Inhibition of the Cyclin K-CDK12 complex induces DNA damage and increases the effect of androgen deprivation therapy in prostate cancer.

Androgen deprivation therapy (ADT) is the mainstay of the current first-line treatment concepts for patients with advanced prostate carcinoma (PCa). However, due to treatment failure and recurrence investigation of new targeted therapeutics is urgently needed. In this study, we investigated the suitability of the Cyclin K-CDK12 complex as a novel therapeutic approach in PCa using the new covalent CDK12/13 inhibitor THZ531. Here we show that THZ531 impairs cellular proliferation, induces apoptosis, and decreases the expression of selected DNA repair genes in PCa cell lines, which is associated with an increasing extent of DNA damage. Furthermore, combination of THZ531 and ADT leads to an increase in these anti-tumoral effects in androgen-sensitive PCa cells. The anti-proliferative and pro-apoptotic activity of THZ531 in combination with ADT was validated in an ex vivo PCa tissue culture model. In a retrospective immunohistochemical analysis of 300 clinical tissue samples we show that Cyclin K (CycK) but not CDK12 expression correlates with a more aggressive type of PCa. In conclusion, this study demonstrates the clinical relevance of the CycK-CDK12 complex as a promising target for combinational therapy with ADT in PCa and its importance as a prognostic biomarker for patients with PCa.

N-cadherin: A diagnostic marker to help discriminate primary liver carcinomas from extrahepatic carcinomas.

Distinguishing primary liver cancer (PLC), namely hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), from liver metastases is of crucial clinical importance. Histopathology remains the gold standard, but differential diagnosis may be challenging. While absent in most epithelial, the expression of the adherens junction glycoprotein N-cadherin is commonly restricted to neural and mesenchymal cells, or carcinoma cells that undergo the phenomenon of epithelial-to-mesenchymal transition (EMT). However, we recently established N- and E-cadherin expression as hallmarks of normal hepatocytes and cholangiocytes, which are also preserved in HCC and iCCA. Therefore, we hypothesized that E- and/or N-cadherin may distinguish between carcinoma derived from the liver vs carcinoma of other origins. We comprehensively evaluated E- and N-cadherin in 3359 different tumors in a multicenter study using immunohistochemistry and compared our results with previously published 882 cases of PLC, including 570 HCC and 312 iCCA. Most carcinomas showed strong positivity for E-cadherin. Strong N-cadherin positivity was present in HCC and iCCA. However, except for clear cell renal cell carcinoma (23.6% of cases) and thyroid cancer (29.2%), N-cadherin was only in some instances faintly expressed in adenocarcinomas of the gastrointestinal tract (0%-0.5%), lung (7.1%), pancreas (3.9%), gynecological organs (0%-7.4%), breast (2.2%) as well as in urothelial (9.4%) and squamous cell carcinoma (0%-5.6%). As expected, N-cadherin was detected in neuroendocrine tumors (25%-75%), malignant melanoma (46.2%) and malignant mesothelioma (41%). In conclusion, N-cadherin is a useful marker for the distinction of PLC vs liver metastases of extrahepatic carcinomas (P < .01).

The radiomorphological appearance of the invasive margin in pancreatic cancer is associated with tumor budding.

PURPOSE: Pancreatic cancer (PDAC) is characterized by infiltrative, spiculated tumor growth into the surrounding non-neoplastic tissue. Clinically, its diagnosis is often established by magnetic resonance imaging (MRI). At the invasive margin, tumor buds can be detected by histology, an established marker associated with poor prognosis in different types of tumors. METHODS: We analyzed PDAC by determining the degree of tumor spiculation on T2-weighted MRI using a 3-tier grading system. The grade of spiculation was correlated with the density of tumor buds quantified in histological sections of the respective surgical specimen according to the guidelines of the International Tumor Budding Consensus Conference (n = 28 patients). RESULTS: 64% of tumors revealed intermediate to high spiculation on MRI. In over 90% of cases, tumor buds were detected. We observed a significant positive rank correlation between the grade of radiological tumor spiculation and the histopathological number of tumor buds (rs = 0.745, p < 0.001). The number of tumor buds was not significantly associated with tumor stage, presence of lymph node metastases, or histopathological grading (p ≥ 0.352). CONCLUSION: Our study identifies a readily available radiological marker for non-invasive estimation of tumor budding, as a correlate for infiltrative tumor growth. This finding could help to identify PDAC patients who might benefit from more extensive peripancreatic soft tissue resection during surgery or stratify patients for personalized therapy concepts.

CD15 is a risk predictor and a novel target in clear cell renal cell carcinoma.

