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Showing papers by "Paul J. van Diest published in 2016"


Journal ArticleDOI
TL;DR: It is found that epithelial-mesenchymal plasticity supports migration but additionally eliminates stemness-enhanced metastatic outgrowth differences, and renders any EMT-induced stemness differences irrelevant for metastaticOutgrowth.

269 citations


Journal ArticleDOI
TL;DR: Evaluated at the pre-clinical level a recently introduced format of targeted PDT, which employs nanobodies as targeting agents and a water-soluble PS that is traceable through optical imaging, shows that these EGFR targeted nanobody–PS conjugates are selective and able to induce tumor cell death in vivo.

116 citations


Journal ArticleDOI
16 Aug 2016-PLOS ONE
TL;DR: An object-level interobserver study between three human observers and an automatic method of mitosis counting revealed that pathologists often do not agree on individual objects, even if this is not reflected in the mitotic count, which suggests that adding a size constraint in theMitosis counting protocol can improve reproducibility.
Abstract: BACKGROUND: Tumor proliferation speed, most commonly assessed by counting of mitotic figures in histological slide preparations, is an important biomarker for breast cancer. Although mitosis counting is routinely performed by pathologists, it is a tedious and subjective task with poor reproducibility, particularly among non-experts. Inter- and intraobserver reproducibility of mitosis counting can be improved when a strict protocol is defined and followed. Previous studies have examined only the agreement in terms of the mitotic count or the mitotic activity score. Studies of the observer agreement at the level of individual objects, which can provide more insight into the procedure, have not been performed thus far. METHODS: The development of automatic mitosis detection methods has received large interest in recent years. Automatic image analysis is viewed as a solution for the problem of subjectivity of mitosis counting by pathologists. In this paper we describe the results from an interobserver agreement study between three human observers and an automatic method, and make two unique contributions. For the first time, we present an analysis of the object-level interobserver agreement on mitosis counting. Furthermore, we train an automatic mitosis detection method that is robust with respect to staining appearance variability and compare it with the performance of expert observers on an "external" dataset, i.e. on histopathology images that originate from pathology labs other than the pathology lab that provided the training data for the automatic method. RESULTS: The object-level interobserver study revealed that pathologists often do not agree on individual objects, even if this is not reflected in the mitotic count. The disagreement is larger for objects from smaller size, which suggests that adding a size constraint in the mitosis counting protocol can improve reproducibility. The automatic mitosis detection method can perform mitosis counting in an unbiased way, with substantial agreement with human experts.

96 citations


Journal ArticleDOI
TL;DR: The results show that MR-HIFU ablation with the dedicated breast system is safe and results in histopathologically proven tumour necrosis.
Abstract: Objectives To assess the safety and feasibility of MRI-guided high-intensity focused ultrasound (MR-HIFU) ablation in breast cancer patients using a dedicated breast platform.

74 citations


Journal ArticleDOI
TL;DR: It is concluded that common decalcification procedures have only a modest negative influence on hormone and HER2 receptor immunohistochemistry in breast cancer, but they may seriously affect DNA/RNA-based diagnostic procedures.

62 citations


Journal ArticleDOI
TL;DR: These results demonstrate the successful generation of a CAIX-specific nanobody-IRDye800CW conjugate that can be used for rapid imaging of (pre-)invasive breast cancer.
Abstract: Purpose The aim of this work was to develop a CAIX-specific nanobody conjugated to IRDye800CW for molecular imaging of pre-invasive breast cancer.

55 citations


Journal ArticleDOI
TL;DR: Results indicate that blocking DDX3 by RK-33 in combination with radiation treatment is a viable option for treating locally advanced prostate cancer.
Abstract: Despite advances in diagnosis and treatment, prostate cancer is the most prevalent cancer in males and the second highest cause of cancer-related mortality. We identified an RNA helicase gene, DDX3 (DDX3X), which is overexpressed in prostate cancers, and whose expression is directly correlated with high Gleason scores. Knockdown of DDX3 in the aggressive prostate cancer cell lines DU145 and 22Rv1 resulted in significantly reduced clonogenicity. To target DDX3, we rationally designed a small molecule, RK-33, which docks into the ATP-binding domain of DDX3. Functional studies indicated that RK-33 preferentially bound to DDX3 and perturbed its activity. RK-33 treatment of prostate cancer cell lines DU145, 22Rv1, and LNCaP (which have high DDX3 levels) decreased proliferation and induced a G1 phase cell-cycle arrest. Conversely, the low DDX3–expressing cell line, PC3, exhibited few changes following RK-33 treatment. Importantly, combination studies using RK-33 and radiation exhibited synergistic effects both in vitro and in a xenograft model of prostate cancer demonstrating the role of RK-33 as a radiosensitizer. Taken together, these results indicate that blocking DDX3 by RK-33 in combination with radiation treatment is a viable option for treating locally advanced prostate cancer. Cancer Res; 76(21); 6340–50. ©2016 AACR.

