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1.
Gastroenterology ; 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33610533

RESUMO

BACKGROUND & AIMS: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. We aim to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment. METHODS: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed prior to a second round of voting. RESULTS: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes Score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley Score and Harpaz Index were uncertain. Histological activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission were considered appropriate and realistic therapeutic targets. Current histological indices require validation for pediatric populations. CONCLUSIONS: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.

2.
Histopathology ; 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33590485

RESUMO

AIMS: To develop and validate a deep learning algorithm to quantify a broad spectrum of histologic features in colorectal carcinoma. METHODS AND RESULTS: A deep learning algorithm was trained on hematoxylin & eosin slides from tissue microarrays of colorectal carcinomas (N=230) to segment colorectal carcinoma digitized images into thirteen regions and one object. The segmentation algorithm demonstrated moderate to almost perfect agreement with interpretations by gastrointestinal pathologists and was applied to an independent test cohort of digitized whole slides of colorectal carcinoma (N=136). The algorithm correctly classified mucinous and high-grade tumours and identified significant differences between mismatch repair proficient and deficient (MMRD) tumours with regards to mucin, inflammatory stroma, and tumor infiltrating lymphocytes (TILs). A cutoff of >44.4 TILs per mm2 carcinoma demonstrated a sensitivity of 88% and specificity of 73% in classifying MMRD carcinomas. Algorithm measures of tumour budding and poorly differentiated clusters (TB/PDC) outperformed TB grade derived from routine sign-out and compared favorably to manual count of TB/PDC with regards to lymphatic, venous, and perineural invasion. Comparable associations were seen between algorithm measures of TB/PDC and manual count of TB/PDC for lymph node metastasis (all P<0.001); however, stronger correlations were seen between the proportion of positive lymph nodes and algorithm measures of TB/PDC. Stronger associations were also seen between distant metastasis and algorithm measures of TB/PDC (P=0.004) compared with TB (P=0.04) and TB/PDC counts (P=0.06). CONCLUSIONS: Our results highlight the potential of deep learning to identify and quantify a broad spectrum of histologic features in colorectal carcinoma.

3.
Gut ; 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33414168

RESUMO

OBJECTIVE: Germline pathogenic variants (PVs) in the DNA mismatch repair (MMR) genes and in the base excision repair gene MUTYH underlie hereditary colorectal cancer (CRC) and polyposis syndromes. We evaluated the robustness and discriminatory potential of tumour mutational signatures in CRCs for identifying germline PV carriers. DESIGN: Whole-exome sequencing of formalin-fixed paraffin-embedded (FFPE) CRC tissue was performed on 33 MMR germline PV carriers, 12 biallelic MUTYH germline PV carriers, 25 sporadic MLH1 methylated MMR-deficient CRCs (MMRd controls) and 160 sporadic MMR-proficient CRCs (MMRp controls) and included 498 TCGA CRC tumours. COSMIC V3 single base substitution (SBS) and indel (ID) mutational signatures were assessed for their ability to differentiate CRCs that developed in carriers from non-carriers. RESULTS: The combination of mutational signatures SBS18 and SBS36 contributing >30% of a CRC's signature profile was able to discriminate biallelic MUTYH carriers from all other non-carrier control CRCs with 100% accuracy (area under the curve (AUC) 1.0). SBS18 and SBS36 were associated with specific MUTYH variants p.Gly396Asp (p=0.025) and p.Tyr179Cys (p=5×10-5), respectively. The combination of ID2 and ID7 could discriminate the 33 MMR PV carrier CRCs from the MMRp control CRCs (AUC 0.99); however, SBS and ID signatures, alone or in combination, could not provide complete discrimination (AUC 0.79) between CRCs from MMR PV carriers and sporadic MMRd controls. CONCLUSION: Assessment of SBS and ID signatures can discriminate CRCs from biallelic MUTYH carriers and MMR PV carriers from non-carriers with high accuracy, demonstrating utility as a potential diagnostic and variant classification tool.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33410551

