Transcriptional regulation of chemokine network by biologic monotherapy in ileum of patients with Crohn's disease.

BACKGROUND: Crohn's disease (CD) exacerbation is marked by an intense cellular trafficking. We set out to determine the specific impact of biologic therapies on regulating chemokine network gene expression in healthy, mildly and severely inflamed tissue of CD patients. METHODS: Twenty CD patients on biologics (adalimumab, ustekinumab, vedolizumab) or untreated undergoing colonoscopy due to clinical symptoms of flare. Healthy, mildly and severely inflamed ileum biopsies from each patient were collected. Chemokines and receptors gene expression was analyzed and a STRING analysis for functional enrichment was performed. RESULTS: The chemokine network exhibited wide transcriptional differences among tissues in active untreated patients, whereas all biologic treatments reduced these differences and homogenized their transcriptional activity. In mildly inflamed tissue, all treatments showed gene upregulation while ustekinumab additionally maintained the downregulation of genes such as CCL2, CCL3, CCL17 or CCL23, involved in T cell chemotaxis, inflammatory monocyte and NK trafficking. In severely inflamed tissue, all treatments shared a downregulatory effect on chemokines controlling T cell response (i.e. CXCL16, CXCR3). Adalimumab and vedolizumab significantly reduced the expression of genes promoting antigen presentation by DCs and the initiation of leukocyte extravasation (i.e. CXCL12, CCL25, CCR7). Ustekinumab significantly reduced genes positively regulating Th1 cytokine production and IL-8 mediated signaling (i.e. IL1B, XCL1, CXCR1, CXCR2). CONCLUSION: Biologic therapies differentially target the chemokine network gene expression profile in the ileal tissue of active CD patients. These results may contribute to better understanding cell homing and to defining future personalized therapeutic strategies for CD patients.

xDEEP-MSI: Explainable Bias-Rejecting Microsatellite Instability Deep Learning System in Colorectal Cancer.

The prediction of microsatellite instability (MSI) using deep learning (DL) techniques could have significant benefits, including reducing cost and increasing MSI testing of colorectal cancer (CRC) patients. Nonetheless, batch effects or systematic biases are not well characterized in digital histology models and lead to overoptimistic estimates of model performance. Methods to not only palliate but to directly abrogate biases are needed. We present a multiple bias rejecting DL system based on adversarial networks for the prediction of MSI in CRC from tissue microarrays (TMAs), trained and validated in 1788 patients from EPICOLON and HGUA. The system consists of an end-to-end image preprocessing module that tile samples at multiple magnifications and a tissue classification module linked to the bias-rejecting MSI predictor. We detected three biases associated with the learned representations of a baseline model: the project of origin of samples, the patient's spot and the TMA glass where each spot was placed. The system was trained to directly avoid learning the batch effects of those variables. The learned features from the bias-ablated model achieved maximum discriminative power with respect to the task and minimal statistical mean dependence with the biases. The impact of different magnifications, types of tissues and the model performance at tile vs patient level is analyzed. The AUC at tile level, and including all three selected tissues (tumor epithelium, mucin and lymphocytic regions) and 4 magnifications, was 0.87 ± 0.03 and increased to 0.9 ± 0.03 at patient level. To the best of our knowledge, this is the first work that incorporates a multiple bias ablation technique at the DL architecture in digital pathology, and the first using TMAs for the MSI prediction task.

Effects of Somatic Methylation in Colonic Polyps on Risk of Developing Metachronous Advanced Colorectal Lesions.

