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  • 1
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2013
    In:  Journal of Clinical Oncology Vol. 31, No. 15_suppl ( 2013-05-20), p. e12546-e12546
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 15_suppl ( 2013-05-20), p. e12546-e12546
    Abstract: e12546 Background: The clinical diagnosis of Lynch syndrome is usually established when a family fulfills the Amsterdam Criteria, and confirmed by identification of MMR deficiency and/or germline mutations in one of the MMR genes. In a subset of families with Amsterdam criteria, no evidence of DNA mismatch repair deficiency can be identified and this clinical entity has been designated “Familial Colorectal Cancer Type X (FCCTX)”. Methods: The prevalence of MMR deficiency was assessed in a group of 25 individuals with colorectal or endometrial cancer from 20 families fulfilling Amsterdam criteria in Southern Brazil. MMR deficiency was assessed by IHC testing using a panel of antibodies against MSH2, MLH1, MSH6, and PMS2. In cases showing loss of nuclear expression of MLH1, presence of the BRAF p.V600E mutation and microsatellite instability were assessed in the tumor. Results: Fourteen of the 20 families studied fulfilled Amsterdam II criteria. MMR deficiency was identified in the tumor of 11 index cases and in the remaining 9, nuclear expression of all four MMR proteins was normal, suggesting the diagnosis of FCCTX. This FCCTX phenotype was observed in both Amsterdam I and Amsterdam II families. CRC with MMR-deficiency was diagnosed at an earlier age (41.2 years) than CRC showing MMR proficiency (47.2 years), although the difference did not reach significance. Conclusions: FCCTX is a frequent differential diagnosis in hereditary colorectal cancer in patients presenting to high risk cancer genetics clinics in Southern Brazil and further molecular characterization of hereditary colorectal cancer families with these features is warranted.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2013
    detail.hit.zdb_id: 2005181-5
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  • 2
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2007
    In:  Journal of Clinical Oncology Vol. 25, No. 7 ( 2007-03-01), p. 913-914
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 25, No. 7 ( 2007-03-01), p. 913-914
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2007
    detail.hit.zdb_id: 2005181-5
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  • 3
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. 1522-1522
    Abstract: 1522 Background: The exact contribution of TP53 germline mutations, associated with Li Fraumeni Syndrome, to the overall burden of cancer is still only partially known. Studies in Southern and Southeastern Brazil have shown that a specific germline mutation at codon 337 (c.1010G 〉 A; p.R337H), has incomplete penetrance and may be present in a significant number of subjects (estimated frequency at the populational level of 1:300 individuals). In an exploratory approach, the aim of the study is to assess the frequency of the p.R337H mutation in women from different Brazilian regions, diagnosed with breast cancer (BC) before 46 and after 55 years of age, and unselected for family history of cancer. Methods: Formalin-fixed paraffin-embedded (FFPE) non-tumoral tissue (lymph nodes or normal breast) of women diagnosed with BC between 2000 and 2010 in 3 pathology laboratories from the Brazilian cities of Porto Alegre, São Paulo and Barretos were obtained retrospectively and analyzed after anonimization. Genomic DNA was isolated with standard methods and genotyping performed in duplicates by qPCR (TaqMan assay). Confirmation of all mutation-positive and a sample of mutation-negative cases were done by TP53 exon 10 sequencing or by a second independent qPCR analysis. Results: Analysis of 515 BC-affected women identified the p.R337H mutation in the germline of 70 (8,6%) cases: 49/403 (12,1%) diagnosed before 46 years and 21/412 (5,1%) diagnosed after 55 years. BC occurred earlier in p.R337H mutation carriers than in non-carriers (p=0.001). Conclusions: Preliminary analysis in a sample of women with BC indicates that p.R337H founder mutation is present in a high proportion of cases, especially those diagnosed at a young age. Regional genetic background and recruitment strategies may account for the different mutation frequencies observed in the centers of study. The occurrence of this mutation at such a high frequency in a particular geographic region has important implications for disease management and cancer risk counseling for these patients and families. This mutation likely contributes to a significant proportion of the health burden associated with BC in Brazil. Financial support: FIPE-HCPA, CAPES, FAPERGS and Glaxo Smith Kline.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2012