RESUMO

BACKGROUND: Targeting histological remission or response in Crohn's disease (CD) is not recommended in clinical practice guidelines or as an outcome in clinical trials due to uncertainties regarding index validity and prognostic relevance. AIMS: To conduct a modified RAND/University of California Los Angeles appropriateness process with the goal of producing a framework to standardise histological assessment of CD activity in clinical trials. METHODS: A total of 115 statements generated from literature review and expert opinion were rated on a scale of 1-9 by a panel of 11 histopathologists and 6 gastroenterologists. Statements were classified as inappropriate, uncertain or appropriate based upon the median panel rating and degree of disagreement. RESULTS: The panellists considered it important to measure histological activity in clinical trials to determine efficacy and that absence of neutrophilic inflammation is an appropriate histological target. They were uncertain whether the Global Histological Activity Score was an appropriate instrument for measuring histological activity. The Geboes Score and Robarts Histopathology Index were considered appropriate. Two biopsies from five segments should be biopsied, and the colon and the ileum should be analysed separately for all indices. Endoscopic mucosal appearance should guide biopsy procurement site with biopsies taken from the ulcer edge, or the most macroscopically inflamed area in the absence of ulcers. CONCLUSION: We evaluated the appropriateness of items for assessing histological disease activity in CD clinical trials. These items will be used to develop a novel histological index.

5.
J Mol Diagn ; 23(3): 358-371, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33383211

RESUMO

Patients in whom mismatch repair (MMR)-deficient cancer develops in the absence of pathogenic variants of germline MMR genes or somatic hypermethylation of the MLH1 gene promoter are classified as having suspected Lynch syndrome (SLS). Germline whole-genome sequencing (WGS) and targeted and genome-wide tumor sequencing were applied to identify the underlying cause of tumor MMR deficiency in SLS. Germline WGS was performed on samples from 14 cancer-affected patients with SLS, including two sets of first-degree relatives. MMR genes were assessed for germline pathogenic variants, including complex structural rearrangements and noncoding variants. Tumor tissue was assessed for somatic MMR gene mutations using targeted, whole-exome sequencing or WGS. Germline WGS identified pathogenic MMR variants in 3 of the 14 cases (21.4%), including a 9.5-megabase inversion disrupting MSH2 in a mother and daughter. Excluding these 3 MMR carriers, tumor sequencing identified at least two somatic MMR gene mutations in 8 of 11 tumors tested (72.7%). In a second mother-daughter pair, a somatic cause of tumor MMR deficiency was supported by the presence of double somatic MSH2 mutations in their respective tumors. More than 70% of SLS cases had double somatic MMR mutations in the absence of germline pathogenic variants in the MMR or other DNA repair-related genes on WGS, and, therefore, were confidently assigned a noninherited cause of tumor MMR deficiency.

6.
Histopathology ; 78(1): 88-105, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33382496

RESUMO

Most absorption of nutrients takes place in the proximal small intestine, and the most common disorders leading to malabsorption are associated with a morphological abnormality in the duodenal mucosa that is appreciable in histological sections of biopsy specimens. Coeliac disease is the most well-known example, causing intraepithelial lymphocytosis, inflammation and villous atrophy in the duodenum. Remarkably similar inflammatory changes can be induced by other processes, including medications, e.g. angiotensin II receptor blockers and immune checkpoint inhibitors, immune dysregulation disorders, e.g. common variable immunodeficiency and autoimmune enteropathy, infections, collagenous sprue, and tropical sprue. However, there are often subtle histological differences from coeliac disease in the type of inflammatory infiltrate, the presence of crypt apoptosis, and the extent and type of inflammation beyond the duodenum. The clinical setting and serological investigation usually allow diagnostic separation, but some cases remain challenging. Histopathology is also important in assessing the response to treatment, such as the change in villous architecture caused by a gluten-free diet, or the response to cessation of a potentially causative medication. This review examines the practical role that histopathology of duodenal biopsy specimens plays in the assessment and management of inflammatory malabsorptive processes of the proximal small intestine, with a particular emphasis on coeliac disease.

