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Dive into the research topics where Michael Gattas is active.

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Featured researches published by Michael Gattas.


Journal of Clinical Oncology | 2000

Intention to Undergo Prophylactic Bilateral Mastectomy in Women at Increased Risk of Developing Hereditary Breast Cancer

Bettina Meiser; Phyllis Butow; Michael Friedlander; Vivienne Schnieden; Michael Gattas; Judy Kirk; Graeme Suthers; Eric Haan; Katherine L. Tucker

PURPOSE To assess intention to undergo prophylactic bilateral mastectomy and psychologic determinants in unaffected women at increased risk of developing hereditary breast cancer. PATIENTS AND METHODS Three hundred thirty-three women who were awaiting their initial appointments for risk assessment, advice about surveillance, and prophylactic options at one of 14 familial cancer clinics participated in a cross-sectional, questionnaire-based survey. RESULTS Nineteen percent of women would consider and 47% would not consider a prophylactic mastectomy, should genetic testing identify a mutation in a breast cancer-predisposing gene, whereas 34% were unsure and 1% had already undergone a prophylactic mastectomy. In a bivariate analysis, women at a moderately increased risk of developing breast cancer had the highest proportion of subjects reporting that they would consider a prophylactic mastectomy (25%), compared with women at high risk (16%) (chi(2) = 7.79; P =.051). In multivariate analyses, consideration of prophylactic mastectomy strongly correlated with high levels of breast cancer anxiety (odds ratio [OR] = 17.4; 95% confidence interval [CI], 4.35 to 69.71; P =. 0001) and overestimation of ones breast cancer risk (OR = 3.01; 95% CI, 1.43 to 6.32; P =.0036), whereas there was no association with objective breast cancer risk (P =.60). CONCLUSION A significant proportion of women at increased risk of developing hereditary breast cancer would consider prophylactic mastectomy. Although prophylactic mastectomy may be appropriate in women at high risk of developing breast cancer, it is perhaps less so in those who have a moderately increased risk. Such moderate-risk women are likely to benefit from interventions aimed at reducing breast cancer anxiety and correcting exaggerated breast cancer risk perceptions.


Patient Education and Counseling | 2001

Long-term outcomes of genetic counseling in women at increased risk of developing hereditary breast cancer

Bettina Meiser; Phyllis Butow; Alex Barratt; Vivienne Schnieden; Michael Gattas; Judy Kirk; Clara Gaff; Graeme Suthers; Katherine L. Tucker

This multicenter study evaluated the impact of genetic counseling in 218 women at risk of developing hereditary breast cancer. Women were assessed prior to counseling and 12-month post-counseling using self-administered, mailed questionnaires. Compared to baseline, breast cancer genetics knowledge was increased significantly at follow-up, and greater increases in knowledge were associated with educational level. Breast cancer anxiety decreased significantly from baseline to follow-up, and these decreases were associated with improvements in perceived risk. A significant decrease in clinical breast examination was observed at the 12-month follow-up. Findings suggest that women with a family history of breast cancer benefit from attending familial cancer clinics as it leads to increases in breast cancer genetics knowledge and decreases in breast cancer anxiety. The lowered rates of clinical breast examination indicate that the content of genetic counseling may need to be reviewed to ensure that women receive and take away the right message.


Clinical Cancer Research | 2008

Molecular, Pathologic, and Clinical Features of Early-Onset Endometrial Cancer: Identifying Presumptive Lynch Syndrome Patients

Michael D. Walsh; Margaret C. Cummings; Daniel D. Buchanan; Wendy M. Dambacher; Sven Arnold; Diane McKeone; Rebecca Byrnes; Melissa A. Barker; Barbara A. Leggett; Michael Gattas; Jeremy R. Jass; Amanda B. Spurdle; Joanne Young; Andreas Obermair

