Patients with Wilms tumour have benefited from the results of decades of large collaborative clinical trials, leading to improved care. In the National Wilms Tumor Study Group and now Children’s Oncology Group (COG) trials, risk stratification evolved and expanded with each generation of studies and, therefore, ensuring that each patient receives the appropriate therapy has become increasingly complex. A new risk stratification system has been developed that forms the basis of the upcoming COG favourable-histology Wilms tumour (FHWT) study. Topics of diagnostic and prognostic uncertainty, such as the findings of tumour pulmonary emboli or extra-abdominal lymphadenopathy at diagnosis, will be integrated into the central review determination of staging of FHWT by committee consensus to facilitate clinical classification for therapeutic studies. Clear documentation of the elements of current risk stratification are of particular importance as refinement of the classification of patients with FHWT continues in an effort to optimize research, personalize treatment and provide an educational resource.

The application of molecular tumor profiles in clinical decision making remains a challenge. To aid in the interpretation of complex biomarkers, molecular tumor boards (MTBs) have been established worldwide. In the present study, we show that a multidisciplinary approach is essential to the success of MTBs. Our MTB, consisting of pediatric oncologists, pathologists, and pharmacists, evaluated 115 cases diagnosed between March 2016 and September 2021. If targetable mutations were identified, pharmacists aided in the evaluation of treatment options based on drug accessibility. Treatable genetic alterations detected through molecular testing most frequently involved the cell cycle. For 85% of the cases evaluated, our MTB provided treatment recommendations based on the patient’s history and results of molecular tumor testing. Only three patients, however, received MTB-recommended targeted therapy, and only one of these patients demonstrated an improved clinical outcome. For the remaining patients, MTB-recommended treatment often was not administered because molecular tumor profiling was not performed until late in the disease course. For the three patients who did receive MTB-recommended therapy, such treatment was not administered until months after diagnosis due to physician preference. Thus, the education of healthcare providers regarding the benefits of targeted therapy may increase acceptance of these novel agents and subsequently improve patient survival.

Immunotherapy has emerged as a promising treatment approach in oncology, as it is specifically designed to boost the strength and accuracy of the immune system, allowing it to target tumor cells but spare non-tumor tissue. This treatment not only demonstrates potential for improved clinical outcomes but may also be associated with fewer adverse effects compared to traditional therapies. Despite its early success, the application of immunotherapy has largely been limited to adult cancer patients, with slow adoption noted in the treatment of pediatric cancer patients. Our objective is to demonstrate a single institution’s experience with immunotherapy in pediatric cancer patients and to discuss the use of these treatment modalities in this unique patient population. We performed a retrospective chart review and identified patients who received immune checkpoint inhibitors (ICIs) and/or underwent immunohistochemistry (IHC) testing for programmed death ligand 1 (PD-L1), quantification of tumor mutational burden (TMB), and classification of microsatellite instability (MSI) status. In total, we identified seven pediatric cancer patients who received therapy with ICIs. Four of these patients demonstrated positive PD-L1 expression, high TMB, and/or MSI-high status. These patients were treated with nivolumab alone or in combination with ipilimumab or brentuximab. The diagnoses included: multifocal epithelioid and spindle cell hemangioma (n = 1); metastatic melanoma (n = 2); histiocytic sarcoma (n = 1); rectal adenocarcinoma in the setting of constitutional mismatch repair deficiency syndrome (CMMRD) (n = 1); and Hodgkin lymphoma (n = 2). The patients received between four and nineteen cycles of immunotherapy. Immunotherapy-related adverse events included: mild allergic reaction; prodromal symptoms; anemia; neutropenia; transaminitis; endocrinopathies; and self-limiting neuritis. Of the seven patients, three are still being treated with immunotherapy (the patients with rectal adenocarcinoma, metastatic melanoma, and multifocal epithelioid and spindle cell hemangioma) with positive treatment responses observed on imaging, one is being treated with other modalities (the patient with Hodgkin lymphoma), two have achieved remission (the patients with metastatic melanoma and Hodgkin lymphoma), and one has relapsed (the patient with histiocytic sarcoma). The three patients who completed their immunotherapy regimens have been followed for 1 month, 4 months, and 10 months, respectively. This report of a single-institution experience with immunotherapy in pediatric cancer patients highlights the positive impact immunotherapy can have, especially when utilized to treat relapsed/refractory malignancies, as tumor regression or stabilization of disease burden was achieved in six of the patients described (CR = 2; PR = 4). Further research is needed to accurately identify pediatric oncology patients who could benefit from immunotherapy.

Advances in local control techniques, chemotherapy regimens, and imaging modalities have led to improvements in both morbidity and mortality in pediatric sarcoma patients. However, approximately one-third of patients develop disease relapse and intracranial metastasis was considered rare. The incidence of sarcoma brain metastasis is thought to have increased and is associated with grim outcomes. This was a retrospective study of 3 deidentified patient charts illustrating the possibility of the central nervous system as a potential site for pediatric sarcoma relapse and investigate the patterns of such relapses. We note this is the first report of infantile fibrosarcoma brain metastasis and a rare report of sarcoma lymph node metastasis. In addition, each patient was treated with targeted therapies, including entrectinib, Ruxolitnib, and pazopanib. Caregivers in cases 2 and 3 reported new-onset neurological manifestations before identification of new brain metastasis, indicating a lag in detection of new intracranial relapse in asymptomatic sarcoma patients. We suggest implementing a brief review of systems screening tool focused on concerning neurological manifestations to screen for new brain metastasis.