The utility of molecular markers for predicting the risk of metachronous advanced colorectal lesions (MACLs) remains poorly investigated. We examined the relationship between somatic hypermethylation in polyps at baseline and the risk of developing MACL. This retrospective cohort study included 281 consecutive patients with colonic polyps who were enrolled between 2007 and 2009 and followed-up until 2014. MACLs were defined as adenomas of ≥10 mm, high-grade dysplasia, or with a villous component; and serrated lesions of ≥10 mm or with dysplasia. In total, 595 polyps were removed at baseline colonoscopy and analyzed for pathological characteristics and CpG island methylator phenotype (CIMP) using the MS-MLPA (Methylation-Specific -- Multiplex Ligation-dependent Probe Amplification) technique. Forty-five patients (16.0%) showed at least one CIMP+ polyp. MACL risk was higher in patients with CIMP+ polyps (odds ratio (OR), 4.50; 95% CI, 1.78-11.4; p = 0.002). Patients with CIMP+ polyps also exhibited shorter time to MACL development (33.8 months vs. 50.1 months; p < 0.001), even with adjustment for polyp size and number (OR, 2.40; 95% CI, 1.33-4.34). Adding CIMP analysis improved the sensitivity (57.0% to 70.9%), negative predictive value (71.1% to 77.3%), and overall accuracy (49.8% to 52.0%) for MACL risk estimation. These results highlight that CIMP may be a useful marker for endoscopic surveillance.

A Very Rare Case of Right Insular Lobe Langerhans Cell Histiocytosis (CD1a+) Mimicking Glioblastoma Multiforme in a Young Adult.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a multisystemic dendritic cell proliferation that is relatively uncommon in adults. Central nervous system LCH outside the pituitary gland is even more uncommon. CASE DESCRIPTION: We report the case of a 42-year-old man who had complained of right-side hemicranial pain and left arm minor paresis. The symptoms were due to a right insular lobe heterogeneous-enhancing lesion associated with extensive vasogenic edema. The first diagnostic impression suggested glioblastoma multiforme or localized metastasis. The thoracic, abdominal, pelvic computed tomography scan only detected small upper lung inactive nodules suggesting silent focal LCH. A very hard lesion was almost completely removed through a pterional craniotomy approach, with no fluorescence after aminolevulinic acid infusion. The intraoperative biopsy findings ruled out glioma but could not confirm lymphoma. The definitive cerebral biopsy findings showed lymphocytes and histiocytes (CD1a+, S-1001+), with a diagnosis of intracerebral parenchymal LCH. Fractioned radiotherapy resulted in clinical and radiological remission. CONCLUSIONS: The present case is so rare it should not be used as a guide. We probably will never see a single intraparenchymal supratentorial central nervous system LCH lesion. However, we hope our report will help colleagues in the future with the thought process.

KRAS and BRAF somatic mutations in colonic polyps and the risk of metachronous neoplasia.

BACKGROUND & AIMS: High-risk features of colonic polyps are based on size, number, and pathologic characteristics. Surveillance colonoscopy is often recommended according to these findings. This study aimed to determine whether the molecular characteristics of polyps might provide information about the risk of metachronous advanced neoplasia. METHODOLOGY: We retrospectively included 308 patients with colonic polyps. A total of 995 polyps were collected and tested for somatic BRAF and KRAS mutations. Patients were classified into 3 subgroups, based on the polyp mutational profile at baseline, as follows: non-mutated polyps (Wild-type), at least one BRAF-mutated polyp, or at least one KRAS-mutated polyp. At surveillance, advanced adenomas were defined as adenomas ≥ 10 mm and/or with high grade dysplasia or a villous component. In contrast, advanced serrated polyps were defined as serrated polyps ≥ 10 mm in any location, located proximal to the splenic flexure with any size or with dysplasia. RESULTS: At baseline, 289 patients could be classified as wild-type (62.3%), BRAF mutated (14.9%), or KRAS mutated (22.8%). In the univariate analysis, KRAS mutations were associated with the development of metachronous advanced polyps (OR: 2.36, 95% CI: 1.22-4.58; P = 0.011), and specifically, advanced adenomas (OR: 2.42, 95% CI: 1.13-5.21; P = 0.023). The multivariate analysis, adjusted for age and sex, also showed associations with the development of metachronous advanced polyps (OR: 2.27, 95% CI: 1.15-4.46) and advanced adenomas (OR: 2.23, 95% CI: 1.02-4.85). CONCLUSIONS: Our results suggested that somatic KRAS mutations in polyps represent a potential molecular marker for the risk of developing advanced neoplasia.

Increased Risk of Colorectal Cancer in Patients With Multiple Serrated Polyps and Their First-Degree Relatives.

