C Blake Gilks

Vancouver General Hospital, Vancouver, British Columbia, Canada

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Publications (234)1231.36 Total impact

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    ABSTRACT: Vulvar acanthosis with altered differentiation is an uncommon proliferation of the vulvar squamous epithelium that is typically seen in association with verrucous carcinoma, and may represent an early phase of non-HPV-related squamous neoplastic transformation. We report a case of vulvar acanthosis with altered differentiation that, over a 5-yr period, progressed first to verrucous carcinoma in association with well-differentiated invasive squamous cell carcinoma and then, after treatment with radiotherapy, to poorly differentiated carcinoma with a component of anaplastic carcinoma. This case supports the concept of vulvar acanthosis with altered differentiation as a premalignant lesion, with potential to progress to invasive carcinoma. (C)2015International Society of Gynecological Pathologists
    International Journal of Gynecological Pathology 07/2015; 34(4). DOI:10.1097/PGP.0000000000000182 · 1.63 Impact Factor
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    ABSTRACT: A comprehensive pathological report is essential for optimal patient management, cancer staging and prognostication. In many countries, proforma reports are used but these vary in their content. The International Collaboration on Cancer Reporting (ICCR) is an alliance formed by the Royal College of Pathologists of Australasia, the Royal College of Pathologists of the United Kingdom, the College of American Pathologists, the Canadian Partnership Against Cancer and the European Society of Pathology, with the aim of developing an evidence-based reporting data set for each cancer site. This will reduce the global burden of cancer data set development and reduplication of effort by different international institutions that commission, publish and maintain standardised cancer reporting data sets. The resultant standardisation of cancer reporting will benefit not only those countries directly involved in the collaboration but also others not in a position to develop their own data sets. We describe the development of a cancer data set by the ICCR expert panel for the reporting of primary ovarian, fallopian tube and peritoneal carcinoma and present the 'required' and 'recommended' elements to be included in the report with an explanatory commentary. This data set encompasses the recent International Federation of Obstetricians and Gynaecologists staging system for these neoplasms and the updated World Health Organisation Classification of Tumours of the Female Reproductive Organs. The data set also addresses issues about site assignment of the primary tumour in high-grade serous carcinomas and proposes a scoring system for the assessment of tumour response to neoadjuvant chemotherapy. The widespread implementation of this data set will facilitate consistent and accurate data collection, comparison of epidemiological and pathological parameters between different populations, facilitate research and hopefully will result in improved patient management.Modern Pathology advance online publication, 19 June 2015; doi:10.1038/modpathol.2015.77.
    Modern Pathology 06/2015; DOI:10.1038/modpathol.2015.77 · 6.36 Impact Factor
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    ABSTRACT: Epithelial ovarian cancer (EOC) consists of 5 major histotypes: high-grade serous carcinoma (HGSC), endometrioid carcinoma (EC), clear cell carcinoma (CCC), mucinous carcinoma (MC), and low-grade serous carcinoma (LGSC). Each can have a broad spectrum of morphologic appearances, and 1 histotype can closely mimic histopathologic features more typical of another. Historically, there has been a relatively high frequency of mixed, defined by 2 or more distinct histotypes present on the basis of routine histopathologic assessment, histotype carcinoma diagnoses (3% to 11%); however, recent immunohistochemical (IHC) studies identifying histotype-specific markers and allowing more refined histotype diagnoses suggest a much lower incidence. We reviewed hematoxylin and eosin-stained slides from 871 cases of EOC and found the frequency of mixed carcinomas to be 1.7% when modern diagnostic criteria are applied. Through international collaboration, we established a cohort totaling 22 mixed EOCs, consisting of 9 EC/CCC, 4 EC/LGSC, 3 HGSC/CCC, 2 CCC/MC, and 4 other combinations. We interrogated the molecular differences between the different components of each case using IHC, gene expression, and hotspot sequencing analyses. IHC data alone suggested that 9 of the 22 cases were not mixed tumors, as they presented a uniform immuno-phenotype throughout, and these cases most probably represent morphologic mimicry and variation within tumors of a single histotype. Synthesis of molecular data further reduces the incidence of mixed carcinomas. On the basis of these results, true mixed carcinomas with both morphologic and molecular support for the presence of >1 histotype within a given tumor represent <1% of EOCs.