7.
Histopathology ; 77(4): 622-630, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32590886

RESUMO

BACKGROUND: Secondary carcinoma involving the gastrointestinal (GI) tract is an uncommon finding in biopsy specimens. The diagnosis can be challenging for tumours mimicking a primary carcinoma and when the clinical context is unknown. METHODS AND RESULTS: A multicentre retrospective study was performed to evaluate the clinical and histological features of a series of secondary carcinoma in GI biopsies. A total of 197 cases from 190 patients (median age = 67 years; 57% females) were reviewed. In 16% of patients, the primary carcinoma was unknown. Most lesions presented endoscopically as mucosal or submucosal masses (58%). In 13%, the endoscopy was non-suspicious for malignancy. The most common tumours were carcinomas of the breast (38%), kidney (13%), lung (12%), prostate (8%) and ovary (7%). The sites of involvement were the stomach (34%), colon (27%), rectum (18%), duodenum (13%), oesophagus (5%), jejunum (3%) and anus (0.5%). Histological patterns of infiltration were mucosal (76%), submucosal (41%), lymphatic (14%), and epithelial colonisation (8%). Submucosal infiltration was found significantly more frequently in carcinomas of the prostate (67%) and lung (62%), compared with carcinomas of the ovary (27%) and breast (23%). Histological obstructive changes were observed in 36% of all cases, with the highest rate in prostate carcinoma (53%) and the lowest rate in kidney carcinoma (8%). CONCLUSION: Awareness of the main clinical and histological patterns of secondary carcinomas in GI tract biopsies may help pathologists to raise the possibility of this uncommon diagnosis and confirm it with the judicious use of immunohistochemistry.

8.
Hum Pathol ; 97: 19-28, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31917154

RESUMO

Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal carcinoma. The significance of serrated lesions resembling traditional serrated adenoma (TSA) in IBD patients is unclear. In this retrospective study, we analyzed 52 TSA-like lesions arising in 30 IBD patients and diagnosed in colectomy or endoscopic specimens. The 27 colectomy lesions presented predominantly as ill-defined areas with granular appearance, with a median size of 15 mm, located throughout the large bowel and associated with synchronous advanced colorectal lesions in 58%. Low-grade serrated dysplasia was present in 56%, high-grade serrated dysplasia in 37%, and TSA-type cytology in 7%. Increased Ki-67 immunostaining and abnormal p53 expression were identified in 96% and 48%, respectively; 74% had a KRAS mutation, and 4% had a BRAF mutation. Endoscopically resectable TSA-like lesions were all discrete polypoid lesions, smaller in size (median 9 mm), predominantly in the distal large bowel, with an adjacent precursor polyp in 24%, and associated with synchronous and metachronous advanced colorectal lesions in 6%. Most (92%) show TSA-type cytology. p53 overexpression was present in 4%, KRAS mutation in 41%, and BRAF mutation in 32%. None of the 52 TSA-like lesions demonstrated loss of MLH1 or SATB2 expression by immunohistochemistry. On follow-up, 4 patients were diagnosed with colorectal carcinoma or high-grade adenomatous IBD-associated dysplasia. None of the patients with lesions showing TSA-type cytology only developed an advanced lesion. Our findings suggest that some TSA-like lesions, essentially from colectomy, may represent a form of IBD-associated dysplasia associated with an increased risk of advanced neoplasia.


Assuntos
Pólipos Adenomatosos/patologia , Carcinoma/patologia , Colite Ulcerativa/patologia , Pólipos do Colo/patologia , Neoplasias Colorretais/patologia , Doença de Crohn/patologia , Lesões Pré-Cancerosas/patologia , Pólipos Adenomatosos/química , Pólipos Adenomatosos/genética , Pólipos Adenomatosos/cirurgia , Adulto , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Carcinoma/química , Carcinoma/genética , Carcinoma/cirurgia , Colectomia , Colite Ulcerativa/genética , Colite Ulcerativa/metabolismo , Colite Ulcerativa/cirurgia , Pólipos do Colo/química , Pólipos do Colo/genética , Pólipos do Colo/cirurgia , Colonoscopia , Neoplasias Colorretais/química , Neoplasias Colorretais/genética , Neoplasias Colorretais/cirurgia , Doença de Crohn/genética , Doença de Crohn/metabolismo , Doença de Crohn/cirurgia , Progressão da Doença , Feminino , Humanos , Antígeno Ki-67/análise , Masculino , Pessoa de Meia-Idade , Mutação , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/cirurgia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Estudos Retrospectivos , Resultado do Tratamento , Proteína Supressora de Tumor p53/análise , Adulto Jovem
9.
Gastroenterology ; 158(1): 137-150.e1, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31476299