BACKGROUND & AIMS: We investigated whether patients with multiple serrated polyps, but not meeting the World Health Organization criteria for serrated polyposis syndrome, and their relatives have similar risks for colorectal cancer (CRC) as those diagnosed with serrated polyposis. METHODS: We collected data from patients with more than 10 colonic polyps, recruited in 2008-2009 from 24 hospitals in Spain for a study of causes of multiple colonic polyps. We analyzed data from 53 patients who met the criteria for serrated polyposis and 145 patients who did not meet these criteria, but who had more than 10 polyps throughout the colon, of which more than 50% were serrated. We calculated age- and sex-adjusted standardized incidence ratios (SIRs) for CRC in both groups, as well as in their first-degree relatives. RESULTS: The prevalence of CRC was similar between patients with confirmed serrated polyposis and multiple serrated polyps (odds ratio, 1.35; 95% confidence interval [CI], 0.64-2.82; P = .40). The SIR for CRC in patients with serrated polyposis (0.51; 95% CI, 0.01-2.82) did not differ significantly from the SIR for CRC in patients with multiple serrated polyps (0.74; 95% CI, 0.20-1.90; P = .70). The SIR for CRC also did not differ significantly between first-degree relatives of these groups (serrated polyposis: 3.28, 95% CI, 2.16-4.77; multiple serrated polyps: 2.79, 95% CI, 2.10-3.63; P = .50). Kaplan-Meier analysis showed no differences in the incidence of CRC between groups during the follow-up period (log-rank, 0.6). CONCLUSIONS: The risk of CRC in patients with multiple serrated polyps who do not meet the criteria for serrated polyposis, and in their first-degree relatives, is similar to that of patients diagnosed with serrated polyposis.

Hiperplasia nodular regenerativa hepática asociada a inmunodeficiencia común variable y a otras comorbilidades / Nodular regenerative hyperplasia associated with common variable immunodeficiency and other comorbidities

Fundamento y objetivo: Actualmente no se dispone de muchos datos sobre la evolución de la hiperplasia nodular regenerativa (HNR) asociada o no a enfermedades de base, y en concreto de la asociada a inmunodeficiencia común variable (IDCV). Se presentan 20 casos de HNR y se analizan las diferencias entre los casos asociados a IDCV y los relacionados con otras enfermedades. Métodos: Estudio retrospectivo y descriptivo durante un período de 14 años. Resultados: De los 20 pacientes, 12 eran hombres; la mediana de edad fue de 51 años. La IDCV fue la principal enfermedad asociada con HNR. En los pacientes con IDCV y HNR la hemorragia gastrointestinal fue más común, todos tenían elevación de FA y GGT y ninguno tenía valores de albúmina y bilirrubina alterados comparados con los pacientes sin IDCV. De los pacientes con HNR en seguimiento han fallecido el 50% de los asociados a IDCV (2/4) frente al 33,3% (5/15) sin IDCV. Conclusiones: La HNR en los pacientes con IDCV parece manifestarse más con datos bioquímicos de colestasis anictérica e hipertensión portal y podría asociar una supervivencia menor (AU)

Background and objective: Currently, there are not many data on the evolution of nodular regenerative hyperplasia (NRH) associated or not with underlying diseases and in particular that associated with common variable inmunodeficiency (CVID). Twenty cases of NRH are presented, and the differences between the cases associated with CVID and those related to other diseases are analysed. Methods: Retrospective and descriptive study over a period of 14 years. Results: Twelve out of the 20 patients were men; the median age was 51 years. CVID was the main illness associated with NRH. In patients with CVID and NRH, gastrointestinal haemorrhage was more common, all the patients had high gamma glutamyl transferase and alkaline phosphatase and none had altered albumin and bilirubin levels compared to the patients without CVID. On follow-up, 50% of patients with CVID (2/4) had died compared to 33.3% (5/15) without CVID. Conclusions: NRH in patients with CVID seems to have more biochemical data of anicteric cholestasis and portal hypertension and could be associated with lower survival (AU)

[Nodular regenerative hyperplasia associated with common variable immunodeficiency and other comorbidities]. / Hiperplasia nodular regenerativa hepática asociada a inmunodeficiencia común variable y a otras comorbilidades.

