Retinoblastoma in a pediatric oncology reference center in Southern Brazil.

BACKGROUND: Retinoblastoma (Rb) is the most common intraocular tumor diagnosed in children in Brazil. However, detailed information is lacking regarding patient clinical demographics. This study aimed to determine the clinical profile of patients with Rb who were treated in a public university hospital in southern Brazil from 1983 to 2012. METHODS: Patients' medical records were reviewed to retrospectively identify patients with a principal diagnosis of Rb. Rb was classified as hereditary or non-hereditary. Clinical staging was reviewed by an ophthalmologist. Statistical analysis was performed using SPSS. RESULTS: Of 165 patients with a diagnosis of Rb during this period, 140 were included in the study. Disease was unilateral in 65.0 % of patients, bilateral in 32.9 %, and trilateral in 2.1 %. The mean age at onset of the first sign/symptom was 18.1 month, and 35.7 % of patients were diagnosed during the first year of life. The most common presenting signs were leukocoria (73.6 %) and strabismus (20.7 %). The mean age at diagnosis was 23.5 months, and time to diagnosis was 5.4 months. In patients with clinical features of hereditary Rb, both onset of the first sign/symptom and diagnosis were at an earlier age than in patients without these features (12.3 vs 21.6 months [P = 0.001] and 15.9 vs 28.0 months [P < 0.001], respectively). However, there was no significant difference in overall survival between the two groups. Ocular stage at diagnosis was advanced in 76.5 % (Reese V) and 78.1 % (International Classification D or E). Of patients with unilateral and bilateral disease, 35.2 % and 34.8 %, respectively, had extraocular disease at diagnosis; 10.7 % had metastatic disease at diagnosis. Enucleation was observed in 88.1 % and exenteration in 11.9 % of patients; 93.6 % patients were followed until 2012, and 22.9 % relapsed. Overall survival was 86.4 %. CONCLUSIONS: Most Rb diagnoses are still diagnosed in advanced stages of the disease, considerably reducing overall survival time and the rate of eye and vision preservation.

Li-Fraumeni and Li-Fraumeni-like syndrome among children diagnosed with pediatric cancer in Southern Brazil.

BACKGROUND: Pediatric cancers are a feature in patients with Li-Fraumeni syndrome and its variant Li-Fraumeni-like syndrome (LFS/LFL). To the best of the authors' knowledge, TP53 germline mutations are currently the only molecular defect known to be associated with this disease. Recently, a specific germline mutation in this gene, p.R337H, has been reported at a high prevalence in Brazil. METHODS: The prevalence of LFS/LFL was investigated in children with cancer who were diagnosed with tumors on the LFS/LFL spectrum and in a small consecutive series of controls without cancer. The prevalence of the germline p.R337H mutation and of other germline TP53 mutations was investigated in a general group of children with cancer and exclusively in children fulfilling the clinical criteria for LFS/LFL, respectively. RESULTS: Among the 65 children without cancer, 1.5% had a family history of LFL whereas of the 292 children with cancer, 25.3% had a family history of LFL (P < .001). Screening for the p.R337H mutation identified 11 carriers (3.7%), 9 of whom were diagnosed with adrenocortical carcinomas (ACC) and 2 of whom were diagnosed with choroid plexus carcinomas. One of the ACC probands was homozygous mutant. The Brazilian founder haplotype and loss of heterozygosity at the p.R337H locus were present in all carriers. In addition, direct sequencing of the entire TP53 coding region and gene rearrangement analysis of probands fulfilling the criteria for LFL (Eeles 2 criteria, Birch and/or Chompret criteria) and who were negative for the p.R337H mutation revealed a DNA-binding domain pathogenic mutation, p.G245S, in 1 child. CONCLUSIONS: TP53 p.R337H testing should be offered to Brazilian children diagnosed with ACC and choroid plexus carcinoma. A significant percentage of children with cancer in southern Brazil fulfill the criteria for LFL and should be referred for genetic risk assessment.

MIR605 rs2043556 is associated with the occurrence of multiple primary tumors in TP53 p.(Arg337His) mutation carriers.

Li-Fraumeni and Li-Fraumeni-like (LFS/LFL) Syndrome are cancer predisposition syndromes caused by germline pathogenic variants in TP53 and are associated with an increased risk of multiple early-onset cancers. In Southern and Southeastern Brazil, a germline founder variant with partial penetrance located in the oligomerization domain of TP53, c.1010G>A p.(Arg337His, commonly known as R337H), has been detected in 0.3% of the general population. Recently, the functional MIR605 variant rs2043556 (A>G) has been identified as a novel LFS phenotype modifier in families with germline TP53 DNA binding variants. In this study, our goal was to verify MIR605 rs2043556 allele frequencies and further explore its possible effects on the phenotype of 238 Brazilian individuals carrying TP53 p.(Arg337His). The MIR605 rs2043556 G allele was detected in 136 (57.1%) individuals, including 25 homozygotes (10.5%), and although it had been previously associated with an earlier mean age of tumor onset, this effect was not observed in this study (p = 0.8). However, in p.(Arg337His) mutation carriers, the GG genotype was significantly associated with the occurrence of multiple primary tumors (p = 0.005). We provide further evidence of MIR605 rs2043556 G allele's effect as a phenotype modulator in carriers of germline TP53 pathogenic variants.