Purpose: A woman with early-onset endometrial cancer (EC) may represent the “sentinel” cancer event in a Lynch syndrome kindred. The aim of this study was to determine the incidence of Lynch syndrome in a series of young-onset EC, and to identify molecular, clinical, and pathologic features that may alert clinicians to the presence of this disorder. Experimental Design: Patients with EC, ages ≤50 years, were identified from the Queensland Centre for Gynaecological Cancer. Tumor sections underwent histopathology review and were immunostained for mismatch repair proteins. Tumor DNA was tested for microsatellite instability and methylation of MLH1. Patients were conservatively classified as presumptive Lynch syndrome if their tumors showed loss of at least one mismatch repair protein and were negative for methylation of MLH1. Personal and family history of cancer was reviewed where available. Results: Presumptive Lynch syndrome was seen in 26 of 146 (18%) tumors. These tumors were more likely to be poorly differentiated, International Federation of Gynecology and Obstetrics stage II and above, have tumor-infiltrating lymphocytes, have higher mitotic rate, and have deeper myometrial invasion (P < 0.05). Lynch syndrome cases were more likely to be associated with a positive family history when analyzed for Amsterdam criteria II, diagnosis of a Lynch syndrome spectrum cancer in at least one first-degree relative, and family history of any cancer (P < 0.05). Conclusion: Presumptive Lynch syndrome was identified in 18% of early-onset EC. A risk of this magnitude would argue for routine immunohistochemical testing of tumors in patients diagnosed with EC at or before the age of 50 years.


The American Journal of Gastroenterology | 2012

Cancer Risks for Relatives of Patients With Serrated Polyposis

Aung Ko Win; Rhiannon J. Walters; Daniel D. Buchanan; Mark A. Jenkins; Kevin Sweet; Wendy L. Frankel; Albert de la Chapelle; Diane McKeone; Michael D. Walsh; Mark Clendenning; Sally-Ann Pearson; Erika Pavluk; Belinda Nagler; John L. Hopper; Michael Gattas; Jack Goldblatt; Jill George; Graeme Suthers; Kerry Phillips; Sonja Woodall; Julie Arnold; Katherine L. Tucker; Michael Field; Sian Greening; Steve Gallinger; Melyssa Aronson; Renee Perrier; Michael O. Woods; Jane Green; Neal I. Walker

OBJECTIVES:Serrated polyposis (hyperplastic polyposis) is characterized by multiple polyps with serrated architecture in the colorectum. Although patients with serrated polyposis are known to be at increased risk of colorectal cancer (CRC) and possibly extracolonic cancers, cancer risk for their relatives has not been widely explored. The aim of this study was to estimate the risks of CRC and extracolonic cancers for relatives of patients with serrated polyposis.METHODS:A cohort of the 1,639 first- and second-degree relatives of 100 index patients with serrated polyposis recruited regardless of a family history of polyps or cancer from genetic clinics in Australia, New Zealand, Canada, and the USA, were retrospectively analyzed to estimate the country-, age-, and sex-specific standardized incidence ratios (SIRs) for relatives compared with the general population.RESULTS:A total of 102 CRCs were observed in first- and second-relatives (SIR 2.25, 95% confidence interval (CI) 1.75–2.93; P<0.001), with 54 in first-degree relatives (SIR 5.16, 95% CI 3.70–7.30; P<0.001) and 48 in second-degree relatives (SIR 1.38, 95% CI 1.01–1.91; P=0.04). Six pancreatic cancers were observed in first-degree relatives (SIR 3.64, 95% CI 1.70–9.21; P=0.003). There was no statistical evidence of increased risk for cancer of the stomach, brain, breast, or prostate.CONCLUSIONS:Our finding that relatives of serrated polyposis patients are at significantly increased risk of colorectal and pancreatic cancer adds to the accumulating evidence that serrated polyposis has an inherited component.