BACKGROUND AND OBJECTIVE: Currently, there are not many data on the evolution of nodular regenerative hyperplasia (NRH) associated or not with underlying diseases and in particular that associated with common variable inmunodeficiency (CVID). Twenty cases of NRH are presented, and the differences between the cases associated with CVID and those related to other diseases are analysed. METHODS: Retrospective and descriptive study over a period of 14 years. RESULTS: Twelve out of the 20 patients were men; the median age was 51 years. CVID was the main illness associated with NRH. In patients with CVID and NRH, gastrointestinal haemorrhage was more common, all the patients had high gamma glutamyl transferase and alkaline phosphatase and none had altered albumin and bilirubin levels compared to the patients without CVID. On follow-up, 50% of patients with CVID (2/4) had died compared to 33.3% (5/15) without CVID. CONCLUSIONS: NRH in patients with CVID seems to have more biochemical data of anicteric cholestasis and portal hypertension and could be associated with lower survival.

Endoscopic surveillance in patients with multiple (10-100) colorectal polyps.

BACKGROUND AND STUDY AIMS: Endoscopic surveillance in patients with multiple colorectal polyps aims to reduce colorectal cancer (CRC) incidence and mortality, as well as the need for colorectal surgery. The aim of this study was to determine the risk of developing CRC or the need for surgery during endoscopic surveillance in a cohort of patients with multiple (10 - 100) colorectal polyps. PATIENTS AND METHODS: This was a multicentrer, longitudinal, observational study in 15 CRC high risk clinics in Spain, carried out between January 2009 and December 2010. Patients who were included in the EPIPOLIP trial and had at least 1 year of follow-up were included in the study. The primary outcome of interest was the incidence of CRC at least 1 year following the initial colonoscopy. The secondary outcome was the need for colorectal surgery. RESULTS: A total of 265 patients were followed for a median of 3.8 years. Patients underwent a median of 5 colonoscopies, and 17 patients (6.4 %) were diagnosed with CRC. A total of 32 patients (12.1 %) underwent surgery, including 15 (5.7 %) for prophylaxis without a diagnosis of CRC. The corresponding incidence density rates for CRC and colorectal surgery were 1.4 (95 % confidence interval [CI] 0.7 to 2.1) and 2.7 (95 %CI 1.7 to 3.6) per 100 patient-years, respectively. Only the presence of symptoms at first colonoscopy was independently associated with CRC diagnosis (hazard ratio [HR] 7.7, 95 %CI 1.1 to 59.3) and colorectal surgery (HR 4.6, 95 %CI 1.02 to 20.6). CONCLUSIONS: Patients with more than 10 neoplastic polyps required frequent colonoscopies within a short follow-up period. More than 10 % of patients required colorectal surgery within 4 years, more than half for incident CRC.

Prevalence of MLH1 constitutional epimutations as a cause of Lynch syndrome in unselected versus selected consecutive series of patients with colorectal cancer.

BACKGROUND: The prevalence of MLH1 constitutional epimutations in the general population is unknown. We sought to analyse the prevalence of MLH1 constitutional epimutations in unselected and selected series of patients with colorectal cancer (CRC). METHODS: Patients with diagnoses of CRC (n=2123) were included in the unselected group. For comparison, a group of 847 selected patients with CRC who fulfilled the revised Bethesda guidelines (rBG) were also included. Somatic and constitutional MLH1 methylation was assayed via methylation-specific multiplex ligation-dependent probe amplification of cases lacking MLH1 expression. Germline alterations in mismatch-repair (MMR) genes were assessed via Sanger sequencing and methylation-specific multiplex ligation-dependent probe amplification. RESULTS: Loss of MLH1 expression occurred in 5.5% of the unselected series and 12.5% of the selected series (p<0.0001). No constitutional epimutations in MLH1 were detected in the unselected population (0/62); five cases from the selected series were positive for MLH1 epimutations (15.6%, 5/32; p=0.004). CONCLUSIONS: Our results suggest a negligible prevalence of MLH1 constitutional epimutations in unselected cases of CRC. Therefore, MLH1 constitutional epimutation analysis should be conducted only for patients who fulfil the rBG and who lack MLH1 expression with methylated MLH1.