RESUMO

BACKGROUND & AIMS: Stenosis is a common complication of Crohn's disease (CD) that has no effective medical therapy. Development of antifibrotic agents will require testing in randomized controlled trials. Computed tomography enterography- and magnetic resonance enterography-based technologies might be used to measure outcomes in these trials. These approaches have been validated in studies of patients with symptomatic strictures who underwent imaging evaluations followed by resection with histopathologic grading of the intestinal tissue for inflammation and/or fibrosis (the reference standard). Imaging findings have correlated with findings from quantitative or semiquantitative histologic evaluation of the degree of fibromuscular stenosis and/or inflammation on the resection specimen. However, it is not clear whether histologic findings are an accurate reference standard. We performed a systematic review of all published histologic scoring systems used to assess stenosing CD. METHODS: We performed a comprehensive search of Embase and MEDLINE of studies through March 13, 2019, that used a histologic scoring system to characterize small bowel CD and assessed inflammatory and fibrotic alterations within the same adult individual. All scores fitting the criteria were included in our analysis, independent of the presence of stricturing disease, as long as inflammation and fibrosis were evaluated separately but in the same scoring system. RESULTS: We observed substantial heterogeneity among the scoring systems, which were not derived from modern principles for evaluative index development. None had undergone formal validity or reliability testing. None of the existing indices had been constructed according to accepted methods for the development of evaluative indices. Basic knowledge regarding their operating properties were lacking. Specific indices for evaluating the important pathologic component of myofibroblast hypertrophy or hyperplasia have not been proposed. CONCLUSIONS: In a systematic review of publications, we found a lack of validated histopathologic scoring systems for assessment of fibromuscular stenosis. Data that describe the operating properties of existing cross-sectional imaging techniques for stenosing CD should be questioned. Development and validation of a histopathology index is an important research priority.


Assuntos
Constrição Patológica/diagnóstico , Doença de Crohn/complicações , Íleo/patologia , Índice de Gravidade de Doença , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Fibrose , Humanos , Íleo/diagnóstico por imagem , Íleo/cirurgia , Imagem por Ressonância Magnética , Padrões de Referência , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
10.
Br J Cancer ; 121(10): 869-876, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31551580

RESUMO

BACKGROUND: Type 2 diabetes mellitus and high total cholesterol and triglycerides are known to be associated with increased colorectal cancer risk for the general population. These associations are unknown for people with a germline DNA mismatch repair gene mutation (Lynch syndrome), who are at high risk of colorectal cancer. METHODS: This study included 2023 (56.4% female) carriers with a mismatch repair gene mutation (737 in MLH1, 928 in MSH2, 230 in MSH6, 106 in PMS2, 22 in EPCAM) recruited by the Colon Cancer Family Registry between 1998 and 2012. Weighted Cox regression was used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for the associations between self-reported type 2 diabetes, high cholesterol, triglyceride and colorectal cancer risk. RESULTS: Overall, 802 carriers were diagnosed with colorectal cancer at a median age of 42 years. A higher risk of colorectal cancer was observed in those with self-reported type-2 diabetes (HR 1.92; 95% CI, 1.03-3.58) and high cholesterol (HR 1.76; CI 1.23-2.52) compared with those without these conditions. There was no evidence of high triglyceride being associated with colorectal cancer risk. CONCLUSION: For people with Lynch syndrome, self-reported type-2 diabetes mellitus and high cholesterol were associated with increased colorectal cancer risk.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Predisposição Genética para Doença , Adulto , Idoso , Idoso de 80 Anos ou mais , Colesterol/sangue , Neoplasias Colorretais/sangue , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/genética , Neoplasias Colorretais Hereditárias sem Polipose/sangue , Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/genética , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Molécula de Adesão da Célula Epitelial/genética , Feminino , Mutação em Linhagem Germinativa/genética , Humanos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Modelos de Riscos Proporcionais , Fatores de Risco , Triglicerídeos/sangue
11.
Mod Pathol ; 32(12): 1814-1822, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31273317

