Epidemiological and clinical correlations with genetic characteristics of Wilms' tumor: Results of the Brazilian Wilms' tumor study group

Abstract

The epidemiological and clinical features of Wilms' tumor (WT) were analyzed in 176 patients admitted to the Brazilian WT Study Group. The occurrence of congenital anomalies (9.1%) and the M:F ratio (0.83) were comparable to those observed by the US National WT Study and the International Society of Pediatric Oncology trials. Bilateral cases were younger on average than unilateral cases (37.2 vs. 45.0 months). Ethnic group and gender were also associated with age, with non-white children being generally older (46.1 months) than whites (39.5 months), and boys being younger than girls (37.0 vs. 46.1 months). However, the most important factor in association with age at diagnosis was disease stage. No early disease patients were diagnosed after 8 years of age (mean: 37.5 months), whereas 10% of those with advanced disease were diagnosed between the ages of 8 and 10 years (mean: 56.3 months). There were no clear distinctions in age distributions on the basis of the presence of tumor multicentricity, intra- or perilobar nephroblastomatosis, and of a combination of putative genetic determinants. The mean age at diagnosis for cases with congenital defects was higher than that for the remaining patients. Some of the study results are in support of the recessive oncogene model for WT. However, the possible confounding effect of disease stage and the strong interdependence of the remaining factors may be masking important relations in regard to mutational events occurring during embryogenesis.

Wilms tumor: Experience of a hospital in southern Brazil

“…Assessing studies developed in Latin America, the objective of which was to highlight epidemiological WT data, we found nine: seven from Brazil, one from Mexico and one from Chile . Among the Brazilian ones, only one was of the Southern region, like the present study .…”

“…Among the Brazilian ones, only one was of the Southern region, like the present study . It is noteworthy that only one of these studies is listed in the international databases (PubMed; Table ) …”

“…As in the present study, those authors observed a higher frequency of birthweight between 3000 and 3999 g. High weight (≥4000 g) was observed in 12 patients (21.8%) compared to two (4.4%) in the present study. Regarding signs and symptoms, abdominal mass was the standout among Latin American studies, with a frequency between 67.6% and 100% …”

“…In Latin America there have been no studies on a significant number of cases of WT in order to report epidemiological data as well as prognosis, as has already done by the most important multicenter cooperative groups, the National Wilms' Tumor Study (NWTS; currently Children's Oncology Group [COG]) and the International Society of Paediatric Oncology (SIOP) in the USA and Europe, respectively. The first major epidemiological study of WT developed in Brazil was initiated in 1986 with the creation of the Brazilian Cooperative Group for the Treatment of WT . Studies such as this are important to characterize the presentation of the disease in a specific population and identify signs and symptoms that would aid in clinical diagnosis and management.…”

Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas

“…Mean age at diagnosis was similarly reported by other authors (2.98 years) (5) . The frequency of nephroblastomas is virtually equal in both genders, considering the fact that some studies evince a slight predominance in the female group, which was also confirmed in the present study (4,5,11) . As far as clinical presentations are concerned, the presence of abdominal mass was predominant (82.76%), which is similarly corroborated by the literature (17,20) .…”