Paniculitis mesentérica colónica / Mesenteric panniculitis of the colon

No disponible

Prevalence and characteristics of MUTYH-associated polyposis in patients with multiple adenomatous and serrated polyps.

PURPOSE: The present study aimed to determine the prevalence of MUTYH mutations in patients with multiple colonic polyps and to explore the best strategy for diagnosing MUTYH-associated polyposis (MAP) in these patients. EXPERIMENTAL DESIGN: This study included 405 patients with at least 10 colonic polyps each. All cases were genetically tested for the three most frequent MUTYH mutations. Whole-gene analysis was performed in heterozygous patients and in 216 patients lacking the three most frequent mutations. Polyps from 56 patients were analyzed for the KRAS-Gly12Cys and BRAF V600E somatic mutations. RESULTS: Twenty-seven (6.7%) patients were diagnosed with MAP, of which 40.8% showed serrated polyps. The sensitivity of studying only the three common variants was 74.1%. Of 216 patients without any monoallelic mutation in common variants, whole-gene analysis revealed biallelic pathogenic mutation in only one. G396D mutation was associated with serrated lesions and older age at diagnosis. There was a strong association between germinal MUTYH mutation and KRAS Gly12Cys somatic mutation in polyps. BRAF V600E mutation was found in 74% of serrated polyps in MUTYH-negative patients and in none of the polyps of MAP patients. CONCLUSIONS: We observed a low frequency of MUTYH mutations among patients with multiple adenomatous and serrated polyps. The MAP phenotype frequently included patients with serrated polyps, especially when G396D mutation was involved. Our results show that somatic molecular markers of polyps can be useful in identifying MAP cases and support the need for the complete MUTYH gene analysis only in patients heterozygous for recurrent variants.

Prevalence of Lynch syndrome among patients with newly diagnosed endometrial cancers.

BACKGROUND: Lynch syndrome (LS) is a hereditary condition that increases the risk for endometrial and other cancers. The identification of endometrial cancer (EC) patients with LS has the potential to influence life-saving interventions. We aimed to study the prevalence of LS among EC patients in our population. METHODS: Universal screening for LS was applied for a consecutive series EC. Tumor testing using microsatellite instability (MSI), immunohistochemistry (IHC) for mismatch-repair (MMR) protein expression and MLH1-methylation analysis, when required, was used to select LS-suspicious cases. Sequencing of corresponding MMR genes was performed. RESULTS: One hundred and seventy-three EC (average age, 63 years) were screened. Sixty-one patients (35%) had abnormal IHC or MSI results. After MLH1 methylation analysis, 27 cases were considered suspicious of LS. From these, 22 were contacted and referred for genetic counseling. Nineteen pursued genetic testing and eight were diagnosed of LS. Mutations were more frequent in younger patients (<50 yrs). Three cases had either intact IHC or MSS and reinforce the need of implement the EC screening with both techniques. CONCLUSION: The prevalence of LS among EC patients was 4.6% (8/173); with a predictive frequency of 6.6% in the Spanish population. Universal screening of EC for LS is recommended.

Clinical subtypes and molecular characteristics of serrated polyposis syndrome.

