Clinical epidemiology of childhood cancer in Central America and Caribbean countries.

BACKGROUND: Countries with scarce resources have the right to appropriate essential health care but very few reports discuss how this can be achieved. We assessed the survival of a large cohort of pediatric oncological patients to provide hard data on which to base realistic evaluation and planning schemes. PATIENTS AND METHODS: This multicenter retrospective survey covered consecutively diagnosed and treated patients admitted to eight national level hospitals in seven countries in Central America and the Caribbean. The research protocol was discussed extensively, so the data to be collected and the criteria for their evaluation were clearly pre-defined. We analysed 2214 patients diagnosed between 1996 and 1999 with various cancers, classified as hemato-oncological disorders (70%) and solid tumors (30%). RESULTS: Three-year overall survival was 48.4% [standard error (SE) 1.3]. Detailed analysis of acute lymphoblastic leukemia highlighted the wide intercountry variability: 3-year survival was 62.2% (SE 5.3) in Cuba, 74.2% (SE 3.3) in Costa Rica, 61.7% (SE 4.9) in Nicaragua, and lower in the other four countries. CONCLUSIONS: The yield of diagnostic-therapeutic protocols depends largely on the context of care in which they are applied. This paper documents the importance of including epidemiological research in interventions for cooperation in complex health areas such as pediatric oncology.

Mutational activation of ras genes is absent in pediatric osteosarcoma.

Activation of ras oncogenes is found in human cancers; overall it is observed in 15% of all neoplasms. The purpose of this study was to assess the extent of involvement of ras oncogenes in osteosarcoma. Tumor samples from a series of 49 pediatric patients diagnosed with osteosarcoma and treated at our institution were evaluated. Paraffin-embedded tumor samples from diagnostic biopsies, from tumor en bloc resection tissue after neoadjuvant chemotherapy, and samples from metastases were examined in search of point mutations in H, K, and N-ras genes at codons 12 and 61 by means of polymerase chain reaction (PCR), slot-blotting, and radioactive labeled specific DNA probes. A total of 92 archival samples were studied. No point mutations activating these genes were found. These findings suggest that the activation by point mutations at codons 12 and 61 of the H, K, and N-ras genes does not play a role in the pathogenesis of human osteosarcoma. Since no point mutations in codons 12 and 61 were detected, it was not possible to establish any correlation between the ras genes and clinical or histologic findings.

[Malignant fibrous histiocytoma of the orbit as second tumor in a case of bilateral retinoblastoma]. / Histiocitoma fibroso maligno de la órbita como segundo tumor en un caso de retinoblastoma bilateral.

The case of a 30 months-old child with malignant fibrous histiocytoma of the left orbit diagnosed 18 months after treatment with external beam radiotherapy for bilateral retinoblastoma is presented. The clinical and histological characteristics of malignant fibrous histiocytoma and its relation as a second malignant tumor in patients affected with retinoblastoma are analyzed.

Copper deficiency and persistence of the ductus arteriosus.

An experimental model using rats is described, in which a state of copper deficiency was produced in pregnant dams and their offspring. In 100% of the neonates from the copper-deficient group (10/10), 20% (2/10) from the control group, and 40% (4/10) from the pair-fed group, the ductus arteriosus was found to remain patent. These figures were highly significant in statistical terms (X2 test; p less than 0.0009). The possible physiopathology of the persistence of the ductus arteriosus in copper-deficient neonates is discussed.

[Experience with the use of a subcutaneous venous access system in 57 pediatric patients]. / Experiencia con el uso de un sistema de acceso venoso subcutáneo en 57 pacientes pediátricos.

Since May of 1983 to December of 1988, 62 subcutaneous venous reservoires were implanted in 57 pediatric patients; 29 were boys and the remaining 28 were girls between the ages of 2 and 18 years. Fifty-one patients had malignant illnesses and seven other pathologies. The reservoir was used for the endovenous administration of cytotoxic chemotherapy and antibiotics, hidration, nutrition, the transfusion of blood product and the extraction of samples for laboratory tests. In our experience the most important complication was the infection of the system, on the average 0.06 episodes of infections occurred for every 100 days per reservoir. Other complications observed were less frequent. In our opinion the subcutaneous reservoir represents an useful tool for the care of the pediatric patients who require a central venous catheter for long periods of time.