    The American journal of surgical pathology 05/2015; DOI:10.1097/PAS.0000000000000476 · 4.59 Impact Factor
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    ABSTRACT: Hematogenous metastases are rarely present at diagnosis of ovarian clear cell carcinoma (OCC). Instead dissemination of these tumors is characteristically via direct extension of the primary tumor into nearby organs and the spread of exfoliated tumor cells throughout the peritoneum, initially via the peritoneal fluid, and later via ascites that accumulates as a result of disruption of the lymphatic system. The molecular mechanisms orchestrating these processes are uncertain. In particular, the signaling pathways used by malignant cells to survive the stresses of anchorage-free growth in peritoneal fluid and ascites, and to colonize remote sites, are poorly defined. We demonstrate that the transmembrane glycoprotein CUB-domain-containing protein 1 (CDCP1) has important and inhibitable roles in these processes. In vitro assays indicate that CDCP1 mediates formation and survival of OCC spheroids, as well as cell migration and chemoresistance. Disruption of CDCP1 via silencing and antibody-mediated inhibition markedly reduce the ability of TOV21G OCC cells to form intraperitoneal tumors and induce accumulation of ascites in mice. Mechanistically our data suggest that CDCP1 effects are mediated via a novel mechanism of protein kinase B (Akt) activation. Immunohistochemical analysis also suggested that CDCP1 is functionally important in OCC, with its expression elevated in 90% of 198 OCC tumors and increased CDCP1 expression correlating with poor patient disease-free and overall survival. This analysis also showed that CDCP1 is largely restricted to the surface of malignant cells where it is accessible to therapeutic antibodies. Importantly, antibody-mediated blockade of CDCP1 in vivo significantly increased the anti-tumor efficacy of carboplatin, the chemotherapy most commonly used to treat OCC. In summary, our data indicate that CDCP1 is important in the progression of OCC and that targeting pathways mediated by this protein may be useful for the management of OCC, potentially in combination with chemotherapies and agents targeting the Akt pathway.Oncogene advance online publication, 20 April 2015; doi:10.1038/onc.2015.101.
    Oncogene 04/2015; DOI:10.1038/onc.2015.101 · 8.56 Impact Factor
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    ABSTRACT: Endometrial cancer (EC) is the most common gynecologic malignancy with known risk factors including excess estrogen and hereditary syndromes. The objective of this study was to determine the proportion of young women with EC that could be attributed to these factors and if, as we suspected, there is a third population of young women in which neither factor is identifiable. We were interested in comparing clinicopathologic characteristics and outcomes across subgroups in order to better inform treatment recommendations. We performed a retrospective chart review of women age 15-49 diagnosed with EC or complex atypical hyperplasia. Demographic, clinicopathologic, treatment, fertility, and outcome parameters were analyzed. Of 719 women identified, 327 were fully evaluable. 57.5% fit the "High Estrogen" risk criteria. 8.25% met criteria for suspected Lynch syndrome. 34.25% classified as "Neither" had no classical risk factors identified. There were no statistical differences in age, gravidity, tumor grade, treatment selection and response to hormonal therapy. Age of menarche, stage, histology, and synchronous ovarian cancer differed significantly. Prevalence of synchronous ovarian cancer was 21.0% of "Neither", 23.1% of "Lynch", and 6.6% of "High Estrogen". For women who attempted pregnancy, 2/27 of "High Estrogen", 0/3 of "Lynch", and 2/16 of "Neither" achieved a live birth. This study confirmed that a third population of young women with EC exist that lack classical risk factors and have distinct clinicopathologic parameters. No difference in success of conservative treatment or live births was noted in the small cohort in whom this treatment approach was attempted. Copyright © 2015. Published by Elsevier Inc.
    Gynecologic Oncology 04/2015; DOI:10.1016/j.ygyno.2015.02.028 · 3.69 Impact Factor
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    ABSTRACT: •Conventional definitions of STIC do not capture all lesions associated with serous neoplasia and the presence of abnormal p53 expression may be helpful diagnostically.•The management of STICs and tubal atypias remain uncertain.•The POINT Project is a registry set up to address this critical gap in knowledge.