Clinical Cancer Research | 2010

Lynch Syndrome-Associated Breast Cancers: Clinicopathologic Characteristics of a Case Series from the Colon Cancer Family Registry

Michael D. Walsh; Daniel D. Buchanan; Margaret C. Cummings; Sally Pearson; Sven Arnold; Mark Clendenning; Rhiannon J. Walters; Diane McKeone; Amanda B. Spurdle; John L. Hopper; Mark A. Jenkins; Kerry Phillips; Graeme Suthers; Jill George; Jack Goldblatt; Amanda Muir; Katherine L. Tucker; Elise S. Pelzer; Michael Gattas; Sonja Woodall; Susan Parry; Finlay Macrae; Robert W. Haile; John A. Baron; John D. Potter; Loic Le Marchand; Bharati Bapat; Stephen N. Thibodeau; Noralane M. Lindor; Michael A. McGuckin

Purpose: The recognition of breast cancer as a spectrum tumor in Lynch syndrome remains controversial. The aim of this study was to explore features of breast cancers arising in Lynch syndrome families. Experimental Design: This observational study involved 107 cases of breast cancer identified from the Colorectal Cancer Family Registry (Colon CFR) from 90 families in which (a) both breast and colon cancer co-occurred, (b) families met either modified Amsterdam criteria, or had at least one early-onset (<50 years) colorectal cancer, and (c) breast tissue was available within the biospecimen repository for mismatch repair (MMR) testing. Eligibility criteria for enrollment in the Colon CFR are available online. Breast cancers were reviewed by one pathologist. Tumor sections were stained for MLH1, PMS2, MSH2, and MSH6, and underwent microsatellite instability testing. Results: Breast cancer arose in 35 mutation carriers, and of these, 18 (51%) showed immunohistochemical absence of MMR protein corresponding to the MMR gene mutation segregating the family. MMR-deficient breast cancers were more likely to be poorly differentiated (P = 0.005) with a high mitotic index (P = 0.002), steroid hormone receptor–negative (estrogen receptor, P = 0.031; progesterone receptor, P = 0.022), and to have peritumoral lymphocytes (P = 0.015), confluent necrosis (P = 0.002), and growth in solid sheets (P < 0.001) similar to their colorectal counterparts. No difference in age of onset was noted between the MMR-deficient and MMR-intact groups. Conclusions: MMR deficiency was identified in 51% of breast cancers arising in known mutation carriers. Breast cancer therefore may represent a valid tissue option for the detection of MMR deficiency in which spectrum tumors are lacking. Clin Cancer Res; 16(7); 2214–24. ©2010 AACR.


American Journal of Medical Genetics | 2000

Clinical findings in a patient with FGFR1 P252R mutation and comparison with the literature.

Tony Roscioli; S. Flanagan; P. Kumar; John Masel; Michael Gattas; V. Hyland; I.A. Glass

We report on a patient with the skeletal findings of Jackson-Weiss syndrome, who manifests only mild craniofacial anomalies. Molecular analysis of her fibroblast growth factor receptor 1 gene (FGFR1) identified a heterozygous P252R missense mutation, previously only reported with FGFR1-Pfeiffer syndrome like manifestations. Mutations in the immunoglobulin-like, II-III (IgII-III) linker region of FGFR1 and FGFR3 molecules may present as a skeletal dysplasia affecting the appendicular skeleton including, brachydactyly, short broad middle phalanges, phalangeal epiphyseal coning and broad halluces. This communication is a further example of the phenomenon of an activated FGFR molecule resulting in overlapping manifestations in FGFR syndromes.


The American Journal of Surgical Pathology | 2013

Multiplicity and Molecular Heterogeneity of Colorectal Carcinomas in Individuals With Serrated Polyposis

Christophe Rosty; Michael D. Walsh; Rhiannon J. Walters; Mark Clendenning; Sally-Ann Pearson; Mark A. Jenkins; Aung Ko Win; John L. Hopper; Kevin Sweet; Wendy L. Frankel; Melyssa Aronson; Steve Gallinger; Jack Goldblatt; Katherine L. Tucker; Sian Greening; Michael Gattas; Sonja Woodall; Julie Arnold; Neal I. Walker; Susan Parry; Joanne Young; Daniel D. Buchanan

