Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

The impact of cooperative group studies on childhood cancer: Improving outcomes and quality and international collaboration

The advances in pediatric cancer far exceed those achieved in adults. The success in improving survival and minimizing late effects has been due to several reasons but work of the pediatric cancer cooperative groups is a primary. These cooperative groups are multidisciplinary with medical oncologists, pathologists, radiologists, surgeons, radiation oncologists, scientists and most importantly the patients and families. Studies have expanded from regional to national and now international studies which continue to target problems pertinent to improving the outcome for children with cancer. In this article we review the history of the cooperative groups, a selection of seminal studies pertaining to solid tumors, future challenges and collaborations.

Update on Wilms tumor

This article reviews of the current evidence-based treatment standards for children with Wilms tumor. In this article, a summary of recently completed clinical trials by the Children's Oncology Group is provided, the current diagnostic evaluation and surgical standards are discussed, and the surgical impact on current risk stratification for patients with Wilms tumor is highlighted. LEVEL OF EVIDENCE: This is a review article of previously published and referenced LEVEL 1 studies, but also includes expert opinion LEVEL V, represented by the American Pediatric Surgical Association Cancer Committee.

Cardiac-Sparing Whole Lung Intensity Modulated Radiation Therapy in Children With Wilms Tumor: Final Report on Technique and Abdominal Field Matching to Maximize Normal Tissue Protection

PURPOSE

Cardiac-sparing whole lung intensity modulated radiation therapy (WL IMRT) has been shown to improve cardiac protection and lung volume dose coverage compared with standard anteroposterior techniques. This dosimetry study had 2 aims: To determine the dosimetric advantages of a modified WL IMRT (M-WL IMRT) technique, designed to reduce radiation exposure to the thyroid gland and breast tissues, compared with standard WL IMRT (S-WL IMRT) and to determine the dosimetric advantages of M-WL IMRT and dosimetrically matched abdomen and flank radiation therapy (RT) fields designed to reduce normal tissue exposure compared with standard field matching techniques.

METHODS AND MATERIALS

Computed tomography scans of the chest and abdomen that were obtained during computed tomography simulation of 10 female children were used. For Aim 1, for S-WL IMRT, the planning target volume (PTV) was obtained with a 1-cm expansion of the 4-dimensional lung volume (internal target volume). For M-WL IMRT, the PTV was reduced around the breast and thyroid gland to facilitate thyroid and breast sparing. For Aim 2, standard matching techniques for 3-dimensional anterior/posterior-posterior/anteriorwhole lung and abdominal RT fields were compared with a new dosimetric matching technique for WL IMRT and abdomen and flank fields. For both aims, the dose coverage of the lungs and radiation exposure to normal tissues (heart, thyroid, breasts) were statistically compared.

RESULTS

Compared with S-WL IMRT, the M-WL IMRT technique provided similar lung PTV dose coverage and a significantly superior reduction in mean breast and thyroid doses, without compromising cardiac protection. The M-WL IMRT technique combined with a dosimetrically matched abdomen and flank fields showed significantly superior normal tissue protection compared with standard matched anterior/posterior-posterior/anteriorlung and abdomen and flank RT fields.

CONCLUSIONS

This study has shown that the M-WL IMRT technique can reduce radiation exposure to the thyroid gland and breast tissue without compromising cardiac protection and 4-dimensional lung volume dose coverage. This report also describes a new dosimetric matching technique between WL IMRT and abdomen and flank fields that will improve normal tissue sparing compared with standard techniques.

The Children's Oncology Group Radiation Oncology Discipline: 15 Years of Contributions to the Treatment of Childhood Cancer

PURPOSE

Our aim was to review the advances in radiation therapy for the management of pediatric cancers made by the Children's Oncology Group (COG) radiation oncology discipline since its inception in 2000.

METHODS AND MATERIALS

The various radiation oncology disease site leaders reviewed the contributions and advances in pediatric oncology made through the work of the COG. They have presented outcomes of relevant studies and summarized current treatment policies developed by consensus from experts in the field.

RESULTS

The indications and techniques for pediatric radiation therapy have evolved considerably over the years for virtually all pediatric tumor types, resulting in improved cure rates together with the potential for decreased treatment-related morbidity and mortality.

CONCLUSIONS

The COG radiation oncology discipline has made significant contributions toward the treatment of childhood cancer. Our discipline is committed to continuing research to refine and modernize the use of radiation therapy in current and future protocols with the goal of further improving the cure rates and quality of life of children with cancer.

Position paper: Rationale for the treatment of Wilms tumour in the UMBRELLA SIOP-RTSG 2016 protocol

The Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new protocol for the diagnosis and treatment of childhood renal tumours, the UMBRELLA SIOP-RTSG 2016 (the UMBRELLA protocol), to continue international collaboration in the treatment of childhood renal tumours. This protocol will support integrated biomarker and imaging research, focussing on assessing the independent prognostic value of genomic changes within the tumour and the volume of the blastemal component that survives preoperative chemotherapy. Treatment guidelines for Wilms tumours in the UMBRELLA protocol include recommendations for localized, metastatic, and bilateral disease, for all age groups, and for relapsed disease. These recommendations have been established by a multidisciplinary panel of leading experts on renal tumours within the SIOP-RTSG. The UMBRELLA protocol should promote international collaboration and research and serve as the SIOP-RTSG best available treatment standard.

Wilms Tumor With Metastasis to the Vagina: A Case Report

A 12-year-old female presented with abdominal pain, night sweats, weight loss, constipation, dysmenorrhea, menorrhagia, and vaginal discharge. Examination revealed a palpable flank mass and a large tumor adherent to the anterior vaginal wall. Computed tomography scan demonstrated a 23 cm mass in the left kidney, a separate 10.8 cm pelvic mass, and metastatic disease. Biopsies were consistent with Wilms tumor. Neoadjuvant chemotherapy and a left radical nephrectomy were performed for her stage IV disease as the kidney was amiable to complete resection. The patient received radiation and resumed chemotherapy. She was doing well with improved symptoms at follow-up.

Wilms tumor: "State-of-the-art" update, 2016

Despite an impressive increase in survival rate over the past decades, there is still a need to improve the survival of specific subgroups of Wilms tumor (anaplastic, metastatic, and bilateral) and to decrease the late effects of treatment in terms of renal function and heart toxicity. We aim to explore new areas of improvement, from diagnosis to treatment: in the field of radiology the increased use of MRI and exploration of its diffusion-weighted imaging capabilities to predict WT histology at diagnosis and for preoperative assessment; in biology the emergence of new biomarkers that could be integrated into the decision-making process; and surgical techniques with more accurate indication of nephron-sparing surgery that is no longer reserved for bilateral WT and the minimally invasive approach. The long-term outcome of patients with WT should thus be a strong indicator of the improvement in adapting and personalizing the treatment to each individual.

Considerations in the Diagnosis and Management of Pediatric Patients With Favorable Histology Wilms Tumor Who Present With Only Pulmonary Nodules

More than 70% of children with stage IV, favorable histology (FH) Wilms tumor will be relapse-free survivors 16 years after diagnosis. Successful treatment generally includes whole lung radiation therapy and doxorubicin. Such therapy is associated with adverse, long-term effects, including impaired pulmonary function, congestive heart failure, and second malignant neoplasms, especially breast cancer. Cooperative groups have adopted a risk-based approach to the treatment of these patients. It is important to recall the good overall prognosis for this group before recommendations for intensification are made based on preliminary data and in the absence of histological confirmation of persistent malignant disease.