    03/2015; 35. DOI:10.1016/j.gore.2015.03.007
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    ABSTRACT: A proportion of endometrial carcinomas (ECs) are associated with deficient DNA mismatch repair (MMR). These tumors are characterized by high levels of microsatellite instability (MSI). Identification of MSI is important in identifying women who should be tested for Lynch syndrome and identifying a phenotype that may have specific prognostic and predictive implications. Genomic characterization of ECs has shown that MSI tumors form a distinct subgroup. The two most common methodologies for MSI assessment have not been compared in EC.
    Gynecologic Oncology 01/2015; 137(2). DOI:10.1016/j.ygyno.2015.01.541 · 3.69 Impact Factor
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    ABSTRACT: AimsEvidence indicates that most non-uterine high-grade serous carcinomas (HGSC) arise from the fallopian tube, but approaches to primary site assignment have not evolved to reflect this. This study aimed to assess application of recently proposed criteria for site assignment.Methods and Results151 HGSCs from four centres were reviewed retrospectively. 63/80 (79%) chemo-naïve (CN) and 45/71 (68%) post-neoadjuvant chemotherapy (NACT) cases were assigned as fallopian tube (FT) primaries with the new criteria, while 58/80 (73%) and 45/71 (63%) were considered ovarian primaries using traditional criteria (p<0.0001). In 111 prospectively collected HGSC's, with consistent detailed fimbrial examination, 44/53 (83%) CN and 44/58 (76%) NACT cases were assigned as FT primaries. Reproducibility of site assignment was tested in a subset of 50 cases: 4/4 reviewing pathologists agreed on primary site in 48/50 (96%), and 3/4 in 49/50 (98%) cases. Of the 53 prospectively studied CN cases, bilateral ovarian involvement (62%) was significantly more frequent than bilateral tubal involvement (12%, p<0.0001), further supporting tubal origin and ovarian metastasis in most cases.Conclusions With currently accepted protocols, the proposed guidelines are easy to apply and result in consistent site assignment in non-uterine HGSC. Most cases of non-uterine HGSC were considered primary FT neoplasms.This article is protected by copyright. All rights reserved.
    Histopathology 01/2015; DOI:10.1111/his.12651 · 3.30 Impact Factor
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    ABSTRACT: Uterine tumors resembling ovarian sex cord tumors (UTROSCTs) are rare uterine neoplasms characterized by pure or predominant epithelial-like patterns that share morphologic, immunohistochemical, and ultrastructural features with ovarian sex cord tumors. FOXL2 immunoexpression has recently been found in sex cord stromal tumors of the ovary, including granulosa cell tumors, Sertoli-Leydig cell tumors, thecomas, and fibromas, but mutations have been identified mostly in adult granulosa cell tumors. In this study, we investigated FOXL2 mutation status and protein expression in UTROSCTs. Mutational analysis using a TaqMan real-time polymerase chain reaction-based allelic discrimination assay was performed on formalin-fixed, paraffin-embedded tissue from 15 UTROSCTs. FOXL2 mutation was absent in all tumors. FOXL2 immunoexpression was tested in all 15 tumors. Intensity of staining was scored as weak, moderate, or strong. Percentage of tumor cells with nuclear staining was recorded as follows: 0 (negative); 1+ (1% to 25%); 2+ (26% to 50%); 3+ (51% to 75%); and 4+ (76% to 100%). Nuclear expression of FOXL2 was present in 6 of 15 (40%) UTROSCTs. One tumor demonstrated strong 4+ staining. Moderate expression was seen in 3 cases, including 2 and 1 showing 2+ and 1+ staining, respectively. Weak expression was observed in 2 tumors demonstrating 3+ and 1+ staining. Although UTROSCTs show overlapping morphologic, immunohistochemical, and ultrastructural features with sex cord stromal tumors of the ovary, they do not harbor FOXL2 mutation despite focal immunoreactivity in a subset of these tumors.
