Therapy for Vitreous Seeding Caused by Retinoblastoma. A Review.

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma. This article presents an overview of the history of vitreous seeding of retinoblastoma, established treatment procedures and new-research modalities. The introduction of systemic chemotherapy in the treatment of retinoblastoma at the end of the 1990s represented a significant breakthrough, which enabled the progressive abandonment of radiotherapy with its attendant side effects. However, the attained concentrations of chemotherapeutics in the vitreous space during systemic chemotherapy are not sufficient for the treatment of vitreous seeding, and the toxic effects of systemic chemotherapy are not negligible. A significant change came with the advent of chemotherapy in situ, with the targeted administration of chemotherapeutic drugs, namely intra-arterial and intravitreal injections, contributing to the definitive eradication of external radiotherapy and a reduction of systemic chemotherapy. Although vitreous seeding remains the most common reason for the failure of intra-arterial chemotherapy, this technique has significantly influenced the original treatment regimen of children with retinoblastoma. However, intravitreal chemotherapy has made the greatest contribution to increasing the probability of preservation of the eyeball and visual functions in patients with advanced findings. Novel local drug delivery modalities, gene therapy, oncolytic viruses and immunotherapy from several ongoing preclinical and clinical trials may represent promising approaches in the treatment of vitreous retinoblastoma seeding, though no clinical trials have yet been completed for routine use.

Therapy for Vitreous Seeding Caused by Retinoblastoma. A Review.

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a  major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma. This article presents an overview of the history of vitreous seeding of retinoblastoma, established treatment procedures and new-research modalities. The introduction of systemic chemotherapy in the treatment of retinoblastoma at the end of the 1990s represented a  significant breakthrough, which enabled the progressive abandonment of radiotherapy with its attendant side effects. However, the attained concentrations of chemotherapeutics in the vitreous space during systemic chemotherapy are not sufficient for the treatment of vitreous seeding, and the toxic effects of systemic chemotherapy are not negligible. A significant change came with the advent of chemotherapy in situ, with the targeted administration of chemotherapeutic drugs, namely intra-arterial and intravitreal injections, contributing to the definitive eradication of external radiotherapy and a reduction of systemic chemotherapy. Although vitreous seeding remains the most common reason for the failure of intra-arterial chemotherapy, this technique has significantly influenced the original treatment regimen of children with retinoblastoma. However, intravitreal chemotherapy has made the greatest contribution to increasing the probability of preservation of the eyeball and visual functions in patients with advanced findings. Novel local drug delivery modalities, gene therapy, oncolytic viruses and immunotherapy from several ongoing preclinical and clinical trials may represent promising approaches in the treatment of vitreous retinoblastoma seeding, though no clinical trials have yet been completed for routine use.

[Hepatoblastoma, Etiology, Case Reports]. / Hepatoblastom, etiologie, kazuistiky.

Hepatoblastoma is an uncommon malignant neoplasm in general, yet, it is the most common liver malignancy in children with the incidence about one per milion children. This type of liver tumor usually occurs before the age of three years. The etiology of hepatoblastoma remains unknown. However, there are some genetic conditions known to be associated with an increased risk of developing hepatoblastoma such as Beckwith-Wiedemann syndrome, hemihypertrophy, APC-associated polyposis, α-1-antitrypsin defficiency and some metabolic disorders including tyrosinemia, galactosemia and glycogen storage disease type 1. There is a higher risk of hepatoblastoma in children with very low birthweight, children who acquire hepatitis B at an early age and children with congenital biliary atresia.

[Fanconi Anemia, Complementation Group D1 Caused by Biallelic Mutations of BRCA2 Gene--Case Report]. / Fanconiho anémie, komplementacní skupina D1 v dusledku bialelické mutace genu BRCA2--kazuistika.

Fanconi anemia is a rare autosomal recessive disorder, clinically and genetically heterogeneous, characterized by typical clinical features, such as short stature, microcephaly, skeletal abnormalities, abnormal skin pigmentations, developmental delay and congenital heart, kidney anomalies etc. Pancytopenia leading to bone marrow failure occurs in the first decade. Patients with Fanconi anemia have a high risk of hematologic malignancies and solid tumors. The diagnosis of Fanconi anemia is based on cytogenetic testing for increased rates of spontaneous chromosomal breakage and increased sensitivity to diepoxybutane or mitomycin C. Fanconi anemia is a heterogeneous disorder, at least 15 complementation groups are described, and 15 genes in which mutations are responsible for all of the 15 Fanconi anemia complementation groups have been identified. Unlike other Fanconi anemia complementation groups, for complementation group D1 (FANCD1), the bone marrow failure is not a typical feature, but early-onset leukemia and specific solid tumors, most often medulloblastoma and Wilms tumor, are typical for this complementation group.

[Nephroblastoma -  30-years period of its treatment in the University Hospital Motol, Prague]. / Nefroblastom -  30 let lécby ve Fakultní nemocnici v Motole.

INTRODUCTION: Nephroblastoma (Wilms tumor - WT) is the most common solid tumor of kidney in children. We present treatment development of WT at the Department of Pediatric Hematology and Oncology, Charles University in Prague, 2nd Faculty of Medicine and University Hospital Motol (KDHO) in the Czech Republic over 30 years. Patients that were treated prior to access to the International Society of Pediatric Oncology (SIOP) protocols are considered to be the historical group, then we have patients treated according to SIOP 9, SIOP 93-01 and SIOP 2001 protocols as full participants of SIOP studies. PATIENTS AND METHODS: Between January 1980 and April 2009, we treated 330 patients with WT at KDHO: 91 patients in historical group (1980-1988), 94 pts in SIOP 9 (1988-1993), 80 pts in SIOP 93-01 (1994-2001) and 65 pts in SIOP 2001 (2002-2009). Overall survival (OS) and event-free survival (EFS) were analyzed by Kaplan-Meier test. RESULTS: The overall ten-year EFS was 81.2% and OS 87.6%. Fifty-eight patients from the 330 (17.6%) had metastases at diagnosis, EFS without metastatic process was 84.6% compared to 65.4% with metastasis presented at diagnosis (p = 0.0003), OS was 70.7% compared to 91.2% (p < 0.0001). One hundred and seventy patients (51.5%) were treated with preoperative chemotherapy and/or radiotherapy, whereas 158 patients (47.5%) underwent primary nephrectomy; EFS and OS did not differ: neoadjuvant vs primary nephrectomy EFS was 81.2% vs 80.9% (p = 0.85), OS 89.4% vs 85.4% (p = 0.38). Sixty (18%) patients experienced disease recurrence; OS after relapse was 33%. In the historical group, EFS and OS were 85.7% and 91.2%. In patients treated according to the SIOP 9 protocol, EFS and OS were 68.1% and 74.5%, resp. In patients treated according to SIOP 93-01, it was 83.6% and 93.7%, resp. and in patients treated according to 87 SIOP 2001, it was 7% and 95.4% (p = 0.001 and p = 0.0008), resp. CONCLUSION: WT is a well treatable disease. The aim for the future is to maintain the current very good survival while minimizing the treatment intensity.