The germline mutational landscape of BRCA1 and BRCA2 in Brazil.

The detection of germline mutations in BRCA1 and BRCA2 is essential to the formulation of clinical management strategies, and in Brazil, there is limited access to these services, mainly due to the costs/availability of genetic testing. Aiming at the identification of recurrent mutations that could be included in a low-cost mutation panel, used as a first screening approach, we compiled the testing reports of 649 probands with pathogenic/likely pathogenic variants referred to 28 public and private health care centers distributed across 11 Brazilian States. Overall, 126 and 103 distinct mutations were identified in BRCA1 and BRCA2, respectively. Twenty-six novel variants were reported from both genes, and BRCA2 showed higher mutational heterogeneity. Some recurrent mutations were reported exclusively in certain geographic regions, suggesting a founder effect. Our findings confirm that there is significant molecular heterogeneity in these genes among Brazilian carriers, while also suggesting that this heterogeneity precludes the use of screening protocols that include recurrent mutation testing only. This is the first study to show that profiles of recurrent mutations may be unique to different Brazilian regions. These data should be explored in larger regional cohorts to determine if screening with a panel of recurrent mutations would be effective.

Pediatric cancer and Li-Fraumeni/Li-Fraumeni-like syndromes: a review for the pediatrician.

INTRODUCTION: cancer is the second leading cause of death in children between the ages of 0 and 14 years, corresponding to approximately 3% of all cases diagnosed in Brazil. A significant percentage (5-10%) of pediatric cancers are associated with hereditary cancer syndromes, including Li-Fraumeni/Li-Fraumeni-like syndromes (LFS/LFL), both of which are caused by TP53 germline mutations. Recent studies have shown that a specific TP53 mutation, known as p.R337H, is present in 1 in 300 newborns in Southern and Southeast Brazil. In addition, a significant percentage of children with LFS/LFL spectrum tumors in the region have a family history compatible with LFS/LFL. OBJECTIVE: to review clinical relevant aspects of LFS/LFL by our multidisciplinary team with focus on pediatric cancer. METHODS: the NCBI (PubMed) and SciELO databases were consulted using the keywords Li-Fraumeni syndrome, Li-Fraumeni-like syndrome and pediatric cancer; and all manuscripts published between 1990 and 2014 using these keywords were retrieved and reviewed. CONCLUSION: although LFS/LFL is considered a rare disease, it appears to be substantially more common in certain geographic regions. Recognition of population- specific risks for the syndrome is important for adequate management of hereditary cancer patients and families. In Southern and Southeastern Brazil, LFS/ LFL should be considered in the differential diagnosis of children with cancer, especially if within the spectrum of the syndrome. Due to the complexities of these syndromes, a multidisciplinary approach should be sought for the counseling, diagnosis and management of patients and families affected by these disorders. Pediatricians and pediatric oncologists in areas with high prevalence of hereditary cancer syndromes have a central role in the recognition and proper referral of patients and families to genetic cancer risk evaluation and management programs.

The breast cancer immunophenotype of TP53-p.R337H carriers is different from that observed among other pathogenic TP53 mutation carriers.

Germline TP53 mutations are associated with Li-Fraumeni syndrome, an autosomal dominant disorder characterized by a predisposition to multiple early-onset cancers including breast cancer (BC), the most prevalent tumor among women. The majority of germline TP53 mutations are clustered within the DNA-binding domain of the gene, disrupting the structure and function of the protein. A specific germline mutation in the tetramerization domain of p53, p.R337H, was reported at a high frequency in Southern and Southeastern Brazil. This mutation appears to result in a more subtle defect in the protein, which becomes functionally deficient only under particular conditions. Recent studies show that the BC phenotype in TP53 mutation carriers is often HER2 positive (63-83%). Considering that the immunophenotype of BC among p.R337H carriers has not been reported, we reviewed immunohistochemistry data of 66 p.R337H carriers in comparison with 12 patients with other non-functional TP53 germline mutation. Although 75% of carriers of these mutations showed significant HER2 overexpression (3+), corroborating previous studies, only 22.7% of p.R337H patients had BC overexpressing HER2. These results reinforce the notion that different germline mutations in TP53 may predispose to BC via different mechanisms.

Pediatric cancer and Li-Fraumeni/Li-Fraumeni-like syndromes: a review for the pediatrician / Câncer pediátrico e síndrome de Li-Fraumeni/Li-Fraumeni- like: uma revisão para o pediatra.