    American Journal of Surgical Pathology 01/2015; 39(5). DOI:10.1097/PAS.0000000000000367 · 4.59 Impact Factor
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    ABSTRACT: To conduct a cost-effectiveness analysis of opportunistic salpingectomy (elective salpingectomy at hysterectomy or instead of tubal ligation). A Markov Monte Carlo simulation model estimated the costs and benefits of opportunistic salpingectomy in a hypothetical cohort of women undergoing hysterectomy for benign gynecologic conditions or surgical sterilization. The primary outcome measure was the incremental cost-effectiveness ratio. Effectiveness was measured in terms of life expectancy gain. Sensitivity analyses accounted for uncertainty around various parameters. Monte Carlo simulation estimated the number of ovarian cancer cases associated with each strategy in the Canadian population. Salpingectomy with hysterectomy was less costly ($11,044.32±$1.56) than hysterectomy alone ($11,206.52±$29.81) or with bilateral salpingo-oophorectomy ($12,626.84±$13.11) but more effective at 21.12±0.02 years compared with 21.10±0.03 and 20.94±0.03 years, representing average gains of 1 week and 2 months, respectively. For surgical sterilization, salpingectomy was more costly ($9,719.52±$3.74) than tubal ligation ($9,339.48±$26.74) but more effective at 22.45±0.02 years compared with 22.43±0.02 years (average gain of 1 week) with an incremental cost-effectiveness ratio of $27,278 per year of life gained. Our results were stable over a wide range of costs and risk estimates. Monte Carlo simulation predicted that salpingectomy would reduce ovarian cancer risk by 38.1% (95% confidence interval [CI] 36.5-41.3%) and 29.2% (95% CI 28.0-31.4%) compared with hysterectomy alone or tubal ligation, respectively. Salpingectomy with hysterectomy for benign conditions will reduce ovarian cancer risk at acceptable cost and is a cost-effective alternative to tubal ligation for sterilization. Opportunistic salpingectomy should be considered for all women undergoing these surgical procedures.
    Obstetrics and Gynecology 01/2015; 70(5). DOI:10.1097/AOG.0000000000000630 · 4.37 Impact Factor
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    ABSTRACT: Sprouty (SPRY) proteins are well-characterized factors that inhibit receptor tyrosine kinase signaling. Our Human Exonic Evidence-Based Oligonucleotide (HEEBO) microarray results showed that the mRNA levels of SPRY2, but not of SPRY1 or SPRY4, are down-regulated in high-grade serous ovarian carcinoma (HGSC) tissues and epithelial ovarian cancer (EOC) cell lines. Molecular inversion probe (MIP) copy number analysis showed the deletion of the SPRY2 locus in HGSC. Overexpression of SPRY2 reduced EGF-induced cell invasion by attenuating EGF-induced E-cadherin down-regulation. Moreover, a positive correlation between SPRY2 and E-cadherin protein levels was observed in HGSC tissues. This study reveals the loss of SPRY2 in HGSC and indicates an important tumor-suppressive role for SPRY2 in mediating the stimulatory effect of EGF on human EOC progression. Copyright © 2014. Published by Elsevier B.V.
    FEBS Letters 12/2014; 589(3). DOI:10.1016/j.febslet.2014.12.012 · 3.34 Impact Factor
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    ABSTRACT: Most nonuterine high-grade serous carcinomas (HGSCs) in women with hereditary breast and ovarian cancer syndrome, due to germline BRCA1/2 mutation, arise in the fimbria of the fallopian tube. However, the site of origin of sporadic HGSC, which is usually widely disseminated at presentation, is not well established. We sought to characterize cases of HGSC discovered incidentally in patients not known to be at high risk, in order to determine the site distribution and possible origin of sporadic HGSC. Incidental microscopic, non-mass-forming cases of serous tubal intraepithelial carcinoma or HGSC in salpingo-oophorectomy specimens in which the tubes and ovaries had been extensively examined were identified. No patients were known or suspected BRCA1/2 mutation carriers. Twenty-one cases were identified (mean age: 57 y). Surgery was for benign disease (n=15), uterine endometrioid adenocarcinoma or atypical hyperplasia (n=3), bladder carcinoma (n=1), or ovarian serous borderline tumor (n=2). In 16 of 21 cases, the lesion was confined to the fallopian tube (unilateral in 14 cases, bilateral in 2). There was serous tubal intraepithelial carcinoma in all cases and invasive HGSC into the underlying lamina propria in 8 of these 16 cases; the invasive focus measured 1.3 cm or less in every case. In the remaining 5 cases, there was fallopian tube mucosal and ovarian involvement; in 2 of these cases, there was also microscopic peritoneal involvement. Sporadic cases of nonuterine HGSC arise in the fallopian tube fimbria in a large majority of cases, providing further evidence for the tubal origin of these neoplasms.