54 citations


Journal ArticleDOI
TL;DR: The feasibility of the use of VHH ‘cocktails’ to increase T/B ratios and improve early detection of heterogeneous tumours is established and multispectral molecular imaging is used to facilitate the assessment of the target expression status of tumours and metastases, both invasive or non-invasively.
Abstract: Optical molecular imaging is an emerging novel technology with applications in the diagnosis of cancer and assistance in image-guided surgery. A high tumour-to-background (T/B) ratio is crucial for successful imaging, which strongly depends on tumour-specific probes that rapidly accumulate in the tumour, while non-bound probes are rapidly cleared. Here, using pre-invasive breast cancer as a model, we investigate whether the use of combinations of probes with different target specificities results in higher T/B ratios and whether dual-spectral imaging leads to improvements in tumour characterization. We performed optical molecular imaging of an orthotopic breast cancer model mimicking ductal carcinoma in situ (DCIS). A combination of carbonic anhydrase IX (CAIX)- and human epidermal growth factor receptor 2 (HER2)-specific variable domains of the heavy chain from heavy-chain antibodies (VHHs) was conjugated either to the same fluorophore (IRDye800CW) to evaluate T/B ratios or to different fluorophores (IRDye800CW, IRDye680RD or IRDye700DX) to analyse the expression of CAIX and HER2 simultaneously through dual-fluorescence detection. These experiments were performed non-invasively in vivo, in a mimicked intra-operative setting, and ex vivo on tumour sections. Application of the CAIX- and HER2-specific VHH combination resulted in an increase of the T/B ratio, as compared to T/B ratios obtained from each of these single VHHs together with an irrelevant VHH. This dual tumour marker-specific VHH combination also enabled the detection of small metastases in the lung. Furthermore, dual-spectral imaging enabled the assessment of the expression status of both CAIX and HER2 in a mimicked intra-operative setting, as well as on tumour sections, which was confirmed by immunohistochemistry. These results establish the feasibility of the use of VHH ‘cocktails’ to increase T/B ratios and improve early detection of heterogeneous tumours and the use of multispectral molecular imaging to facilitate the assessment of the target expression status of tumours and metastases, both invasive or non-invasively.

46 citations


Journal ArticleDOI
TL;DR: Overall, the rates of LR and RR in young patients with early-stage breast cancer were relatively low and varied by biomarker subtype.
Abstract: PurposeThe aim of this study was to evaluate contemporary rates of local recurrence (LR) and regional recurrence (RR) in young patients with breast cancer in relation to tumor biology as expressed by biomarker subtypes.Patients and MethodsWomen < 35 years of age who underwent surgery for primary unilateral invasive breast cancer between 2003 and 2008 were selected from the Netherlands Cancer Registry. Patients were categorized according to biomarker subtypes on the basis of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. The 5-year risks of developing LR and regional lymph node recurrence were estimated by using Kaplan-Meier statistics.ResultsA total of 1,000 patients were identified, of whom 59% had a known subtype: 39% HR-positive/HER2-negative; 17% HR-positive/HER2-positive; 10% HR-negative/HER2-positive; and 34% HR-negative/HER2-negative (triple negative). Overall 5-year LR and RR rates were 3.5% and 3.7%, respectively. A decreasing trend for both rates was observed o...

43 citations


Journal ArticleDOI
TL;DR: The proportion of BCs classified as luminal A-like is highly influenced by the Ki67-LI assessment method, which may have a direct effect on the proportion of patients considered having low-risk disease and thus influence therapeutic decision making.
Abstract: Ki67 has been proposed as prognostic proliferation marker in luminal breast cancer (BC), but little is known on the influence of Ki67 assessment methods on subtyping into luminal A- and B-like tumors. Our aim was to study the influence of different Ki67-labeling index (Ki67-LI) assessment methods on the proportion of BCs classified as luminal A-like. 280 early BCs were subtyped according to the St Gallen 2015 definitions into 71 % luminal (HER2 negative), 6 % luminal B-like (HER2 positive), 13 % triple negative, 1 % HER2 positive (nonluminal), and 9 % special type. Digitized whole slides were counted manually on the screen. We used nine defined counting methods to assess the Ki67-LI (including the International Ki67 in Breast Cancer Working Group recommendations), and compared the resulting medians and the proportions of cancers classified as luminal A-like according to the formerly used cut-off <20 %. Methods assessing hot spots and tumor periphery resulted in significantly higher Ki67-LI medians than those measuring an average proliferation (27.45 % vs 16.96 %, p < 0.0001). Substantially lower median Ki67-LI were found when assessing 1020 compared to counting 100, 200, 300 cells (17.65 vs 33 %, vs 28 %, vs 24.33 %, respectively; p < 0.0001), or 510 cells (20.59 %, p = 0.019). Applying a standard Ki67-LI cut-off <20 % to define low proliferation for all methods, the proportion of luminal A-like cancers varied between 13 and 44 %. The proportion of BCs classified as luminal A-like is highly influenced by the Ki67-LI assessment method. As a consequence, the selection of a specific Ki67-LI assessment method may have a direct effect on the proportion of patients considered having low-risk disease and thus influence therapeutic decision making. This calls for a standardized assessment method.