INTRODUCTION: Tumor cells use adhesion molecules like CD15 or sialylCD15 (sCD15) for metastatic spreading. We analyzed the expression of CD15 and sCD15 in clear cell renal cell carcinoma (ccRCC) regarding prognosis. METHODS: A tissue microarray containing tissue specimens of 763 patients with ccRCC was immunohistochemically stained for CD15 and sCD15, their expression quantified using digital image analysis and the impact on patients' survival analyzed. The cell lines 769p and 786o were stimulated with CD15 or control antibody in vitro and the effects on pathways activating AP-1 and tumor cell migration examined. RESULTS: ccRCC showed a broad range of CD15 and sCD15 expression. A high CD15 expression was significantly associated with favorable outcome (p<0.01) and low-grade tumor differentiation (p<0.001), whereas sCD15 had no significant prognostic value. Tumors with synchronous distant metastasis had a significantly lower CD15 expression compared to tumors without any (p<0.001) or with metachronous metastasis (p<0.01). Tumor cell migration was significantly reduced after CD15 stimulation in vitro, but there were no major effects on activating pathways of AP-1. CONCLUSION: CD15, but not sCD15, qualifies as a biomarker for risk stratification and as an interesting novel target in ccRCC. Moreover, the data indicates a contribution of CD15 to metachronous metastasis. Further research is warranted to decipher the intracellular pathways of CD15 signaling in ccRCC in order to characterize the CD15 effects on ccRCC more precisely.

Comprehensive clinicopathologic study of alpha fetoprotein-expression in a large cohort of patients with hepatocellular carcinoma.

Alpha fetoprotein (AFP) is the most widely used diagnostic and prognostic serum biomarker for hepatocellular carcinoma (HCC). Despite its wide clinical use, a systematic clinicopathologic study comparing AFP expression in HCC in situ with serum AFP concentrations has not yet been conducted. To analyze AFP expression in a large cohort of patients by immunohistochemistry, we employed a comprehensive tissue microarray with 871 different HCCs of overall 561 patients. AFP immunoreactivity was detected in only about 20% of HCC core biopsies, whereas 48.9% of the patients displayed increased serum values (>12 ng/mL). Immunostaining of whole tumor slides revealed that lack of detectable immunoreactivity in core biopsies in a subgroup of patients with elevated AFP serum concentrations is due to heterogeneous intratumoral AFP expression. Serum AFP concentrations and AFP expression in situ were moderately correlated (Spearman's rank correlation coefficient .53, P = 1.2e - 13). High AFP expression detected in serum (>227.3 ng/mL) or in situ predicted unfavorable prognosis and was associated with vascular invasion, higher tumor grade and macrotrabecular-massive tumor subtype. Multivariate and ROC curve analysis demonstrated that high AFP concentrations in serum is an independent prognostic parameter and represents the more robust prognostic predictor in comparison to AFP immunostaining of core biopsies. The previously published vessels encapsulating tumor clusters (VETC) pattern turned out as an additional, statistically independent prognostic parameter. AFP-positivity was associated with increased tumor cell apoptosis, but not with increased vascular densities. Additionally, AFP-positive tumors displayed increased proliferation rates, urea cycle dysregulation and signs of genomic instability, which may constitute the basis for their increased aggressiveness.

pT3 colorectal cancer revisited: a multicentric study on the histological depth of invasion in more than 1000 pT3 carcinomas-proposal for a new pT3a/pT3b subclassification.

BACKGROUND: Pathological TNM staging (pTNM) is the strongest prognosticator in colorectal carcinoma (CRC) and the foundation of its post-operative clinical management. Tumours that invade pericolic/perirectal adipose tissue generally fall into the pT3 category without further subdivision. METHODS: The histological depth of invasion into the pericolic/perirectal fat was digitally and conventionally measured in a training cohort of 950 CRCs (Munich). We biostatistically calculated the optimal cut-off to stratify pT3 CRCs into novel pT3a (≤3 mm)/pT3b (>3 mm) subgroups, which were then validated in two independent cohorts (447 CRCs, Bayreuth/542 CRCs, Mainz). RESULTS: Compared to pT3a tumours, pT3b CRCs showed significantly worse disease-specific survival, including in pN0 vs pN+ and colonic vs. rectal cancers (DSS: P < 0.001, respectively, pooled analysis of all cohorts). Furthermore, the pT3a/pT3b subclassification remained an independent predictor of survival in multivariate analyses (e.g. DSS: P < 0.001, hazard ratio: 4.41 for pT3b, pooled analysis of all cohorts). While pT2/pT3a CRCs showed similar survival characteristics, pT3b cancers remained a distinct subgroup with dismal survival. DISCUSSION: The delineation of pT3a/pT3b subcategories of CRC based on the histological depth of adipose tissue invasion adds valuable prognostic information to the current pT3 classification and implementation into current staging practices of CRC should be considered.

German S3 Evidence-Based Guidelines on Focal Therapy in Localized Prostate Cancer: The First Evidence-Based Guidelines on Focal Therapy.