Serrated polyposis (SP) is a clinically defined syndrome characterized by the occurrence of multiple serrated polyps in the large intestine. Individuals with SP and their relatives are at increased risk of colorectal carcinoma (CRC). We aimed to determine the pathologic and molecular profiles of CRCs in individuals fulfilling World Health Organization criteria for SP. A total of 45 CRCs were obtained from 38 individuals with SP (27 female and 11 male patients; median age at CRC diagnosis, 58.5 y) attending genetics clinics. Tumor samples were pathologically reviewed, screened for somatic BRAF and KRAS mutations, and analyzed immunohistochemically for mismatch repair protein (MMR) expression. Tumors were spread throughout the large intestine, with 64% located in the proximal colon. Mutations in BRAF and KRAS and immunohistochemical evidence of MMR deficiency were found in 46%, 5%, and 38%, respectively. Nearly half of CRCs were BRAF/KRAS wild type, and these were associated with distal location (63%) and MMR proficiency (84%). Overexpression of p53 and/or evidence of &bgr;-catenin activation were identified in 13 CRCs. Ten patients (26%) had synchronous or metachronous CRCs. In conclusion, the majority of CRCs arising in individuals with SP do not harbor molecular hallmarks of serrated pathway CRCs but show a diverse range of molecular profiles. The high proportion of multiple CRCs suggests that individuals with SP would benefit from frequent colonoscopic surveillance and from a consideration of a more extensive colectomy at the time of CRC diagnosis.


British Journal of Dermatology | 2010

Phenotypic variability associated with WNT10A nonsense mutations

M. van Geel; Michael Gattas; Y. Kesler; P. Tong; H. Yan; Kim Tran; Peter M. Steijlen; Dédée F. Murrell; M.A.M. van Steensel

elevated (IL-17A: clopidogrel, 237Æ8 pg mL; control, not detected; and IL-17F: clopidogrel, 187Æ3 pg mL; control, not detected). On the other hand, the serum IL-17A level was below the detection limit (< 60 pg mL), and the serum IL-17F level was elevated (clopidogrel, 265Æ0 pg mL; control, 120Æ2 pg mL). AGEP is a rare and severe skin eruption, of which 90% of cases are induced by drugs such as antibiotics, calcium channel blockers, carbamazepine, antimycotics, nonsteroidal antiinflammatory drugs and paracetamol, but clopidogrel has not previously been reported as a cause of AGEP. The mechanism of AGEP is not fully understood, but drugspecific CD4+ T cells have been considered to be involved in neutrophil-rich inflammatory responses and to orchestrate the immune reaction directly by the production of IL-8, a chemoattractant for neutrophils. On the other hand, it has also been hypothesized that AGEP might be induced indirectly via the production of IL-17, which that induces IL-8 production; however, this has not yet been proven. In this report, we have presented the first case of AGEP with a positive DLST for clopidogrel, and elevated IL-17A and IL-17F in the culture supernatant. Although it is limited to a single case, our study suggests that Th17 may be involved in the pathogenesis of AGEP.


Modern Pathology | 2013

Lynch syndrome-associated breast cancers do not overexpress chromosome 11-encoded mucins.

Michael D. Walsh; Margaret C. Cummings; Sally-Ann Pearson; Mark Clendenning; Rhiannon J. Walters; Belinda Nagler; John L. Hopper; Mark A. Jenkins; Graeme Suthers; Jack Goldblatt; Katherine L. Tucker; Michael Gattas; Julie Arnold; Susan Parry; Finlay Macrae; Michael A. McGuckin; Joanne Young; Daniel D. Buchanan