Summary Introduction: cancer is the second leading cause of death in children between the ages of 0 and 14 years, corresponding to approximately 3% of all cases diagnosed in Brazil. A significant percentage (5-10%) of pediatric cancers are associated with hereditary cancer syndromes, including Li-Fraumeni/Li-Fraumeni-like syndromes (LFS/LFL), both of which are caused by TP53 germline mutations. Recent studies have shown that a specific TP53 mutation, known as p.R337H, is present in 1 in 300 newborns in Southern and Southeast Brazil. In addition, a significant percentage of children with LFS/LFL spectrum tumors in the region have a family history compatible with LFS/LFL. Objective: to review clinical relevant aspects of LFS/LFL by our multidisciplinary team with focus on pediatric cancer. Methods: the NCBI (PubMed) and SciELO databases were consulted using the keywords Li-Fraumeni syndrome, Li-Fraumeni-like syndrome and pediatric cancer; and all manuscripts published between 1990 and 2014 using these keywords were retrieved and reviewed. Conclusion: although LFS/LFL is considered a rare disease, it appears to be substantially more common in certain geographic regions. Recognition of population- specific risks for the syndrome is important for adequate management of hereditary cancer patients and families. In Southern and Southeastern Brazil, LFS/ LFL should be considered in the differential diagnosis of children with cancer, especially if within the spectrum of the syndrome. Due to the complexities of these syndromes, a multidisciplinary approach should be sought for the counseling, diagnosis and management of patients and families affected by these disorders. Pediatricians and pediatric oncologists in areas with high prevalence of hereditary cancer syndromes have a central role in the recognition and proper referral of patients and families to genetic cancer risk evaluation and management programs. .

Resumo Introdução: o câncer é a segunda principal causa de morte em crianças com idades entre 0 e 14 anos, correspondendo a cerca de 3% de todos os casos diagnosticados no Brasil. Um percentual significativo (5-10%) dos cânceres pediátricos são associados a síndromes hereditárias para câncer, incluindo Li-Fraumeni/Li-Fraumeni-like síndromes (LFS/LFL), causadas por mutações germinativas no gene TP53. Estudos recentes têm demonstrado que uma mutação específica em TP53, conhecida como p.R337H, está presente em 1 em 300 recém-nascidos no Sul e Sudeste do Brasil. Além disso, um percentual significativo de crianças com tumores do espectro LFS/LFL na região têm uma história familiar compatível com a síndrome. Objetivos: revisão dos aspectos clínicos relevantes da LFS/LFL por equipe multidisciplinar, com foco no câncer pediátrico. Métodos: o NCBI (PubMed) e SciELO foram consultados, usando as palavras-chave síndrome de Li-Fraumeni, síndrome de Li-Fraumeni-like e câncer pediátrico. Todos os artigos publicados entre 1990 e 2014 usando essas palavras- chave foram recuperados e revisados. Conclusão: apesar de LFS/LFL ser considerada uma doença rara, ela parece ser mais frequente em certas regiões. Reconhecer os critérios e condutas para identificação de pacientes em risco para LFS/LFL é fundamental para o manejo adequado dos pacientes com câncer hereditários e suas famílias. Devido à complexidade dessas síndromes, a abordagem multidisciplinar deve ser realizada. Pediatras e oncologistas pediátricos em áreas com alta prevalência de síndromes hereditárias de câncer têm um papel central no reconhecimento e encaminhamento adequado dos pacientes e famílias para programas de avaliação do risco de câncer genético e de gestão. .

Estimativa de risco de câncer de mama, índice de massa corporal e densidade mamária em uma população de mulheres carentes submetida a rastreamento de mamografia / Breast cancer risk estimates, body mass index and breast density in women submitted to mammographic screening in an underserved population

Vários modelos de estimativa do risco de câncer de mama foram criados e, entre estes, o modelo de Gail é comumente usado; no entanto, em mulheres latino-americanas submetidas a rastreamento mamográfico, não há estudos sobre o seu desempenho. Os objetivos do presente estudo foram estimar o risco de câncer de mama, utilizando o modelo de Gail 2 e verificar a prevalência de fatores de risco para a doença (índice de massa corporal, densidade mamográfica e classificação Breast Imaging Reporting and Data System), e sua relação com a estimativa de risco para câncer de mama (BCRE). Os dados clínicos de 3.665 mulheres (40-69 anos) participantes de um programa de rastreamento mamográfico no Brasil foram obtidos por revisão de prontuários. As BCRE foram calculadas utilizando modelo de Gail 2. A média da estimativa de risco em 5 anos foi de 1,0% (0,4-4,8%; desvio padrão, DP=0,4%) e ao longo da vida foi de 7,9% (2,6-39,0%, DP=2,6%). Em 6,7% da amostra, a BCRE foi ?1,67%. Quando avaliaram-se os fatores de risco não incluídos no modelo de Gail 2, observou-se associação entre aumento da densidade da mama e maior BCRE (p<0,001). As BCRE obtidas foram semelhantes às observadas em outros países. Nenhum dos fatores de risco para câncer de mama incluídos no modelo Gail 2 foram superestimados. A densidade mamográfica aumentada foi observada em mulheres com maior BCRE. A inclusão da densidade mamográfica no modelo de Gail 2 pode aumentar o seu desempenho.