41 citations


Journal ArticleDOI
TL;DR: Fibroblast growth factor receptor 3 protein is frequently overexpressed in oral and oropharyngeal squamous cell carcinoma and may serve as a potential therapeutic target for FGFR3‐directed therapies in oral
Abstract: Fibroblast growth factor receptor 3 (FGFR3) is a member of the fibroblast growth factor receptor tyrosine kinase family. It has been identified as a promising therapeutic target in multiple types of cancer. We have investigated FGFR3 protein expression and FGFR3 gene copy-numbers in a single well-documented cohort of oral and oropharyngeal squamous cell carcinoma. Tissue microarray sets containing 452 formalin-fixed paraffin-embedded tissues were immunohistochemically stained with an anti-FGFR3 antibody and hybridized with a FGFR3 fluorescence in situ hybridization probe. FGFR3 protein expression was correlated with clinicopathological and survival data, which were retrieved from electronic medical records. FGFR3 mRNA data of 522 head and neck squamous cell carcinoma (HNSCC) were retrieved from The Cancer Genome Atlas (TCGA). Fibroblast growth factor receptor 3 (FGFR3) protein was overexpressed in 48% (89/185) of oral and 59% (124/211) of oropharyngeal squamous cell carcinoma. Overexpression of FGFR3 protein was not related to overall survival or disease-free survival in oral (HR[hazard ratio]: 0.94; 95% CI: 0.64-1.39; P = 0.77, HR: 0.94; 95% CI: 0.65-1.36; P = 0.75) and oropharyngeal squamous cell carcinoma (HR: 1.21; 95% CI: 0.81-1.80; P = 0.36, HR: 0.42; 95% CI: 0.79-1.77; P = 0.42). FGFR3 mRNA was upregulated in 3% (18/522) of HNSCC from the TCGA. The FGFR3 gene was gained in 0.6% (1/179) of oral squamous cell carcinoma but no amplification was found in oral and oropharyngeal squamous cell carcinoma. In conclusion, FGFR3 protein is frequently overexpressed in oral and oropharyngeal squamous cell carcinoma. Therefore, it may serve as a potential therapeutic target for FGFR3-directed therapies in oral and oropharyngeal squamous cell carcinoma.

Journal ArticleDOI
TL;DR: This work characterize the EMSY/KDM5A/SIN3B complex in detail by quantitative interaction proteomics and ChIP-sequencing and identifies a novel substoichiometric interactor of the complex, transcription factor ZNF131, which recruits EMSY to a large number of active, H3K4me3 marked promoters.

Journal ArticleDOI
TL;DR: Evidence is presented for the existence of two parallel pathogenetic pathways in oral SCCs, characterized by the expression of low- and high-molecular weight CKs.
Abstract: Squamous cell carcinoma (SCC) of the oral cavity is a morphological heterogeneous disease. Various cytokeratin (CK) expression patterns with different prognostic values have been described, but little is known concerning the underlying biological cell mechanisms. Therefore, the present study investigated 193 cases of oral SCCs using immunohistochemistry for α/β/γ-catenin, glucose transporter 1, caspase-3, X-linked inhibitor of apoptosis protein, hypoxia inducible factor-1α, carbonic anhydrase 9, heat shock protein (hsp) 70, mast/stem cell growth factor receptor, p21, p27, p16, p53, B-cell lymphoma 6, epidermal growth factor receptor, cyclin D1 and CK1, 5/6, 8/18, 10, 14 and 19. Expression patterns were analyzed with biomathematical permutation analysis. The present results revealed a significant association between the expression of low-molecular weight CK8/18 and 19 and a high-tumor grade, β and γ-catenin expression, deregulated cell cycle proteins and a predominant localization of the tumor on the floor of the mouth. By contrast, expression of high-molecular weight CK1, 5/6, 10 and 14 was significantly associated with the expression of p21 and hsp70. In conclusion, the current study presents evidence for the existence of two parallel pathogenetic pathways in oral SCCs, characterized by the expression of low- and high-molecular weight CKs. Additional studies are required to demonstrate the extent that these results may be used to improve therapeutic regimens.