BACKGROUND: Focal therapy (FT) is an option to treat localized prostate cancer (PCa) and preserve healthy prostate tissue in order to reduce known side effects from primary whole-gland treatment. The available FT modalities are manifold. Until now, national and international PCa guidelines have been cautious to propose recommendations regarding FT treatment since data from prospective controlled trials are lacking for most FT modalities. Moreover, none of the international guidelines provides a separate section on FT. In this purpose, we provide a synopsis of the consensus-based German S3 guidelines for a possible international use. SUMMARY: The recently published update of the German S3 guidelines, an evidence- and consensus-based guideline, provides a section on FT with recommendations for diagnostic work-up, indications, modalities, and follow-up. This section consists of 12 statements and recommendations for FT in the treatment of localized PCa. KEY MESSAGE: The German S3 guidelines on PCa are the first to incorporate recommendations for FT based on evidence and expert consensus including indication criteria for FT, pretreatment, and follow-up diagnostic pathways as well as an extended overview of FT techniques and the current supportive evidence.

Role of integrins in the metastatic spread of high-grade serous ovarian cancer.

PURPOSE: Integrins may be involved in the metastatic spread of high-grade serous ovarian cancer (HGSOC) which determines the therapeutical approach and prognosis. We investigated the integrin expression in primary tumor and metastases of advanced HGSOC. METHODS: The expression of integrin α2, α4, α5, α6, and ß1 was assessed by immunostaining in tumor samples of the ovary, omentum, and peritoneum of each patient. Differences in integrin expression among tumor localizations and their association with clinicopathological parameters were examined by Fisher's exact test. The impact of integrin expression on progression-free survival (PFS) and overall survival (OS) was examined by Cox regression and Kaplan-Meier analyses. RESULTS: Hundred and thirteen tumor samples of 40 HGSOC patients were examined. The expression of the integrins did not differ between the three tumor localizations (all p values > 0.05) with the exception of high expression of integrin α4 in primary tumor and omentum (52.5% versus 47.5%, p = 0.008) and primary tumor and peritoneum (52.5% versus 47.5%, p = 0.050). High expression of integrin α4 in peritoneum was associated with poorer PFS (HR 2.02 95% CI 1.01-4.05, p = 0.047), younger age (p = 0.047), and death (p = 0.046). Median PFS in patients with high expression of integrin α4 was 13.00 months, whereas median PFS in patients without high expression of integrin α4 was 21.00 months (p = 0.040). Expression of other integrins did not correlate with PFS or OS. CONCLUSION: Expression of integrin α4 may be altered during the metastatic spread of HGSOC and affect prognosis, whereas expression of integrin α2, α5, α6, and ß1 did not reveal any prognostic value.

Lipid Droplet-Associated Proteins Perilipin 1 and 2: Molecular Markers of Steatosis and Microvesicular Steatotic Foci in Chronic Hepatitis C.

Chronic infection with hepatitis C (HCV) is a major risk factor in the development of cirrhosis and hepatocellular carcinoma. Lipid metabolism plays a major role in the replication and deposition of HCV at lipid droplets (LDs). We have demonstrated the importance of LD-associated proteins of the perilipin family in steatotic liver diseases. Using a large collection of 231 human liver biopsies with HCV, perilipins 1 and 2 have been localized to LDs of hepatocytes that correlate with the degree of steatosis and specific HCV genotypes, but not significantly with the HCV viral load. Perilipin 1- and 2-positive microvesicular steatotic foci were observed in 36% of HCV liver biopsies, and also in chronic hepatitis B, autoimmune hepatitis and mildly steatotic or normal livers, but less or none were observed in normal livers of younger patients. Microvesicular steatotic foci did not frequently overlap with glycogenotic/clear cell foci as determined by PAS stain in serial sections. Steatotic foci were detected in all liver zones with slight architectural disarrays, as demonstrated by immunohistochemical glutamine synthetase staining of zone three, but without elevated Ki67-proliferation rates. In conclusion, microvesicular steatotic foci are frequently found in chronic viral hepatitis, but the clinical significance of these foci is so far not clear.

A multicentre analytical comparison study of inter-reader and inter-assay agreement of four programmed death-ligand 1 immunohistochemistry assays for scoring in triple-negative breast cancer.

