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Retinoblastoma is the most frequent intra-ocular malignant tumor of the childhood, occurring in 1 of 18,000-30,000 live births. Little is known about the causes of sporadic retinoblastoma and only a few authors have investigated the etiologic role of human papillomavirus (HPV), with controversial results. Formalin-fixed, paraffin-embedded tissue blocks containing retinoblastoma were retrieved from the archives of the Department of Pathology at Hospital A C Camargo, São Paulo, Brazil. All patients were treated with enucleation (21 children had both eyes enucleated). Retinoblastoma and, when possible, normal retina of each specimen, were micro-dissected under direct light microscopic visualization by using a PixCell II Laser Capture Micro-dissection System. The DNA quality was evaluated by polymerase chain reaction (PCR) amplification of 110 base pairs fragment of the human β-globin gene using primers PCO3+/PCO4+. All globin positive specimens were analyzed by PCR for the presence of HPV DNA using consensus primers GP5+/GP6+. A total of 154 specimens were evaluated. Forty-four patients also had normal retinal specimens available for analysis of DNA HPV. The DNA HPV prevalence among all tumor specimens was 4.6% (95% CI 2.0; 8.8) (7 positive specimens/153 adequate specimens). Among normal retinal specimens, the DNA HPV prevalence was 9.1% (95% CI 2.9; 20.5) (4 positive specimens/44 specimens). There was no statistically significant difference between these rates (P = 0.318). Excluding any experimental failure, our results indicate a low prevalence of HPV DNA in retinoblastomas. We were therefore unable to conclude about the association between these oncogenic viruses and this rare pediatric neoplasm., (© 2010 Wiley-Liss, Inc.)

Background: Mutations of the tumor suppressor gene p53 are commonly found in several kinds of human cancer. In some types of neoplasms, accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior. The role of p53 expression in Wilms tumors (WT) is not clear yet, but most studies have confirmed its correlation with anaplasia and advanced stage disease., Procedure: Ninety-seven WT were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and correlated with outcome. Tumors were classified as p53-Negative (p53-N) when no positivity was observed or only few cells showed weak positivity (0/1+) and p53-Positive (p53-P) when there was a diffuse and strong nuclear positivity (2+/3+)., Results: p53-P was detected in 13 out of 97 tumors and was associated with disease relapse (39 vs.17%; P = 0.06) but not with anaplasia. Among p53-N patients only 5% had metastatic disease compared with 31% of the p53-P sample. (P = 0.038). Overall survival was 94% for patients with p53-N vs. 85% for patients with p53-P at 1 year (P = 0.34)., Conclusions: p53 expression in Wilms tumor detected by immunohistochemistry seems to be associated with advanced disease and relapse., (Copyright 2001 Wiley-Liss, Inc.)