Journal ArticleDOI
TL;DR: Evidence was found for prognostic value of FGFR1 expression in cancer-associated fibroblasts in HNSCC and the need for future well-conducted prognostic studies is emphasized.
Abstract: Background Since head and neck cancer is characterized by poor survival rates, there is a demand for novel therapeutic targets and prognostic biomarkers. An upcoming therapeutic target is the fibroblast growth factor receptor (FGFR) family. However, their prognostic role in head and neck cancer remains unclear.

Journal ArticleDOI
TL;DR: The aim was to study the influence of biopsy size on agreement rates for histological grade between CNBs and subsequent surgical excision biopsies (SEBs).
Abstract: Aims In breast cancer patients undergoing neoadjuvant chemotherapy, histological grading needs to be performed on core needle biopsies (CNBs) that may not be representative of the whole tumour when they are small. Our aim was to study the influence of biopsy size on agreement rates for histological grade between CNBs and subsequent surgical excision biopsies (SEBs). Methods and results We calculated agreement and Cohen's κ between CNBs and SEBs of 300 early-stage breast cancers. The number of cores, total core length, total tumour length and tumour/tissue ratio were assessed for each CNB set. Agreement rates for grade were calculated for different classes of core number and tumour/tissue ratio, and for total core lengths and tumour lengths per CNB set in 5–15-mm intervals. Agreement on grade between CNBs and SEBs was 73% (κ = 0.59), with underestimation of grade in CNBs in 26% of cases and overestimation in 1% of cases. There was significantly higher concordance between CNBs and SEBs at a total core length of ≥50 mm than at a total core length of <50 mm (83% versus 68% agreement, P = 0.007), at a tumour length of ≥15 mm than at tumour length of <15 mm in CNBs (79% versus 67% agreement, P = 0.036), and at three or more cores than at fewer than three cores (75% versus 58% agreement, P = 0.048). The tumour/tissue ratio, pathological tumour size and radiological tumour size were not statistically different between concordant and discordant cases. Conclusions Agreement rates for histological grade in CNBs versus SEBs improve with increasing biopsy sample size.

Journal ArticleDOI
TL;DR: The aim was to study the intratumoral heterogeneity of Ki67 expression in early breast cancers and its association with clinicopathological features, such as oestrogen receptor (ER) status, grade and histological subtype.
Abstract: Aims: Regional differences in proliferative activity are commonly seen within breast cancers, but little is known on the extent of intratumoral heterogeneity of Ki67 expression. Our aim was to study the intratumoral heterogeneity of Ki67 expression in early breast cancers and its association with clinicopathological features, such as oestrogen receptor (ER) status, grade and histological subtype. Methods and results: The Ki67-labelling index (Ki67-LI) was assessed in hot, cold and intermediate spots of 233 invasive breast cancers by counting a total of 1020 cells, according to a protocol of the International Ki67 in Breast Cancer Working Group. Differences between the spots per tumour were analysed further for clinicopathological subgroups defined by ER status, grade and histological subtype. All clinicopathological subgroups showed significant differences in Ki67-LI between hot, intermediate and cold spots (P <0.0001). The coefficient of variance (CV) between the spots was higher in ER-positive than in ER-negative cancers (72.6 versus 49.2%, P <0.0001), and was highest in grade 3 (96.12%), grade 1 (87.27%) and invasive lobular tumours (83.59%) and lowest in medullary (26.48%) cancers. Nested analysis of variance indicated that in both ER-positive and ER-negative cancers, variance in Ki67-LI within tumours contributed more to the total variance (56% for ER-positive, 60% for ER-negative cancers) than the variance between tumours. Conclusion: Intratumoral heterogeneity in Ki67-LI is a ubiquitous phenomenon across various pathological subgroups of breast cancer that may impact assessment of Ki67 levels for clinical decision-making, and sheds new light on recommended cut-offs.

