Summary The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500 g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

IVF seems to be associated with increased risk of early onset ALL in the offspring.

As part of the European Union‐funded project designated Paediatric Rare Tumours Network ‐ European Registry (PARTNER), the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) is continuously developing consensus recommendations in order to harmonize standard care for very rare solid tumors of children and adolescents. This paper presents the internationally recognized recommendations for the diagnosis and treatment of sex cord stromal tumors (SCST). The clinical approach to sex cord stromal tumors of the testis (TSCST) and ovary (OSCST) depends on histological differentiation and tumor stage. Virtually all TSCSTs present as localized nonmetastatic tumors, with excellent prognosis after complete resection. In contrast, the prognosis of OSCSTs may be adversely affected by tumor spillage during surgery or presence of metastases. In these cases, cisplatin‐based chemotherapy is recommended. Of note, some SCSTs may develop in the context of tumor predisposition syndromes, for example, DICER‐1, so that specific follow‐up is indicated. SCSTs should be diagnosed and treated according to standardized recommendations that include reference pathology, genetic testing for tumor predisposition syndromes in selected cases, and stratified adjuvant chemotherapy in patients with unfavorable risk profile. To ensure high quality of diagnosis and therapy, patients should be enrolled into prospective registries.

Pilocytic astrocytomas (PA) comprise the most common childhood central nervous system (CNS) tumor. Exploiting registry-based data from Southern and Eastern Europe (SEE) and SEER, US, we opted to examine incidence, time trends, survival and tentative outcome disparities of childhood PA by sociodemographic and clinical features. Childhood PA were retrieved from 12 SEE registries (N = 552; 1983-2014) and SEER (N = 2723; 1973-2012). Age-standardized incidence rates (ASR) were estimated and survival was examined via Kaplan-Meier and Cox regression analysis. ASR of childhood PA during 1990-2012 in SEE was 4.2/10, doubling in the USA (8.2/10). Increasing trends, more prominent during earlier registration years, were recorded in both areas (SEE: +4.1 %, USA: +4.6 %, annually). Cerebellum comprised the most common location, apart from infants in whom supratentorial locations prevailed. Age at diagnosis was 1 year earlier in SEE, whereas 10-year survival was 87 % in SEE and 96 % in SEER, improving over time. Significant outcome predictors were age <1 year at diagnosis diagnosis (hazard ratio, HR [95% confidence intervals]: 3.96, [2.28-6.90]), female gender (HR: 1.38, [1.01-1.88]), residence in SEE (HR: 4.07, [2.95-5.61]) and rural areas (HR: 2.23, [1.53-3.27]), whereas non-cerebellar locations were associated with a 9- to 12-fold increase in risk of death. The first comprehensive overview of childhood PA epidemiology showed survival gains but also outcome discrepancies by geographical region and urbanization pointing to healthcare inequalities. The worse prognosis of infants and, possibly, females merits further consideration, as it might point to treatment adjustment needs, whereas expansion of systematic registration will allow interpretation of incidence variations.

Humoral immunity was depressed in children with ALL at the end of intensive therapy but began to recover after cessation of therapy. In contrast, cellular immunity declined significantly by the end of therapy and remained abnormal for at least 1 year post-therapy.

Despite definite survival gains over the last years, the considerable outcome disparities between the less affluent SEE region and the United States for AYAs with malignant CNS tumors point to health care delivery inequalities. No considerable prognostic deficits for CNS tumors are evident for AYAs versus children. Cancer 2017;123:4458-71. © 2017 American Cancer Society.

Pleuropulmonary blastoma (PPB) is a rare cancer occurring mainly during early childhood and often associated with germline DICER1 mutations. It is classified by the macroscopic appearance into three interrelated clinico‐pathologic entities on a developmental continuum. Complete tumor resection is a main prognostic factor and can be performed at diagnosis or after neoadjuvant treatment that includes chemotherapy and in some cases radiotherapy. Optimal modalities of neo‐ or adjuvant treatments can be challenging taking into account potential long‐term toxicities in this young population. This paper presents the recommendations for diagnosis and treatment of children and adolescents with PPB elaborated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the European Union‐funded project PARTNER (Paediatric Rare Tumours Network ‐ European Registry).

Purpose. Malignant peripheral nerve sheath tumors (MPNSTs) are rare in children and account for approximately 5–10% of all soft tissue sarcomas in adults. MPNSTs may occur independently but individuals with neurofibromatosis type 1 (NF1) have a significantly increased risk. Our aim is to present patients with MPNST treated in our department. Cases and Results. In this report we present 4 cases of MPNSTs (3 females: 13, 12, and 13 years old and 1 male: 10 years old) arising in patients with NF1. All of them presented with an enlarging mass and pain at diagnosis. Tumor was located in the buttock, the spinal cord, the trunk, and the left leg proximal to the heel. Wide excision of the tumor and radiotherapy were applied to all and adjuvant chemotherapy was given to three of them after the disease was progressed. All four died 32, 18, 10, and 22 months after diagnosis with progressive disease locally and pulmonary metastases in two of them. Conclusions. In conclusion, MPNSTs arising in patients with NF1 are high grade sarcomas with short survival. Individuals with NF1 should be followed closely in order to identify early the development of MPNSTs. Aggressive surgery and complete excision significantly improves disease-free survival. The usefulness of radiation therapy in MPNSTs is not determined although all patients will receive radiation therapy at some stage of the disease. The role of chemotherapy is unclear.