Precision based approach to tailoring radiotherapy in the multidisciplinary management of pediatric central nervous system tumors

Modern day survivorship from childhood malignancies is estimated to be over 80%.However,central ner-vous system tumors remain the leading cause of cancer mortality in children and is the most common solid tumor in this population.Improved survivorship is,in part,a result of improved multidisciplinary care,of-ten with a combination of surgery,radiation therapy,and systemic therapy.With improved survival,long term effects of treatment and quality of life impacts have been recognized and pose a challenge to maxi-mize the therapeutic ratio of treatment.It has been increasingly more apparent that precise risk stratifica-tion,such as with the inclusion of molecular classification,is instrumental in efforts to tailor radiotherapy for appropriate treatment,generally towards de-intensification for this vulnerable patient population.In ad-dition,advances in radiotherapy techniques have allowed greater conformality and accuracy of treatment for those who do require radiotherapy for tumor control.Ongoing efforts to tailor radiotherapy,including de-escalation,omission,or intensification of radiotherapy,continue to improve as increasing insight into tumor heterogeneity is recognized,coupled with advances in precision medicine employing novel molecularly-targeted therapeutics.

Microsatellite instability and expression of DNA mismatch repair genes in malignant astrocytic tumors from adult and pediatric patients

Microsatellite instability (MSI) is used as a molecular marker for defective DNA mismatch repair (MMR) genes.We report here alterations of MSI in 15 malignant astrocytomas (WHO grade Ⅲ) and glioblastomas (GBM; WHO grade Ⅳ) of pediatric patients (2-21 years) and 12 GBM from adults (44-68 years) by comparative analysis of BAT25/BAT26 loci and 10 other microsatellite markers. High-level microsatellite instability (MSI-H) occurred in 4 of the 15 pediatric cases (26.7%) and in 1 of the 12 adult GBM cases (8.3%). Low-level mi-

Chronic hepatitis B in children with or without malignancies:A 13-year follow-up

AIM:To evaluate the outcome of chronic hepatitis B(CHB)in children with or without malignancies.METHODS:Twenty four children(15 boys and 9 girls)with malignancies,followed up by the pediatric gastroenterology outpatient clinic for CHB between January 2000 and December 2013,were enrolled in the study(Group 1).Group 2 was formed with twenty five children(11 girls and14 boys)diagnosed with CHB without malignancies.The data from the patients’records were compared between the two groups.RESULTS:Hepatitis B e antigen(HBe Ag)/anti HBe seroconversion was observed in 3 patients(12.5%)in group 1 and 15 patients(60%)in group 2,with annual seroconversion rates of 1.61%and 16.6%,respectively,and the difference was significant(P<0.01).One patient(6.6%)in Group 1 and 9 patients(53%)in Group 2 showed HBe Ag/anti HBe seroconversion after treatment and the difference between the two groups was significant(P<0.06)Loss of hepatitis B surface antigen was observed in one patient in each of group1 and 2.No clinical,laboratory and imaging findings of liver disease were observed in any of the patients at the end of the study.CONCLUSION:HBe Ag/anti HBe seroconversion rate was lower in patients who had recovered from cancer.