    American Journal of Surgical Pathology 12/2014; DOI:10.1097/PAS.0000000000000353 · 4.59 Impact Factor
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    ABSTRACT: Therapies that target overexpression of human epidermal growth factor receptor 2 (HER2) rely on accurate and timely assessment of all patients with new diagnoses. This study examines HER2 testing of primary breast cancer tissue when performed with immunohistochemistry (IHC) and additional in situ hybridization (ISH) for negative cases (IHC 0/1+). The analysis focuses on the rate of false-negative HER2 tests, defined as IHC 0/1+ with an ISH ratio ≥ 2.0, in eight pathology centers across Canada.
    Journal of Clinical Oncology 11/2014; 32(35). DOI:10.1200/JCO.2014.55.6092 · 17.88 Impact Factor
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    ABSTRACT: Context .- Immunohistochemical (IHC) testing for HER2/neu is becoming the standard of care for guiding adjuvant treatment of gastric carcinoma with trastuzumab. Objective .- To assess interlaboratory variation in IHC staining and interpretation across multiple laboratories. Design .- A tissue microarray consisting of 45 cores from 28 gastric cancers was distributed to 37 laboratories for HER2/neu assessment. The IHC results were compared against expert scores at an academic institution and correlated with in situ hybridization results from the originating specimen. Interlaboratory agreement was calculated using Cohen κ statistic. Results .- The survey demonstrated several variations in IHC methods, including the primary antibodies in use. There was excellent agreement among laboratories in HER2/neu(+) (IHC 3(+)) cases (κ = 0.80 ± 0.01) and very good agreement among laboratories in HER2/neu(-) (IHC 0 or 1(+)) cases (κ = 0.58 ± 0.01). Less agreement was observed among laboratories when scoring equivocal (IHC 2(+)) cases (κ = 0.22 ± 0.01). Sensitivity and specificity of HER2/neu IHC were 99% and 100%, respectively, when measured against expert review and consensus score as a reference standard. Conclusions .- There is substantial interlaboratory agreement in the interpretation of HER2/neu IHC despite variability in protocols. Although HER2/neu IHC is a highly sensitive and specific test, primary antibody selection may significantly affect IHC results. Furthermore, gastric tumors require a unique scoring system and expertise in interpretation. Intratumoral heterogeneity has a significant effect on HER2/neu scoring by IHC. Ongoing quality assurance exercises among laboratories will help ensure optimized HER2/neu testing.
    Archives of pathology & laboratory medicine 11/2014; 138(11):1495-502. DOI:10.5858/arpa.2013-0604-OA · 2.88 Impact Factor
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    ABSTRACT: Objectives: Formalin-fixed, paraffin-embedded unstained archived diagnostic tissue sections are frequently exchanged between clinical laboratories for iminunohistochemical staining. The manner in which such sections are prepared represents a type of preanalytical variable that must be taken into account given the growing importance of immunohistochemical assays, especially predictive and prognostic tests, in personalized medicine. Methods: Recommendatio. ns were derived from review of the literature and expert consensus of the Canadian Association of Pathologists Association canadienne des pathologists National Standards Committee for High Complexity Testing/ Immunohistochemistry. Results: Relevant considerations include the type of glass slide on which to mount the unstained sections; the thickness of the tissue sections; the time from slide preparation to testing; the environment, particularly the temperature at which the unstained sections will be maintained prior to testing; the inclusion of on-slide positive control tissue where possible; and whether patient identifier(s) should be included on slide labels. Conclusions: Clear communication between requesting and releasing laboratories will facilitate the proper preparation of unstained sections and also ensure that applicable privacy considerations are addressed
    American Journal of Clinical Pathology 11/2014; 142(5):629-33. DOI:10.1309/AJCP77GXYVEQXMXT · 3.01 Impact Factor