Mismatch repair-deficient breast cancers may be identified in Lynch syndrome mutation carriers, and have clinicopathological features in common with mismatch repair-deficient colorectal and endometrial cancers such as tumour-infiltrating lymphocytes and poor differentiation. Mismatch repair-deficient colorectal cancers frequently show mucinous differentiation associated with upregulation of chromosome 11 mucins. The aim of this study was to compare the protein expression of these mucins in mismatch repair-deficient and -proficient breast cancers. Cases of breast cancer (n=100) were identified from families where (1) both breast and colon cancer co-occurred and (2) families met either modified Amsterdam criteria or had at least one early-onset (<50 years) colorectal cancer. Tumour sections were stained for the epithelial mucins, MUC2, MUC5AC, MUC5B and MUC6, and the homeobox protein CDX2, a regulator of MUC2 expression. In all, 16 mismatch repair-deficient Lynch syndrome breast cancers and 84 non-Lynch breast cancers were assessed for altered mucin expression. No significant difference in the expression of MUC2, MUC5AC or MUC6 was observed between the mismatch repair-deficient and mismatch repair-proficient breast cancers; however, there was a trend for mismatch repair-deficient tumours to express high levels of MUC5B less frequently (P=0.07, OR=0.2 (0.0–1.0)). Co-expression of two or more gel-forming mucins was common. Ectopic expression of CDX2 was associated with expression of MUC2 (P=0.035, OR=8.7 (1.3–58.4)). Mismatch repair-deficient breast cancers do not show differential expression of the mucins genes on chromosome 11 when compared with mismatch repair-proficient breast cancers, in contrast with mismatch repair-deficient colorectal and endometrial cancers, which frequently have increased mucin protein expression when compared with their mismatch repair-proficient counterparts. In addition, ectopic CDX2 expression is positively associated with de novo MUC2 expression.


Genetics in Medicine | 2018

A craniosynostosis massively parallel sequencing panel study in 309 Australian and New Zealand patients: findings and recommendations

Eric Lee; Trang Le; Ying Zhu; George Elakis; Anne Turner; William Lo; Hanka Venselaar; Carol-Ann Verrenkamp; Nicole Snow; David Mowat; Edwin P. Kirk; Rani Sachdev; Janine Smith; Natasha J Brown; Mathew Wallis; Christopher Barnett; Fiona McKenzie; Mary-Louise Freckmann; Felicity Collins; Maya Chopra; Nerine Gregersen; Ian Hayes; Sulekha Rajagopalan; Tiong Yang Tan; Zornitza Stark; Ravi Savarirayan; Alison Yeung; Lesley C. Adès; Michael Gattas; Kate Gibson

PurposeThe craniosynostoses are characterized by premature fusion of one or more cranial sutures. The relative contribution of previously reported genes to craniosynostosis in large cohorts is unclear. Here we report on the use of a massively parallel sequencing panel in individuals with craniosynostosis without a prior molecular diagnosis.MethodsA 20-gene panel was designed based on the genes’ association with craniosynostosis, and clinically validated through retrospective testing of an Australian and New Zealand cohort of 233 individuals with craniosynostosis in whom previous testing had not identified a causative variant within FGFR1-3 hot-spot regions or the TWIST1 gene. An additional 76 individuals were tested prospectively.ResultsPathogenic or likely pathogenic variants in non-FGFR genes were identified in 43 individuals, with diagnostic yields of 14% and 15% in retrospective and prospective cohorts, respectively. Variants were identified most frequently in TCF12 (N = 22) and EFNB1 (N = 8), typically in individuals with nonsyndromic coronal craniosynostosis or TWIST1-negative clinically suspected Saethre–Chotzen syndrome. Clinically significant variants were also identified in ALX4, EFNA4, ERF, and FGF10.ConclusionThese findings support the clinical utility of a massively parallel sequencing panel for craniosynostosis. TCF12 and EFNB1 should be included in genetic testing for nonsyndromic coronal craniosynostosis or clinically suspected Saethre–Chotzen syndrome.

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Katherine L. Tucker

University of Massachusetts Lowell

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Michael D. Walsh

QIMR Berghofer Medical Research Institute

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Jack Goldblatt

University of Western Australia

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Rhiannon J. Walters

QIMR Berghofer Medical Research Institute

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Diane McKeone

QIMR Berghofer Medical Research Institute

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