Journal ArticleDOI
TL;DR: Cancerous nipple fluid contains increased levels of methylation of tumor suppressor genes that potentially could serve as a biomarker for early breast cancer detection.
Abstract: // Jolien S. de Groot 1 , Cathy B. Moelans 1 , Sjoerd G. Elias 2 , Mary Jo Fackler 3 , Robert van Domselaar 1 , Karijn P.M. Suijkerbuijk 1 , Arjen J. Witkamp 4 , Saraswati Sukumar 3 , Paul J. van Diest 1 , Elsken van der Wall 5 1 Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands 2 Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands 3 Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, USA 4 Department of Surgery, University Medical Center Utrecht, Utrecht, The Netherlands 5 Department of Medical Oncology, University Medical Center Utrecht, Utrecht, The Netherlands Correspondence to: Elsken van der Wall, e-mail: e.vanderwall@umcutrecht.nl Keywords: nipple fluid, methylation, breast cancer Received: December 10, 2015 Accepted: February 29, 2016 Published: March 25, 2016 ABSTRACT Introduction : Nipple fluid aspiration provides direct non-invasive sampling of fluid from the mammary ductal system, where the majority of breast cancers originate. DNA promoter hypermethylation (“methylation”) occurs early and at high frequency in breast carcinogenesis, bearing the potential as a biomarker for cancer detection at its earliest stages. We assessed methylation in nipple fluid from breasts of healthy women, of women with sporadic breast cancer and of their contralateral breasts. Our goal was to investigate whether nipple fluid can be used as a reliable methylation biomarker source. Methods : Methylation levels of 13 genes were analysed by quantitative multiplex-methylation specific PCR (QM-MSP) in nipple fluid samples from breasts of healthy women, and from the affected and contralateral breasts of breast cancer patients. Results : Methylation analysis of the low-volume nipple fluid samples was feasible. Despite the generally low methylation levels, cancerous and healthy breasts nipple fluid could be discriminated with an area under the receiver operating characteristic curve (AUC) of 0.64 (p<0.01) based on a multivariate model including AKR1B1, ALX1, RASSF1A and TM6SF1 . Within-patient differences between cancerous and contralateral nipple fluid samples were less prominent. Conclusions : Cancerous nipple fluid contains increased levels of methylation of tumor suppressor genes that potentially could serve as a biomarker for early breast cancer detection.

Journal ArticleDOI
TL;DR: FGFR family members are frequently highly expressed in OCSCC and OPSCC and are therefore potential targets for novel therapies that are urgently required to improve survival of O CSCC andOPSCC patients.
Abstract: Introduction Fibroblast growth factor receptor family member proteins (FGFR1–4) have been identified as promising novel therapeutic targets and prognostic markers in a wide spectrum of solid tumors. The present study investigates the expression and prognostic value of four FGFR family member proteins in a large multicenter oral cavity squamous cell carcinoma (OCSCC) and oropharyngeal squamous cell carcinoma (OPSCC) cohort.

Journal ArticleDOI
TL;DR: It is found that p120 regulates actomyosin contractility through concomitant binding to RhoA and the centralspindlin component MKLP1, independent of cadherin association.
Abstract: Spatiotemporal activation of RhoA and actomyosin contraction underpins cellular adhesion and division. Loss of cell-cell adhesion and chromosomal instability are cardinal events that drive tumour progression. Here, we show that p120-catenin (p120) not only controls cell-cell adhesion, but also acts as a critical regulator of cytokinesis. We find that p120 regulates actomyosin contractility through concomitant binding to RhoA and the centralspindlin component MKLP1, independent of cadherin association. In anaphase, p120 is enriched at the cleavage furrow where it binds MKLP1 to spatially control RhoA GTPase cycling. Binding of p120 to MKLP1 during cytokinesis depends on the N-terminal coiled-coil domain of p120 isoform 1A. Importantly, clinical data show that loss of p120 expression is a common event in breast cancer that strongly correlates with multinucleation and adverse patient survival. In summary, our study identifies p120 loss as a driver event of chromosomal instability in cancer.

Journal ArticleDOI
Menashe Zaaroor1, Alon Sinai1, Dorit Goldsher1, Ayelet Eran1  +657 moreInstitutions (98)
TL;DR: In vivo T2 -based MR thermometry in adipose tissue layers for high-intensity focused ultrasound near-field monitoring with real-time monitoring of T2-based and T1-based thermometry is presented.