RESUMO

Most patients with Cowden syndrome have lesions in the gastrointestinal tract, characterized by multiple polyps of various histologic types in the large bowel, polyps in the upper gastrointestinal tract, and esophageal glycogenic acanthosis. However, pathologists are often unaware of the distinctive polyposis phenotype of Cowden syndrome. In this multicenter study, we report the spectrum of gastrointestinal manifestations in a series of 43 Cowden syndrome patients who had at least one endoscopy. The median age at the first endoscopy was 46 years and 58% were women. In 24 of 29 (83%) tested patients, a pathogenic germline mutation in PTEN was identified. The histology from 199 endoscopy procedures (67 upper gastrointestinal endoscopy and 132 colonoscopies) was reviewed. Hamartomatous polyps of the large bowel were the most common lesions, present in 85% of patients. Hamartomatous polyps showed varied histology, including lymphoid aggregates in 55% of patients, a lipomatous component in 52%, a ganglioneuromatous component in 52%, and a fibrous-rich component in 14%. Polyps with at least two different stromal components were found in 55% of patients. Inflammatory polyps were present in 21% of patients. Conventional adenomas and serrated polyps were identified in 48% and 62% of patients, respectively. In the upper gastrointestinal tract, the most common lesions were esophageal glycogenic acanthosis (37%), gastric hamartomatous polyps (47%), and duodenal hamartomatous polyps (20%). All patients with glycogenic acanthosis who had a colonoscopy had hamartomatous polyps of the large bowel. In five patients, the diagnosis of Cowden syndrome was established after the pathology report raised suspicion for the diagnosis. Pathologists who are aware of the characteristic admixture of lesions in Cowden syndrome can play an essential role in recommending referral to genetic counseling and gene testing. Early diagnosis of Cowden syndrome is important, as these patients and their relatives are at increased risk for developing multiple cancers.


Assuntos
Trato Gastrointestinal/patologia , Síndrome do Hamartoma Múltiplo/patologia , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Pólipos Intestinais/etiologia , Pólipos Intestinais/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
12.
Fam Cancer ; 18(4): 389-397, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31209717

RESUMO

Before SNP-based risk can be incorporated in colorectal cancer (CRC) screening, the ability of these SNPs to estimate CRC risk for persons with and without a family history of CRC, and the screening implications need to be determined. We estimated the association with CRC of a 45 SNP-based risk using 1181 cases and 999 controls, and its correlation with CRC risk predicted from detailed family history. We estimated the predicted change in the distribution across predefined risk categories, and implications for recommended screening commencement age, from adding SNP-based risk to family history. The inter-quintile risk ratio for colorectal cancer risk of the SNP-based risk was 3.28 (95% CI 2.54-4.22). SNP-based and family history-based risks were not correlated (r = 0.02). For persons with no first-degree relatives with CRC, screening could commence 4 years earlier for women (5 years for men) in the highest quintile of SNP-based risk. For persons with two first-degree relatives with CRC, screening could commence 16 years earlier for men and women in the highest quintile, and 7 years earlier for the lowest quintile. This 45 SNP panel in conjunction with family history, can identify people who could benefit from earlier screening. Risk reclassification by 45 SNPs could inform targeted screening for CRC prevention, particularly in clinical genetics settings when mutations in high-risk genes cannot be identified. Yet to be determined is cost-effectiveness, resources requirements, community, patient and clinician acceptance, and feasibility with potentially ethical, legal and insurance implications.