    detail.hit.zdb_id: 2005181-5
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  • 4
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. e13546-e13546
    Abstract: e13546 Background: Inactivating TP53 mutations are common events in different types of cancers, including pancreatic adenocarcinoma, where it occurs in as much as 70% of cases. Accumulation of mutant p53 provides a molecular target that may be reactivated into a conformation capable of arresting tumor growth. The small molecule PRIMA-1 (p53 reactivation and induction of massive apoptosis) has been shown to selectively induce apoptosis in tumor cells by reactivating some p53 mutants, but no previous studies have investigated its effects in pancreatic cancer. Methods: PANC-1 (mutant TP53 R273H) and CAPAN-2 (wild-type TP53) pancreatic cell lines were used as in vitro models. We tested the effects of PRIMA-1 on cell viability (MTT assay), apoptosis (morphology, AnnexinV/FITC-FACS), cell cycle (BrdU incorporation) and expression of p53 regulated proteins by western blotting. As control of p53-dependent effects, PANC-1 cell lines were transfected with siRNA against TP53 (sip53). Results: PRIMA-1 selectively induced apoptosis in PANC-1 cells compared to CAPAN-2 cells and this effect was concomitant with an increase in the levels of MDM2, Bax and cleaved caspase-3 as detected by western blot analysis. Treatment with PRIMA-1 for 24h induced a 50% reduction in DNA synthesis whereas G2/M arrest was detected after 12h of treatment. p53 silencing in PANC-1 decreased the cytotoxicity of PRIMA-1, characterizing a p53-dependent effect. Finally, N-acetylcysteine completely blocked PRIMA-1-induced growth suppression and apoptosis, suggesting that PRIMA-1 exerts its effect at least in part via restoring redox-dependent effects to mutant p53. Conclusions: Our data indicate that PRIMA-1 induces apoptosis in TP53 mutant pancreatic cancer cells by promoting the re-activation of p53 and subsequent of proapoptotic signaling pathways, suggesting a possible mechanism for effective targeting of pancreatic cancer.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2012
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  • 5
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2014
    In:  Journal of Clinical Oncology Vol. 32, No. 15_suppl ( 2014-05-20), p. e22111-e22111
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 32, No. 15_suppl ( 2014-05-20), p. e22111-e22111
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2014
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  • 6
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 31, No. 15_suppl ( 2013-05-20), p. e22154-e22154
    Abstract: e22154 Background: Recent studies in North American and British series have suggested an association between germline TP53 mutations and early onset HER2-positive breast cancer (BC). Mutations in the TP53 gene are estimated to occur in 1:2,000-1:5,000 individuals of the general population. Among women with BC who are unselected for family history they occur in up to 0.25%. In women with early-onset BC ( 〈 30 years) they occur in up to 7%. A specific germline TP53 mutation (c.1010G 〉 A; p.R337H) has been encountered in 0.3% of the general population, in 13.3% of Li-Fraumeni-like families and in 0.5-2.4% of BC-affected women in Brazil. In an exploratory approach, the aim of this study was to investigate, in our series, if there is an association between human epidermal growth factor receptor 2 (HER2) amplification and the germline TP53 p.R337H mutation in a series of BC-affected women. Methods: A series of 718 Brazilian BC-affected women was genotyped in our previous study and 64 (8.9%) were mutation carriers. These cases were recruited from 3 centers and HER2 analysis was performed by immunohistochemistry (IHC) in each center according to validated protocols. Statistical analysis was done using SPSS software. Results: In 47 of 64 mutation carriers (73.5%), BC showed HER expression (either 1+, 2+ or 3+) while among 654 non-carriers, this immunophenotype was observed in 320 (48.9%) (p 〈 0.001). This pattern was still observed after stratification of groups according to age at diagnosis (≤45 and ≥55 years) (p 〈 0.001 and 0.03, respectively) and was independent of recruiting center. Conclusions: These results indicate that BC developing on a background of the founder Brazilian TP53 p.R337H mutation shows more frequently some amplification of HER2, consistent with recent studies showing an association between germline TP53 mutations and BC with HER2 hyperexpression. These findings should be confirmed in larger series to understand the significance of the association. If confirmed, this finding may justify germline TP53 p.R337H mutation testing in all HER2-positive Brazilian BC patients and would have a significant impact on patient and family counseling as well as on treatment.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