Journal ArticleDOI
TL;DR: Proteome profiling of secretome using murine breast tumor models is a powerful strategy to identify non-invasive candidate biomarkers of BRCA1-deficient breast cancer.
Abstract: Breast cancer arising in female BRCA1 mutation carriers is characterized by an aggressive phenotype and early age of onset. We performed tandem mass spectrometry-based proteomics of secretomes and exosome-like extracellular vesicles from BRCA1-deficient and BRCA1-proficient murine breast tumor models to identify extracellular protein biomarkers, which can be used as an adjunct to current diagnostic modalities in patients with BRCA1-deficient breast cancer. We identified 2,107 proteins, of which 215 were highly enriched in the BRCA1-deficient secretome. We demonstrated that BRCA1-deficient secretome proteins could cluster most human BRCA1- and BRCA2-related breast carcinomas at the transcriptome level. Topoisomerase I (TOP1) and P-cadherin (CDH3) expression was investigated by immunohistochemistry on tissue microarrays of a large panel of 253 human breast carcinomas with and without BRCA1/2 mutations. We showed that expression of TOP1 and CDH3 was significantly increased in human BRCA1-related breast carcinomas relative to sporadic cases (p = 0.002 and p < 0.001, respectively). Multiple logistic regression showed that TOP1 (adjusted odds ratio [OR] 3.75; 95% confidence interval [95% CI], 1.85 - 7.71, p < 0.001) as well as CDH3 positivity (adjusted OR 2.45; 95% CI, 1.08 - 5.49, p = 0.032) were associated with BRCA1/2-related breast carcinomas after adjustment for triple-negative phenotype and age. In conclusion, proteome profiling of secretome using murine breast tumor models is a powerful strategy to identify non-invasive candidate biomarkers of BRCA1-deficient breast cancer. We demonstrate that TOP1 and CDH3 are closely associated to BRCA1-deficient breast cancer. These data merit further investigation for early detection of tumors arising in BRCA1 mutation carriers.

Journal ArticleDOI
TL;DR: This large nationwide cohort demonstrates considerable interlaboratory and intralaboratory variation in differentiation grading of CRC, and better standardization of grading criteria is needed for optimal determination of prognosis and treatment selection.
Abstract: Differentiation grade of colorectal adenocarcinoma (CRC) is a prognostic factor and important for therapy selection. In patients with stage II colon cancer, poor differentiation is an indication for adjuvant chemotherapy. The variability in daily practice in the grading of CRC was assessed in a nationwide cohort. Using the Dutch Pathology Registry (PALGA), all synoptically reported CRC resections from 2010 to 2013 were identified. Proportions of poorly differentiated (PD) adenocarcinomas were determined and compared between 35 laboratories by univariable and multivariable logistic regression analyses. In total, 11,719 resections of 11,681 patients were included, of which 1427 (12.2%) were PD (range between 35 laboratories: 5.0% to 33.2%). After adjustment for case mix, 4 (11%) laboratories still reported a significantly lower (n=2) or higher (n=2) proportion of PD adenocarcinoma compared with the reference laboratory. Seven of 8 investigated laboratories showed considerable intralaboratory variation between pathologists as well. In a subgroup of 2812 patients (2813 tumors) who could have been eligible for adjuvant chemotherapy solely on the basis of the differentiation grade (stage II colon cancer patients without other high-risk factors [ie, T4, <10 lymph nodes evaluated, perforation, ileus, or angioinvasion]), 258 (9.2%) were PD (range between laboratories: 0% to 22.7%). In this subgroup, 4 laboratories still diagnosed significantly more PD adenocarcinomas after multivariable logistic regression analysis, increasing the number of colon cancer patients eligible for adjuvant therapy. In conclusion, this large nationwide cohort demonstrates considerable interlaboratory and intralaboratory variation in differentiation grading of CRC. Better standardization of grading criteria is needed for optimal determination of prognosis and treatment selection.

Journal ArticleDOI
TL;DR: The aim of this study was to analyse, in a nationwide cohort of colorectal adenomas, the interlaboratory variability in the grading of dysplasia in daily practice.
Abstract: AIMS: Although high-grade dysplasia (HGD) is a risk factor for malignant transformation and future development of adenomas/carcinomas, grade is not incorporated in the Dutch guidelines for colonoscopy surveillance, partly due to presumed interobserver variability. In a nationwide cohort of colorectal adenomas, we analysed the interlaboratory variability in the grading of dysplasia in daily practice. METHODS AND RESULTS: Using the Dutch Pathology Registry (PALGA), all synoptically reported classic adenomas in The Netherlands in 2013 were identified. Proportion of adenomas with HGD was determined for biopsies and polypectomies and compared between 37 laboratories by multivariable logistic regression analyses. In total, 21,030 colonoscopies of 20,270 patients were included. HGD was reported in 530 (3.6%) out of 14,866 adenomas diagnosed on biopsies (range between laboratories: 0%-13.6%) and in 983 (11.8%) out of 8,346 adenomas diagnosed on polypectomies (range 3.1%-42.9%). After adjustment for case mix, thirteen (35%) laboratories reported a significantly lower or higher frequency of HGD than average. CONCLUSIONS: We observed considerable interlaboratory variation in the grading of dysplasia in colorectal adenomas, which could only be partly explained by differences in case mix. Therefore, better standardization of grading criteria is needed before grade of dysplasia can usefully be incorporated in colonoscopy surveillance guidelines.