BACKGROUND & AIMS: We investigated clinical and molecular differences between the different phenotypes of serrated polyposis syndrome (SPS) and the frequency of mutations in BRAF or KRAS in polyps from patients with SPS. METHODS: We collected data on clinical and demographic characteristics of 50 patients who fulfilled the criteria for SPS. Polymerase chain reaction and sequence analysis were used to identify BRAF and KRAS mutations in 432 polyps collected from 37 patients; we analyzed CpG island methylator phenotypes in 272 of these polyps. RESULTS: Fifteen patients (30%) had type 1 SPS and 35 had type 2 SPS. There were no significant differences in age at diagnosis, sex, smoking frequency, body mass index, or colorectal cancer predisposition between groups of patients, or in the pathologic or molecular characteristics of their polyps. A familial history of colorectal cancer or colonic polyps was reported more frequently by patients with type 2 SPS. BRAF mutations were found in 63% of polyps and KRAS mutations were found in 9.9%; 43.4% of polyps had the CpG island methylator phenotype-high phenotype. A per-patient analysis revealed that all patients had a BRAF or KRAS mutation in more than 25% of their polyps; 84.8% of patients had a mutation in BRAF or KRAS in more than 50% of their polyps. CONCLUSIONS: Except for a greater likelihood of familial history of colorectal cancer or colonic polyps in patients with type 2 SPS, we found no significant demographic, pathologic, or molecular differences between types 1 and 2 SPS. All patients had a BRAF or KRAS mutation in at least 25% of their polyps.

Risk of cancer in cases of suspected lynch syndrome without germline mutation.

BACKGROUND & AIMS: Colorectal cancers (CRCs) with microsatellite instability (MSI) and a mismatch repair (MMR) immunohistochemical deficit without hypermethylation of the MLH1 promoter are likely to be caused by Lynch syndrome. Some patients with these cancers have not been found to have pathogenic germline mutations and are considered to have Lynch-like syndrome (LLS). The aim of this study was to determine the risk of cancer in families of patients with LLS. METHODS: We studied a population-based cohort of 1705 consecutive patients, performing MSI tests and immunohistochemical analyses of MMR proteins. Patients were diagnosed with Lynch syndrome when they were found to have pathogenic germline mutations. Patients with MSI and loss of MSH2 and/or MSH6 expression, isolated loss of PMS2 or loss of MLH1 without MLH1 promoter hypermethylation, and no pathogenic mutation were considered to have LLS. The clinical characteristics of patients and the age- and sex-adjusted standardized incidence ratios (SIRs) of cancer in families were compared between groups. RESULTS: The incidence of CRC was significantly lower in families of patients with LLS than in families with confirmed cases of Lynch syndrome (SIR for Lynch syndrome, 6.04; 95% confidence interval [CI], 3.58-9.54; SIR for LLS, 2.12; 95% CI, 1.16-3.56; P < .001). However, the incidence of CRC was higher in families of patients with LLS than in families with sporadic CRC (SIR for sporadic CRC, 0.48; 95% CI, 0.27-0.79; P < .001). CONCLUSIONS: The risk of cancer in families with LLS is lower that of families with Lynch syndrome but higher than that of families with sporadic CRC. These results confirm the need for special screening and surveillance strategies for these patients and their relatives.

Recomendación para la determinación de biomarcadores en el carcinoma colorrectal. Consenso Nacional de la Sociedad Española de Anatomía Patológica y de la Sociedad Española de Oncología Médica / Guidelines for biomarker testing in advanced colorectal carcinoma. A National Consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology

Este documento de consenso nace como una iniciativa conjunta de la Sociedad Española de Anatomía Patológica (SEAP) y de la Sociedad Española de Oncología Médica (SEOM) y propone recomendaciones diagnósticas y terapéuticas para el manejo del paciente con cáncer colorrectal (CCR) hereditario, localizado y avanzado basadas en la evidencia científica que existe en la actualidad sobre el uso de biomarcadores. Por tanto, este documento supone una oportunidad para mejorar la eficiencia de la actividad asistencial y la utilización de recursos, lo que redundará en un beneficio para estos pacientes. Con los datos disponibles en la actualidad, este grupo de expertos recomienda que en los pacientes con CCR localizado se determine la inestabilidad de microsatélites, ya que es un factor predictivo relevante para decidir el tratamiento adyuvante. Sin embargo, aunque las firmas de expresión genética ColoPrint® y Oncotype Dx® han demostrado tener valor pronóstico, no existe todavía consenso sobre su uso en la práctica clínica. En cuanto al CCR avanzado, la determinación del estado mutacional de KRAS es indispensable antes de administrar un tratamiento con anti-receptor del factor de crecimiento epidérmico (EGFR), como cetuximab y panitumumab. Sin embargo, la determinación de otros biomarcadores, como las mutaciones de BRAF, EGFR, PI3K y PTEN, no debe llevarse a cabo de forma rutinaria, ya que hoy por hoy no influye en la planificación del tratamiento. Otros aspectos importantes que incluye son los requisitos organizativos y los controles de calidad que deben existir para la adecuada determinación de estos biomarcadores, así como las implicaciones legales que se deben tener en cuenta(AU)

