No 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.

Ninety-four soft-tissue sarcomas of head and neck occurring among 10,700 malignancies, seen during the period 1953-1980 in the head-and-neck surgical department, were studied with reference to age, sex, ethnic origin, site, histological type and survival. The objective was to review our own experience with sarcomas in these sites seen in the Department of Pathology, A.C. Camargo Hospital. The predominant site was the head. Fibrosarcoma was the most frequent type in adults and rhabdomyosarcoma, located exclusively in the head, was the most frequent in children.

Summary We examined loss of heterozygosity (LOH) for two loci on chromosome 17p (D17S5 and TP53), and erbB-2 gene amplification, in primary breast cancers from 67 Brazilian patients. We identified two distinct regions of LOH on chromosome 17p, one spanning TP53 and the other a more telomeric region (D17S5). Based on a short-term follow-up, Kaplan-Meier analyses of patients' disease-free survival showed that patients with LOH for D17S5, but retaining heterozygosity for TP53, were at higher risk of recurrence (P = 0.007) than those who retained heterozygosity for D17S5. Bivariate analyses indicated that patients with LOH for D17S5 alone had an increased risk of recurrence (hazard ratio = 7.2) over patients with erbB-2 amplification (hazard ratio = 3.7), when compared with patients with neither alteration (hazard ratio = 1.0). Further, lymph node-positive patients whose tumours had both LOH for D17S5 and erbB-2 gene amplification had a higher risk of recurrence than patients whose tumours had neither of these genetic alterations. Our data confirm previous reports of a putative tumour-suppressor gene, distinct from TP53, on distal chromosome 17p which is associated with breast cancer. They further suggest that LOH for loci in this region may provide an independent indicator to identify patients with poor prognosis.

Chemotherapy with oxazaphosphorines, such as ifosfamide, is often limited by unacceptable urotoxicity. Without uroprotection hemorrhagic cystitis becomes dose-limiting. Mesna, a thiol compound, is a drug able to bind the toxic metabolites, forming nontoxic compounds in the urine. A total of 122 patients were enrolled in this study and 228 chemotherapy cycles with an ifosfamide-containing regimen were performed (225 evaluable). Mesna was given at the same total dose as the ifosfamide in all arms. On arm A, mesna was given i. v. in equal doses 15 min before and 4 h and 8 h following the ifosfamide dose. On arm B, mesna was given in three equivalent doses 15 min before (i.v.) and 4 h (i.v.) and 8 h (p.o., double dose) following ifosfamide. On arm C, mesna was given i.v. in two equal doses given 15 min before and 4 h following. The incidence of urotoxicity was very low (lower than 15%) in the three arms, 0% in A, 1.36% in B and 2.70% in C. All three arms were equally efficient. Schedule C was considered superior to the others, since it was equally effective, simpler and more convenient.