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TL;DR: Routine double reading of histopathology specimens prior to multidisciplinary meetings prevents diagnostic errors and resulted in about 1% discordant diagnoses of potential clinical significance, indicating that second review is worthwhile in terms of patient safety and quality of patient care.
Abstract: Aim Double reading may be a valuable tool for improving quality of patient care by identifying diagnostic errors before final sign-out, but standard double reading would significantly increase costs of pathology. We assessed the added value of intradepartmental routine double reading of histopathology specimens prior to multidisciplinary meetings. Methods Diagnoses, treatment plans and prognoses of patients are often discussed at multidisciplinary meetings. As part of the daily routine, all pathology specimens to be discussed at upcoming multidisciplinary meetings undergo prior intradepartmental double reading. We identified all histopathology specimens from 2013 that underwent such double reading and determined major and minor discordance rates based on clinical relevance between the initial and consensus sign-out diagnoses. Results We included 6796 histopathology specimens that underwent double reading, representing approximately 8% of all histopathology cases at our institution in 2013. Double reading diagnoses were concordant in 6566 specimens (96.6%). Major and minor discordances were observed in 60 (0.9%) and 170 (2.5%) specimens, respectively. Urology specimens had significantly more discordances than other tissues of origin, Gleason grading of prostate cancer biopsies being the most frequent diagnostic problem. Furthermore, premalignant and malignant cases showed significantly higher discordance rates than the rest. The vast majority (90%) of discordances represented changes within the same diagnostic category (eg, malignant to malignant). Conclusions Routine double reading of histopathology specimens prior to multidisciplinary meetings prevents diagnostic errors. It resulted in about 1% discordant diagnoses of potential clinical significance, indicating that second review is worthwhile in terms of patient safety and quality of patient care.

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TL;DR: In patients with breast cancer presenting with lobular differentiation at biopsy, preoperative MRI can lead to the detection of additional malignancies and clinically relevant changes in surgical policy in a high percentage of patients, irrespective of the lobular component.

Journal ArticleDOI
TL;DR: Performance and reliability varied significantly between the 4 tested antibodies, and the Merck antibodies seem to be most suitable for faster identification of mitotic hot spots and as potential marker in digital image analysis.
Abstract: BACKGROUND Phosphohistone H3 (PHH3) has been suggested to facilitate and improve mitotic activity assessment in breast cancer and other tumor entities, but the reliability of respective immunohistochemical antibodies has not yet been compared for routine purposes. Our aim was to test the performance of 4 different PHH3 antibodies on a series of highly proliferating breast cancers with good preservation of morphology. METHODS Four commercially available PHH3 antibodies were tested on 9 grade 3 invasive breast cancers processed in the same batch. We analyzed the number of antibody stained and nonstained mitotic figures as well as the total of cells observed in 10 high power fields per tumor to calculate sensitivity, specificity, and accuracy of the respective antibodies for staining mitotic figures, taking morphologically defined mitotic figures as gold standard. RESULTS Sensitivity, specificity, and accuracy of the respective PHH3 antibodies for staining mitotic figures were 54.51%, 99.98%, and 98.79% for Cell Marque, 87.48%, 67.62%, and 67.47% for Epitomics, 98.62%, 99.73%, and 99.49% for Merck 06-570, and 99.74%, 99.52%, and 99.51% for Merck 09-797, respectively. Sensitivity was lowest for telophase. In statistical analysis, the Cell Marque antibody demonstrated significantly lower sensitivity and Epitomics substantially lower sensitivity and specificity than Merck 06-570 and Merck 09-797 antibodies (P<0.0001, respectively). CONCLUSIONS Performance and reliability varied significantly between the 4 tested antibodies. For faster identification of mitotic hot spots and as potential marker in digital image analysis, the Merck antibodies seem to be most suitable.

