.

[Access to fertility preservation for adolescents and young adults aged 15 to 24 years with cancers in Auvergne, France]. / Accès à la préservation de la fertilité des adolescents et jeunes adultes de 15 à 24 ans atteints de cancers en Auvergne, France.

INTRODUCTION: Cancers of adolescents and young adults have particular epidemiological specificities. The improvement in their survival should be accompanied by an increased consideration of the treatments' side effects, among which the potential decrease in fertility. The objective of the study was to describe the access to fertility preservation of these patients at the University Hospital of Clermont-Ferrand over a period of 3 years. METHODS: During this retrospective descriptive study, various socio-demographic and clinical data were collected. RESULTS: One hundred and fifty new cases of cancers were diagnosed in patients aged 15 to 24 years. Forty-four percent received at least one fertility consultation, 29 % for girls and 58 % for boys (P<0.001). The number of cases that did not result in fertility preservation was significantly higher for girls than boys (P=0.005). Fertility preservation was mainly achieved by cryopreservation of ovarian tissue in female adolescents, ovocytes in young women and sperm in boys. DISCUSSION: We observed sex disparities in access to fertility preservation. Despite the existence of recommendations, progress remains to be made. The establishment of clinico-biological platforms should allow a better awareness of patients and professionals, and thus promote access to fertility preservation techniques for young patients with cancer.

Dysautonomia in Childhood Cancer Survivors: A Widely Underestimated Risk.

PURPOSE: Survival rate of childhood cancers is now reaching 80% overall. However, early or late complications related to surgery, chemotherapy, and radiotherapy remain at a high rate and greatly increase the risk of late mortality. The objective of this study is to assess the autonomic nervous system (ANS) activity, measured through heart rate variability indices in childhood cancer survivors compared with healthy controls. METHODS: This prospective study included 51 long-term childhood cancer survivors diagnosed before 15 years of age between 1987 and 1992 and controlled for age and sex with healthy volunteers. RESULTS: We observed a significant increase in spontaneous heart rate (beats per minute) (67 ± 10 vs. 60 ± 10, p = 0.001), and all the studied parameters showed a significantly altered ANS activity in cases compared with healthy controls. In both groups, the main cofactors of dysautonomia (tobacco, drugs, cannabis, estro-progestative pills, alcohol, limited physical activity) were analyzed without any significant difference. The effect of cancer treatments received was not analyzed due to the small number of participants. CONCLUSION: The results showed a significant ANS dysfunction in childhood cancer survivors compared with healthy controls and suggested the value of autonomic screening to underscore and possibly quantify the effect of the cancer treatments in a larger cohort. This evaluation could lead to the recommendation to increase physical activity, the most efficient way known to improve ANS activity, as already shown in other pathologies (breast cancer).

Long-Term Follow-up Consultation After Childhood Cancer in the Rhône-Alpes Region of France: Feedback From Adult Survivors and Their General Practitioners.

PURPOSE: We evaluated the satisfaction of adult survivors of childhood cancers and their general practitioners (GP) after a long-term consultation. METHODS: The first Long-term Follow-up Study in Oncology (SALTO1) is a prospective cohort study of survivors of childhood cancers (except leukemia) diagnosed between 1987 and 1992 in the Rhône-Alpes and Auvergne regions of France. Of the 481 patients eligible for the study, 150 participated in a long-term consultation with a pediatric oncologist and an internist, after which survivors and their GPs received long-term plans and recommendations based on consultation findings. A year after the consultation, survivors and their GPs assessed their satisfaction with the process. RESULTS: Of the 150 survivor participants in the long-term follow-up, 120 (80%) completed the satisfaction form, with 107 (89%) reporting satisfaction. Forty-eight (32%) expressed strengthening their follow-up as a consequence of the consultation. Of the 79 survivors sent recommendations, 76 (96%) reported reading them, most (n = 68; 86%) found them useful, and 56 (71%) followed recommendations. Of the 107 GPs of the survivors, 82 (77%) conceded having been poorly informed about long-term complications for their patients after chemotherapy, and 93 (88%) appreciated having a hospital contact available for these patients. CONCLUSION: The long-term consultations ultimately enhanced medical follow-up of survivor participants, improving knowledge of both patients and family physicians regarding the patients' early disease, its treatments, and possible concerns, and offering consultative resources of medical specialists. The levels of participation of survivors and their physicians and reported satisfaction encourage the adoption of such consultations throughout France.