Assuntos
Neoplasias Colorretais/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Estudos de Casos e Controles , Neoplasias Colorretais/prevenção & controle , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Programas de Rastreamento , Anamnese , Pessoa de Meia-Idade , Razão de Chances
13.
Mod Pathol ; 32(10): 1390-1415, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31028362

RESUMO

Our understanding of serrated colorectal polyps has increased dramatically over the past two decades and has led to a modern classification scheme for these lesions. Sessile serrated polyps with dysplasia represent the most clinically significant serrated polyp; however, the morphologic heterogeneity of dysplasia in sessile serrated polyps has only recently been recognized and correlated with MLH1 immunohistochemistry. Detailed morphologic analysis of traditional serrated adenomas has led to the recognition of flat and early forms of this polyp. Robust data on the risk of metachronous lesions in patients with serrated polyps are also beginning to emerge. This review will summarize our current understanding of serrated polyps and associated carcinomas with a focus on diagnostic criteria, morphologic heterogeneity, molecular findings, and natural history. Controversial issues in the diagnosis and classification of these polyps are also discussed.


Assuntos
Adenoma/patologia , Pólipos do Colo/patologia , Neoplasias Colorretais/patologia , Adenoma/metabolismo , Pólipos do Colo/metabolismo , Neoplasias Colorretais/metabolismo , Humanos , Imuno-Histoquímica , Proteína 1 Homóloga a MutL/metabolismo , Patologia Molecular
14.
Pathology ; 51(3): 233-239, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30851981

RESUMO

Lynch syndrome is the most common hereditary form of colorectal carcinoma caused by a constitutional pathogenic mutation in a DNA mismatch repair gene. Identifying Lynch syndrome is essential to initiate intensive surveillance program for the patient and affected relatives. On behalf of the Australasian Gastrointestinal Pathology Society (AGPS), we present in this manuscript consensus guidelines for Lynch syndrome screening in patients with colorectal carcinoma. The goal of this consensus document is to provide recommendations to pathologists for diagnosis of Lynch syndrome with discussion of the benefits and limitations of each test. Universal screening for defective mismatch repair is recommended, in agreement with the recent endorsement of universal testing by the National Health and Medical Research Council in Australia and the New Zealand Ministry of Health. The value of evaluating defective mismatch repair is acknowledged not only for Lynch syndrome screening but also for therapeutic decision information in patient management. AGPS advocates appropriate government funding for the molecular tests necessary for Lynch syndrome screening (BRAF mutation, MLH1 methylation testing).


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA , Síndromes Neoplásicas Hereditárias/diagnóstico , Austrália , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Detecção Precoce de Câncer , Humanos , Instabilidade de Microssatélites , Mutação , Nova Zelândia
15.
Histopathology ; 75(1): 81-87, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30825335

RESUMO

AIMS: Sessile serrated lesions (SSL) with dysplasia are uncommon polyps with a high risk of rapid malignant transformation. Most of these lesions have a BRAF mutation and 75% show loss of MLH1 expression in their dysplastic component. Different morphological patterns of dysplasia occurring in these polyps have recently been described. We hypothesised that a subset of SSLs with dysplasia mimicking the dysplasia seen in conventional adenoma (adenomatous dysplasia) may represent a collision lesion between an ordinary SSL and a conventional adenoma. METHODS AND RESULTS: We selected 80 SSLs with dysplasia, including 19 with adenomatous dysplasia, 18 with serrated dysplasia and 43 with dysplasia not otherwise specified (NOS). BRAF mutation analysis was performed using molecular testing (allelic discrimination) and the mutation-specific BRAF-V600E immunohistochemistry (clone VE1). The overall BRAF-V600E mutation rate was 84% in all lesions, 68% in SSLs with adenomatous dysplasia, 89% in SSLs with serrated dysplasia and 88% in SSLs with dysplasia NOS. From the 63 SSLs with dysplasia that were positive for the BRAF-V600E mutation, a negative BRAF-V600E immunostaining was observed in the dysplastic component of 83% of SSLs with adenomatous dysplasia, 0% of SSLs with serrated dysplasia and 3% of SSLs with dysplasia NOS (P < 0.001). CONCLUSIONS: These findings suggest that SSLs with adenomatous dysplasia may not represent advanced SSLs, but instead may be a collision between a non-dysplastic SSL and a conventional adenoma.