    RVK:
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2013
    detail.hit.zdb_id: 2005181-5
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  • 7
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2012
    In:  Journal of Clinical Oncology Vol. 30, No. 15_suppl ( 2012-05-20), p. e21042-e21042
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. e21042-e21042
    Abstract: e21042 Background: Germline mutations in the TP53 gene are the underlying genetic defect of Li-Fraumeni Syndrome (LFS) and its variant, Li-Fraumeni-like (LFL) Syndrome, autosomal dominant disorders characterized by predisposition to multiple early-onset cancers. More recently, p53 is emerging as an important player in redox metabolism and important enzymes involved in defenses against oxidative stress have shown to be regulated by p53, including glutathione peroxidase 1 (GPX1) and mitochondrial superoxide dismutase 2 (SOD2). The aim of the present study was to investigate the redox profile parameters in blood of p.R337H mutation carriers and non-carriers individuals. Methods: A total of 34 individuals were included in the study and they were divided in two groups: mutation carriers (n=17) and non-carriers (n=17). Antioxidant enzyme activities (SOD, CAT, GPx) and oxidative stress parameters (Protein carbonyl content, Sulfhydryl content and TBARS) were measured in plasma, erythrocytes, leukocytes and serum. Results: Erythrocyte SOD and GPx activities, two first-line players in enzimatic antioxidant defense, differed significantly between mutation carriers and non-carriers, with an increased activity in the latter (p 〉 0,05). Plasma Carbonyl content, an indicative of protein damage related to ROS overgeneration, was also increased in carriers (p=0,015). There was no significant difference between groups in all other parameters evaluated. Conclusions: Our findings suggest that TP53 p.R337H mutation carriers present different antioxidant enzyme activities and oxidative stress parameters when compared to non-carriers.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    RVK:
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2012
    detail.hit.zdb_id: 2005181-5
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  • 8
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2017
    In:  Journal of Clinical Oncology Vol. 35, No. 15_suppl ( 2017-05-20), p. e13009-e13009
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 15_suppl ( 2017-05-20), p. e13009-e13009
    Abstract: e13009 Background: Recent advances in genetics and molecular biology have made possible to define the hereditary risk of certain diseases. About 10% of cancer are due to a hereditary syndrome and increasing access to genetic testing allows us to identify people or families at risk. Methods: A multidisciplinary team composed of clinical oncologists and geneticists retrospectively evaluated all cancer patients referred to the outpatient clinics of the Hospital de Clínicas de Porto Alegre Cancer Center between October 1 st , 2014 and July 31 st , 2015. Epidemiological data, pathological examination and family history of cancer recorded in the electronic database at the first visit to the oncologist were analyzed. Results: A total of 708 patients were analyzed. 44 (6.21%) patients were identified and referred for genetic evaluation by the clinical oncologist. Another 85 (12.0%) patients were identified by the multidisciplinary team, completing a total of 129 (18.22%), patients that should be evaluated to the presence of a hereditary syndrome. 164 (23.16%) patients could not be evaluated by the multidisciplinary team because insufficient data were recorded especially those related to family history of cancer. The main diagnosis that indicated genetic evaluation were colorectal cancer (47 cases - 36.43%), breast cancer (36 cases - 27.90%) and ovarian cancer (8 cases - 6.20%). Conclusions: A multidisciplinary evaluation of the oncologic patient is mandatory. Few patients are referred to a genetic counseling and 1 out of 4 patient could not be evaluated because there was missing data in the medical records. A precise genetic evaluation can identify patient / families at risk to develop cancer, allowing the development of cancer prevention strategies in this high-risk population.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2017