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TL;DR: This study aimed to compare histopathological features of breast cancer after MR‐HIFU ablation and RFA.
Abstract: AIMS: Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation and radiofrequency ablation (RFA) are being researched as possible substitutes for surgery in breast cancer patients. The histopathological appearance of ablated tissue has not been studied in great detail. This study aimed to compare histopathological features of breast cancer after MR-HIFU ablation and RFA. METHODS AND RESULTS: MR-HIFU ablation and RFA were performed in- and ex-vivo. Tumours in six mastectomy specimens were partially ablated with RFA or MR-HIFU. In-vivo MR-HIFU ablation was performed 3-6 days before excision; RFA was performed in the operation room. Tissue was fixed in formalin and processed to haematoxylin and eosin (H&E) and cytokeratin-8 (CK-8)-stained slides. Morphology and cell viability were assessed. Ex-vivo ablation resulted in clear morphological changes after RFA versus subtle differences after MR-HIFU. CK-8 staining was decreased or absent. H&E tended to underestimate the size of thermal damage. In-vivo MR-HIFU resulted in necrotic-like changes. Surprisingly, some ablated lesions were CK-8-positive. Histopathology after in-vivo RFA resembled ex-vivo RFA, with hyper-eosinophilic stroma and elongated nuclei. Lesion borders were sharp after MR-HIFU and indistinct after RFA. CONCLUSION: Histopathological differences between MR-HIFU-ablated tissue and RF-ablated tissue were demonstrated. CK-8 was more reliable for cell viability assessment than H&E when used directly after ablation, while H&E was more reliable in ablated tissue left in situ for a few days. Our results contribute to improved understanding of histopathological features in breast cancer lesions treated with minimally invasive ablative techniques.

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TL;DR: Testing the validity of WSI in assessing human epidermal growth factor receptor 2 (HER2) status in breast cancer specimens using chromogenic in situ hybridisation (CISH) found there was a reasonable concordance between microscopic scoring and WSI-based scoring of HER2 copy number of CISH slides.
Abstract: Aim Whole slide images (WSIs) have stimulated a paradigm shift from conventional to digital pathology in several applications within pathology. Due to the fact that WSIs have not yet been approved for primary diagnostics, validating their use for different diagnostic purposes is still mandatory. The aim of this study was to test the validity of WSI in assessing human epidermal growth factor receptor 2 (HER2) status in breast cancer specimens using chromogenic in situ hybridisation (CISH). Materials and methods Ninety-six HER2 CISH slides were scored by two observers on a light microscope (400× viewing magnification) and on WSI (40× scanning magnification, one focus plane) with a minimum of 6 weeks washout period. The concordance between digital and microscopic HER2 scores was assessed. Results Digitally, 93/96 cases could be assessed (96.8%). Microscopic and digital evaluation of HER2 amplification status were concordant in 68/93 cases ((73.1%, 95% CI: 0.639 −0.823), κ 0.588). CISH underscoring was most noticeable in the amplified and equivocal categories while the highest level concordance was seen in cases with a normal copy number. Additionally there was a noticeable tendency to underestimate the average HER2 scores on WSI: lower in 59 and higher in 11 cases. There was no major difference in time spent for microscopic scoring (86.9 s) and digital scoring (81.7 s). Conclusions There was a reasonable concordance between microscopic scoring and WSI-based scoring of HER2 copy number of CISH slides. Nevertheless, WSIs scanned on a single focal plane are insufficient to assess HER2 gene amplification status by scoring CISH due to the noticeable tendency towards digitally underestimating the number of HER2 spots. Scanning at multiple focus planes may offer better resolution for improved digital CISH spot counting.

Journal ArticleDOI
TL;DR: Examining the prognostic performance of MPI, NPI, Adjuvant! and Predict prognostic models for male breast cancer patients concluded that these models originally developed and validated for FBC patients perform quite well for MBC patients.
Abstract: Breast cancer in men is uncommon; it accounts for 1 % of all patients with primary breast cancer. Its treatment is mostly extrapolated from its female counterpart. Accurate predictions are essential for adjuvant systemic treatment decision-making and informing patients. Several predictive models are available for female breast cancer (FBC) including the Morphometric Prognostic Index (MPI), Nottingham Prognostic Index (NPI), Adjuvant! Online and Predict. The aim of this study was to examine and compare the prognostic performance of these models for male breast cancer (MBC). The population of this study consists of 166 MBC patients. The prognostic scores of the patients are categorized by good, (moderate) and poor, defined by the test itself (MPI and NPI) or based on tertiles (Adjuvant! Online and Predict). Survival according to prognostic score was compared by Kaplan–Meier analysis and differences were tested by logRank. The prognostic performances were evaluated with C-statistics. Calibration was done with the aim to estimate to what extent the survival rates predicted by Predict were similar to the observed survival rates. All prediction models were capable of discriminating between good, moderate and poor survivors. P-values were highly significant. Comparison between the models using C-statistics (n = 88) showed equal performance of MPI (0.67), NPI (0.68), Adjuvant! Online (0.69) and Predict (0.69). Calibration of Predict showed overestimation for MBC patients. In conclusion, MPI, NPI, Adjuvant! and Predict prognostic models, originally developed and validated for FBC patients, also perform quite well for MBC patients.