Assuntos
Adenoma/genética , Adenoma/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Pólipos Intestinais/genética , Pólipos Intestinais/patologia , Proteínas Mutantes/genética , Proteínas Proto-Oncogênicas B-raf/genética , Adenoma/metabolismo , Pólipos Adenomatosos/genética , Pólipos Adenomatosos/metabolismo , Pólipos Adenomatosos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Neoplasias Colorretais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Pólipos Intestinais/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas Mutantes/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Estudos Retrospectivos
17.
J Clin Gastroenterol ; 53(3): e113-e116, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-29570172

RESUMO

GOALS: To provide preliminary evidence that sessile serrated adenomas (SSA) are low-risk polyps in young patients. BACKGROUND: SSAs are the dominant polyp of the serrated neoplasia pathway and as such are the precursor of up to 20% of colorectal carcinomas (CRC). Up to 90% of these cancers are expected to harbor a BRAF mutation. SSAs are being diagnosed with increasing frequency in young patients, placing a significant burden on colonoscopic services. Evidence to direct the surveillance intervals for these young patients is not available. STUDY: We utilized 2 patient cohorts comprising (1) a consecutive series of patients who underwent outpatient colonoscopy through a tertiary hospital and (2) a consecutive series of resection specimens for CRC processed through a gastrointestinal pathology service. The prevalence of SSAs by age was determined in the patients undergoing colonoscopy and compared with the ages of patients with BRAF mutated CRC in the pathology series. RESULTS: The prevalence of SSAs was similar irrespective of age. By comparison, BRAF mutated CRCs were very rare (3.8% of cases) in patients younger than 50 years of age and uncommon (9.3% of cases) in patients younger than 60 years of age, but increased to 39.8% in patients older than 80 years of age. CONCLUSIONS: These results suggest that SSAs develop at a young age, but have a prolonged dwell time and are unlikely to develop into cancer in patients younger than 60 years of age. These findings highlight the need for further targeted research to determine the most appropriate surveillance intervals for young patients with sporadic SSAs.


Assuntos
Adenoma/patologia , Pólipos do Colo/patologia , Neoplasias Colorretais/patologia , Proteínas Proto-Oncogênicas B-raf/genética , Adenoma/epidemiologia , Adenoma/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Pólipos do Colo/epidemiologia , Pólipos do Colo/genética , Colonoscopia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/genética , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Prevalência , Estudos Retrospectivos , Fatores de Tempo
18.
J Clin Oncol ; 36(29): 2961-2968, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30161022

RESUMO

PURPOSE: Lynch syndrome due to pathogenic variants in the DNA mismatch repair genes MLH1, MSH2, and MSH6 is predominantly associated with colorectal and endometrial cancer, although extracolonic cancers have been described within the Lynch tumor spectrum. However, the age-specific cumulative risk (penetrance) of these cancers is still poorly defined for PMS2-associated Lynch syndrome. Using a large data set from a worldwide collaboration, our aim was to determine accurate penetrance measures of cancers for carriers of heterozygous pathogenic PMS2 variants. METHODS: A modified segregation analysis was conducted that incorporated both genotyped and nongenotyped relatives, with conditioning for ascertainment to estimates corrected for bias. Hazard ratios (HRs) and corresponding 95% CIs were estimated for each cancer site for mutation carriers compared with the general population, followed by estimation of penetrance. RESULTS: In total, 284 families consisting of 4,878 first- and second-degree family members were included in the analysis. PMS2 mutation carriers were at increased risk for colorectal cancer (cumulative risk to age 80 years of 13% [95% CI, 7.9% to 22%] for males and 12% [95% CI, 6.7% to 21%] for females) and endometrial cancer (13% [95% CI, 7.0%-24%]), compared with the general population (6.6%, 4.7%, and 2.4%, respectively). There was no clear evidence of an increased risk of ovarian, gastric, hepatobiliary, bladder, renal, brain, breast, prostate, or small bowel cancer. CONCLUSION: Heterozygous PMS2 mutation carriers were at small increased risk for colorectal and endometrial cancer but not for any other Lynch syndrome-associated cancer. This finding justifies that PMS2-specific screening protocols could be restricted to colonoscopies. The role of risk-reducing hysterectomy and bilateral salpingo-oophorectomy for PMS2 mutation carriers needs further discussion.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Neoplasias/epidemiologia , Neoplasias/genética , Penetrância , Adulto , Idoso , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação
19.
Histopathology ; 73(6): 1023-1029, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30007084