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  • 9
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO)
    Abstract: The genomic underpinnings of inherited lung cancer risk are poorly understood. This prospective study characterized the clinical phenotype of patients and families with germline EGFR pathogenic variants (PVs). METHODS The INHERIT study (NCT01754025) enrolled lung cancer patients whose tumor profiling harbored possible germline EGFR PVs and their relatives, either in-person or remotely, providing germline testing and follow-up. RESULTS 141 participants were enrolled over a 5-year period, 100 (71%) remotely. Based upon prior genotyping, 116 participants from 59 kindreds were tested for EGFR T790M, consistent with a pattern of Mendelian inheritance with variable lung cancer penetrance. In confirmed or obligate carriers of a germline EGFR PV from 39 different kindreds, 50/91 (55%) were affected with lung cancer with 34/65 (52%) diagnosed by age 60. Somatic testing of lung cancers in carriers revealed that 35 of 37 (95%) had an EGFR driver co-mutation. Among 36 germline carriers without a cancer diagnosis, 15 had CT imaging and 9 had lung nodules, including a 28-year-old with 〉 10 lung nodules. Given geographic enrichment of germline EGFR T790M in the Southeast United States, genome-wide haplotyping of 46 germline carriers was performed and identified a 4.1 Mb haplotype shared by 41 (89%), estimated to originate 223-279 years ago. CONCLUSIONS In this first prospective description of familial EGFR-mutant lung cancer, we identify a recent founder germline EGFR T790M variant enriched in the US Southeast. The high prevalence of EGFR-driver lung adenocarcinomas and lung nodules in germline carriers supports effort to identify affected patients and family members for investigation of CT-based screening for these high-risk individuals.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2023
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  • 10
    In: JCO Global Oncology, American Society of Clinical Oncology (ASCO), , No. 8 ( 2022-07)
    Abstract: To report on pathogenic germline variants detected among individuals undergoing genetic testing for hereditary breast and/or ovarian cancer (HBOC) from Latin America and compare them with self-reported Hispanic individuals from the United States. METHODS In this cross-sectional study, unrelated individuals with a personal/family history suggestive of HBOC who received clinician-ordered germline multigene sequencing were grouped according to the location of the ordering physician: group A, Mexico, Central America, and the Caribbean; group B, South America; and group C, United States with individuals who self-reported Hispanic ethnicity. Relatives who underwent cascade testing were analyzed separately. RESULTS Among 24,075 unrelated probands across all regions, most were female (94.9%) and reported a personal history suggestive of HBOC (range, 65.0%-80.6%); the mean age at testing was 49.1 ± 13.1 years. The average number of genes analyzed per patient was highest in group A (A 63 ± 28, B 56 ± 29, and C 40 ± 28). Between 9.1% and 18.7% of patients had pathogenic germline variants in HBOC genes (highest yield in group A), with the majority associated with high HBOC risk. Compared with US Hispanics individuals the overall yield was significantly higher in both Latin American regions (A v C P = 1.64×10 –9 , B v C P 〈 2.2×10 –16 ). Rates of variants of uncertain significance were similar across all three regions (33.7%-42.6%). Cascade testing uptake was low in all regions (A 6.6%, B 4.5%, and C 1.9%). CONCLUSION This study highlights the importance of multigene panel testing in Latin American individuals with newly diagnosed or history of HBOC, who can benefit from medical management changes including targeted therapies, eligibility to clinical trials, risk-reducing surgeries, surveillance and prevention of secondary malignancy, and genetic counseling and subsequent cascade testing of at-risk relatives.
    Type of Medium: Online Resource
    ISSN: 2687-8941
    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2022
    detail.hit.zdb_id: 3018917-2
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