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    ABSTRACT: The contemporary oncologic pathology report conveys diagnostic, prognostic, predictive, and hereditary predisposition information. Each component may be premised on a morphologic feature or a biomarker. Clinical validity and reproducibility are paramount as is standardization of reporting and clinical response to ensure individualization of patient care. Regarding hereditary predisposition, morphology-based genetic referral systems in some instances have eclipsed genealogy-based systems, for example, cell type in ovarian cancer and BRCA screening. In other instances such as Lynch syndrome, morphology-based schemas supplement clinical schemas and there is an emerging standard of care for reflex biomarker testing. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome predisposes patients to uterine and cutaneous leiomyomas (LMs) and renal cell carcinomas (RCCs). Several authors have emphasized the role pathologists may play in identifying this syndrome by recognizing the morphologic characteristics of syndromic uterine LMs and RCCs. Recently immunohistochemical overexpression of S-(2-succinyl) cysteine (2SC) has been demonstrated as a robust biomarker of mutation status in tumors from HLRCC patients. In this blinded control-cohort study we demonstrate that the proposed morphologic criteria used to identify uterine LMs in HLRCC syndrome are largely irreproducible among pathologists and lack sufficient robustness to serve as a trigger to triage cases for 2SC immunohistochemistry or patients for further family/personal history inquiry. Although refinement of morphologic criteria can be considered, in view of the availability of a clinically robust biomarker, consideration should be given to reflex testing of uterine LMs with an appropriate age cut off or in the setting of a suspicious family history.
    International Journal of Gynecological Pathology 09/2014; 33(6). DOI:10.1097/PGP.0000000000000091 · 1.63 Impact Factor
  • Geburtshilfe und Frauenheilkunde 09/2014; 74(S 01). DOI:10.1055/s-0034-1388327 · 0.96 Impact Factor
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    ABSTRACT: Uterine sarcomas and carcinosarcomas are an aggressive group of uterine malignancies. The frequency of mismatch repair (MMR) protein loss by immunohistochemical evaluation has not been comprehensively characterized in this group of tumors; hence, the appropriateness of applying an immunohistochemical panel to screen for Lynch syndrome in these tumors remains unclear. We examined for the immunohistochemical loss of 4 MMR proteins (MLH1, MSH2, MSH6, and PMS2) in a series of 67 uterine carcinosarcomas and 51 uterine sarcomas (20 leiomyosarcomas, 11 adenosarcomas, 9 low-grade endometrial stromal sarcomas, 8 high-grade endometrial stromal sarcomas/undifferentiated endometrial sarcomas, and 3 rhabdomyosarcomas) at our institution. Four of the 67 (6.0%) carcinosarcomas demonstrated abnormal MMR protein expression. Two tumors showed concurrent loss of MLH1 and PMS2 in both the carcinomatous and sarcomatous components. One tumor showed the loss of only PMS2 in both components. The remaining tumor showed an isolated loss of MLH1 and PMS2 in only the small cell carcinoma component, whereas the non-small-cell carcinoma and sarcoma components demonstrated normal staining patterns for MMR proteins. Two of 20 leiomyosarcomas (10%) showed the loss of MMR proteins: one with loss of PMS2 and the other with loss of MSH2 and MSH6. All other uterine sarcoma types examined showed intact MMR protein expression. These observations provide a basis for MMR protein screening in uterine carcinosarcomas and leiomyosarcomas but not in other types of uterine mesenchymal or mixed epithelial/mesenchymal malignancies.
    International Journal of Gynecological Pathology 07/2014; DOI:10.1097/PGP.0b013e31829ff239 · 1.63 Impact Factor
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    ABSTRACT: The evolution of cancer genomes within a single tumor creates mixed cell populations with divergent somatic mutational landscapes. Inference of tumor subpopulations has been disproportionately focused on the assessment of somatic point mutations, whereas computational methods targeting evolutionary dynamics of copy number alterations (CNA) and loss of heterozygosity (LOH) in whole genome sequencing data remain under-developed. We present a novel probabilistic model, TITAN, to infer CNA and LOH events while accounting for mixtures of cell populations, thereby estimating the proportion of cells harboring each event. We evaluate TITAN on idealized mixtures, simulating clonal populations from whole genome sequences taken from genomically heterogeneous ovarian tumor sites collected from the same patient. In addition, we show in 23 whole genomes of breast tumors that inference of CNA and LOH using TITAN critically inform population structure and the nature of the evolving cancer genome. Finally, we experimentally validated subclonal predictions using fluorescence in situ hybridization (FISH) and single-cell sequencing from an ovarian cancer patient sample, thereby recapitulating the key modeling assumptions of TITAN.