This consensus is a joint initiative of the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM). Based on scientific evidence of the use of biomarkers, it recommends diagnostic and treatment guidelines for the management of patients with hereditary, localised and advanced colorectal carcinoma (CRC). The aim of the consensus is to improve healthcare and the use of resources, which will result in increased patient benefit. Taking into consideration data currently available, the group of experts recommends testing for microsatellite instability in patients with localised CRC, as this is a strong predictive factor useful in deciding the choice of adjuvant treatment. However, although the ColoPrint® and Oncotype Dx® gene expression signatures have been shown to have prognostic value, no consensus yet exists as to their clinical use. For advanced CRC, it is essential to test for KRAS mutation status before administering an anti-epidermal growth factor receptor (EGFR) treatment, such as cetuximab or panitumumab. However, at present, testing for other biomarkers, such as BRAF, EGFR, PI3K and PTEN mutations, is not indicated as a routine procedure as it does not influence choice of treatment. Other important issues addressed include organisational requirements, necessary quality controls for the correct testing of these biomarkers as well as the pertinent legal implications(AU)

Guidelines for biomarker testing in colorectal carcinoma (CRC): a national consensus of the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM).

This consensus statement, conceived as a joint initiative of the Spanish Society of Pathology and the Spanish Society of Medical Oncology, makes diagnostic and treatment recommendations for the management of patients with hereditary, localised and advanced CRC based on the current scientific evidence on biomarker use. This consensus statement thus provides an opportunity to improve healthcare efficiency and resource use, which will benefit these patients. Based on the currently available data on this subject, this expert group recommends testing for microsatellite instability (MSI) in patients with localised CRC, as this is a strong predictive factor for deciding on adjuvant treatment. However, although the ColoPrint(®) and Oncotype Dx(®) gene expression signatures have been shown to have prognostic value, no consensus yet exists concerning their use in clinical practice. For advanced CRC, it is essential to test for KRAS mutation status before administering an anti-EGFR treatment, such as cetuximab or panitumumab. However, testing for other biomarkers, such as BRAF, EGFR, PI3K and PTEN mutations, should not be done routinely, because this does not influence treatment planning at the present time. Other important issues addressed include organisational requirements and the quality controls needed for proper testing of these biomarkers as well as the legal implications to be borne in mind when testing some biomarkers.

Serrated polyposis syndrome: molecular, pathological and clinical aspects.

Hyperplastic polyps have traditionally been considered not to have malignant potential. New pathological classification of serrated polyps and recent discoveries about the serrated pathway of carcinogenesis have revolutionized the concepts and revitalized the research in this area. Until recently, it has been thought that most colorectal cancers arise from conventional adenomas via the traditional tumor suppressor pathway initiated by a mutation of the APC gene, but it has been found that this pathway accounts for only approximately 70%-80% of colorectal cancer (CRC) cases. The majority of the remaining colorectal cancer cases follow an alternative pathway leading to CpG island methylator phenotype carcinoma with BRAF mutation and with or without microsatellite instability. The mechanism of carcinomas arising from this alternative pathway seems to begin with an activating mutation of the BRAF oncogene. Serrated polyposis syndrome is a relatively rare condition characterized by multiple and/or large serrated polyps of the colon. Clinical characteristics, etiology and relationship of serrated polyposis syndrome to CRC have not been clarified yet. Patients with this syndrome show a high risk of CRC and both sporadic and hereditary cases have been described. Clinical criteria have been used for diagnosis and frequent colonoscopy surveillance should be performed in order to prevent colorectal cancer. In this review, we try to gather new insights into the molecular pathogenesis of serrated polyps in order to understand their possible clinical implications and to make an approach to the management of this syndrome.