RESUMO

AIMS: Traditional serrated adenoma (TSA) is the least common subtype of serrated colorectal polyp. Large protuberant lesions are easily recognised; however, the origins of TSAs are not known, and early forms have not been described. Some large TSAs present with a flat 'shoulder' component surrounding the central protuberant component. We hypothesised that small polyps with the same histology as these shoulder regions may represent early TSAs. Thus the primary aim of the study is to describe the histology of these presumptive early TSAs. METHODS AND RESULTS: We collected 70 small (<10 mm) polyps that may represent early TSAs on the basis of typical TSA cytology covering the luminal surface. We also identified 12 large TSAs with a shoulder component resembling these small polyps. The study polyp patients had a mean age of 58 years, and 54% were female; the polyps had a mean diameter of 4.1 mm and were predominantly distal (71%). Morphologically, slit-like serrations were present in 81%, ectopic crypt formations were present in 67%, and a villous component was present in 47%. These histological features were similar to those of the 12 shoulder lesions. Immunohistochemical stains showed an absence of ß-catenin nuclear expression in 96% of the small polyps, retained expression of MLH1 in 100%, and Ki67 positivity restricted to the crypt bases and ectopic crypt formations. BRAF and KRAS mutations were identified in 47% and 31% of the polyps, respectively. BRAF-mutated polyps were more likely than KRAS-mutated polyps to arise in a precursor polyp (82% versus 18%, P < 0.001), and were more likely to have slit-like serrations (100% versus 73%, P = 0.003). CONCLUSIONS: These morphological, immunohistochemical and molecular findings are similar to what has been reported in large TSAs, and support the hypothesis that these polyps represent early forms of TSA.


Assuntos
Adenoma/patologia , Neoplasias do Colo/patologia , Pólipos do Colo/patologia , Adenoma/metabolismo , Biomarcadores Tumorais , Neoplasias do Colo/metabolismo , Pólipos do Colo/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo
20.
Mod Pathol ; 31(10): 1608-1618, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29884888

RESUMO

Lynch syndrome is the most common form of hereditary colorectal carcinoma. However, establishing the diagnosis of Lynch syndrome is challenging, and ancillary studies that distinguish between sporadic DNA mismatch repair (MMR) protein deficiency and Lynch syndrome are needed, particularly when germline mutation studies are inconclusive. The aim of this study was to determine if MMR protein-deficient non-neoplastic intestinal crypts can help distinguish between patients with and without Lynch syndrome. We evaluated the expression of MMR proteins in non-neoplastic intestinal mucosa obtained from colorectal surgical resection specimens from patients with Lynch syndrome-associated colorectal carcinoma (n = 52) and patients with colorectal carcinoma without evidence of Lynch syndrome (n = 70), including sporadic MMR protein-deficient colorectal carcinoma (n = 30), MMR protein proficient colorectal carcinoma (n = 30), and "Lynch-like" syndrome (n = 10). MMR protein-deficient non-neoplastic colonic crypts were identified in 19 of 122 (16%) patients. MMR protein-deficient colonic crypts were identified in 18 of 52 (35%) patients with Lynch syndrome compared to only 1 of 70 (1%) patients without Lynch syndrome (p < 0.001). This one patient had "Lynch-like" syndrome and harbored two MSH2-deficient non-neoplastic colonic crypts. MMR protein-deficient non-neoplastic colonic crypts were not identified in patients with sporadic MMR protein-deficient or MMR protein proficient colorectal carcinoma. Our findings suggest that MMR protein-deficient colonic crypts are a novel indicator of Lynch syndrome, and evaluation for MMR protein-deficient crypts may be a helpful addition to Lynch syndrome diagnostics.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Reparo de Erro de Pareamento de DNA/genética , Mucosa Intestinal , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais Hereditárias sem Polipose/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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