    Genome Research 07/2014; 24(11). DOI:10.1101/gr.180281.114 · 13.85 Impact Factor
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    ABSTRACT: Previously reported findings in Austrian BRCA1/2 mutation carriers suggested a possible dependency of embryos with BRCA1/2 mutations on so-called low alleles of the fragile X mental retardation 1 (FMR1) gene, characterized by less than 26 CGG repeats (CGGn<26). The hypothesis arose from a study reporting highly statistically significant enrichment of low FMR1 alleles, significantly exceeding low allele prevalence in a general population, suggesting embryo lethality of BRCA1/2 mutations, "rescued" by presence of low FMR1 alleles. Such a dependency would also offer an explanation for the so-called "BRCA-paradox," characterized by BRCA1/2 deficient embryonic tissues being anti-proliferative (thereby potentially causing embryo-lethality) but proliferative in malignant tumors, including breast and ovarian cancers. Follow up investigations by other investigators, however, at most demonstrated trends towards enrichment but, mostly, no enrichment at all, raising questions about the original observation and hypothesis. We in this study, therefore, investigated CGGn of the FMR1 gene of 86 anonymized DNA samples from women with various forms of ovarian cancer, and were unable to demonstrate differences in prevalence of low FMR1 alleles either between positive and negative ovarian cancer patients for BRCA1/2 or between ovarian cancer patients and reported rates in non-cancer populations. This raises further questions about a suggested dependency between BRCA1/2 and FMR1, but also raises the possibility that investigated Austrian BRCA1/2 carrier populations differ from those in other countries. Either only selected BRCA1/2 mutations, therefore, interact with low FMR1 alleles or the Austrian data reflect only coincidental observations.
    PLoS ONE 07/2014; 9(7):e102370. DOI:10.1371/journal.pone.0102370 · 3.53 Impact Factor

Publication Stats

9k Citations
1,231.36 Total Impact Points

Institutions

  • 1989–2015
    • Vancouver General Hospital
      • Department of Pathology and Laboratory Medicine (UBC)
      Vancouver, British Columbia, Canada
  • 1987–2015
    • University of British Columbia - Vancouver
      • • Department of Pathology and Laboratory Medicine
      • • Department of Obstetrics and Gynaecology
      • • Genetic Pathology Evaluation Center (GPEC)
      Vancouver, British Columbia, Canada
  • 2013
    • Memorial Sloan-Kettering Cancer Center
      • Department of Pathology
      New York City, NY, United States
  • 2008–2013
    • BC Cancer Agency
      Vancouver, British Columbia, Canada
  • 2011
    • Memorial University of Newfoundland
      St. John's, Newfoundland and Labrador, Canada
  • 2008–2011
    • Vancouver Coastal Health
      Vancouver, British Columbia, Canada
  • 2005–2011
    • The University of Calgary
      • Department of Pathology and Laboratory Medicine
      Calgary, Alberta, Canada
    • The Chinese University of Hong Kong
      • Department of Anatomical and Cellular Pathology
      Hong Kong, Hong Kong
  • 2010
    • Tabriz University of Medical Sciences
      • Department of Pathology
      Tabrīz, East Azarbaijan, Iran
    • King Fahad Hospital Medina La Munawarah Kingdom Of Saudi Arabia
      Al Madīnah al Munawwarah, Al Madīnah, Saudi Arabia
  • 2007
    • Prince of Wales Hospital, Hong Kong
      Chiu-lung, Kowloon City, Hong Kong
  • 2002–2007
    • Stanford University
      • • Department of Pathology
      • • Department of Biochemistry
      Palo Alto, California, United States
  • 2004
    • Stanford Medicine
      Stanford, California, United States
  • 2003
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States
  • 1991–1995
    • Fox Chase Cancer Center
      • • Department of Medical Oncology
      • • Department of Pathology
      Filadelfia, Pennsylvania, United States