AIMS: Studies in various cancer types have demonstrated discordance between results from different programmed death-ligand 1 (PD-L1) assays. Here, we compare the reproducibility and analytical concordance of four clinically developed assays for assessing PD-L1-positivity in tumour-infiltrating immune cells in the tumour area (PD-L1-IC-positivity) in triple-negative breast cancer (TNBC). METHODS AND RESULTS: Primary TNBC resection specimens (n = 30) were selected based on their PD-L1-IC-positivity per VENTANA SP142 (<1%: 15 cases; 1-5%: seven cases; >5%: eight cases). Serial histological sections were stained for PD-L1 using VENTANA SP142, VENTANA SP263, DAKO 22C3 and DAKO 28-8. PD-L1-IC-positivity and tumour cell expression (≥1 versus <1%) were scored by trained readers from seven sites using online virtual microscopy. The adjusted mean of PD-L1-IC-positivity for SP263 (7.8%) was significantly higher than those for the other three assays (3.7-4.9%). Differences in adjusted means were statistically significant between SP263 and the other three assays (P < 0.0001) but not between the three remaining assays when excluding SP263 (P = 0.0961-0.6522). Intra-class correlation coefficients revealed moderate-to-strong inter-reader agreement for each assay (0.460-0.805) and poor-to-strong inter-assay agreement for each reader (0.298-0.678) on PD-L1-IC-positivity. CONCLUSIONS: In this first multicentre study of different PD-L1 assays in TNBC, we show that PD-L1-IC-positivity for SP142, 22C3 and 28-8 was reproducible and analytically concordant, indicating that these three assays may be analytically interchangeable. The relevance of the higher PD-L1-IC-positivity for SP263 should be further investigated.

Response to neoadjuvant treatment among rectal cancer patients in a population-based cohort.

BACKGROUND: In rectal cancer, prediction of tumor response and pathological complete response (pCR) to neoadjuvant treatment could contribute to refine selection of patients who might benefit from a delayed- or no-surgery approach. The aim of this study was to explore the association of clinical and molecular characteristics of rectal cancer with response to neoadjuvant treatment and to compare patient survival according to level of response. METHODS: Resected rectal cancer patients were selected from a population-based cohort study. Molecular tumor markers were determined from the surgical specimen. Tumor response and pCR were defined as downstaging in T or N stage and absence of tumor cells upon pathological examination, respectively. The associations of patient and tumor characteristics with tumor response and pCR were explored, and patient survival was determined by degree of response to neoadjuvant treatment. RESULTS: Among 1536 patients with rectal cancer, 602 (39%) received neoadjuvant treatment. Fifty-five (9%) patients presented pCR, and 239 (49%) and 250 (53%) patients showed downstaging of the T and N stages, respectively. No statistically significant associations were observed between patient or tumor characteristics and tumor response or pCR. Patients who presented any type of response to neoadjuvant treatment had significantly better cancer-specific and overall survival compared with non-responders. CONCLUSION: In this study, patient characteristics were not associated with response to neoadjuvant treatment, and molecular characteristics determined after surgical resection of the tumor were not predictive of pCR or tumor downstaging. Future studies should include molecular biomarkers from biopsy samples before neoadjuvant treatment.

Vascular Inflammation and Dysfunction in Lupus-Prone Mice-IL-6 as Mediator of Disease Initiation.

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease and patients are under an increased risk for cardiovascular (CV) events and mortality. The increased CV risk for patients with SLE seems to be caused by a premature and accelerated atherosclerosis, attributable to lupus-specific risk factors (i.e., increased systemic inflammation, altered immune status), apart from traditional CV risk factors. To date, there is no established experimental model to explore the pathogenesis of this increased CV risk in SLE patients. METHODS: Here we investigated whether MRL-Faslpr mice, which develop an SLE-like phenotype, may serve as a model to study lupus-mediated vascular disease. Therefore, MRL-Faslpr, MRL-++, and previously generated Il6-/- MRL-Faslpr mice were used to evaluate vascular changes and possible mechanisms of vascular dysfunction and damage. RESULTS: Contrary to MRL-++ control mice, lupus-prone MRL-Faslpr mice exhibited a pronounced vascular and perivascular leukocytic infiltration in various organs; expression of pro-inflammatory cytokines in the aorta and kidney was augmented; and intima-media thickness of the aorta was increased. IL-6 deficiency reversed these changes and restored aortic relaxation. CONCLUSION: Our findings demonstrate that the MRL-Faslpr mouse model is an excellent tool to investigate vascular damage in SLE mice. Moreover, IL-6 promotes vascular inflammation and damage and could potentially be a therapeutic target for the treatment of accelerated arteriosclerosis in SLE.

[International publication activity during the COVID-19 pandemic]. / Internationale wissenschaftliche Publikationsaktivität zu COVID-19.

BACKGROUND: Pandemics lead to new challenges for healthcare systems and a subsequent shift of the scientific focus, which can partially be seen in alterations in scientific publication activity. OBJECTIVES: Follow-up on the global publication activity within the course of the COVID-19 pandemic in a comparison of national contexts with regards to local infection rates and the involvement of the discipline of pathology. MATERIALS AND METHODS: Comparative analysis of the number of publications in the PubMed® database concerning COVID-19 with respect to publication type, date and place of publication, affiliation to an institute of pathology, and correlation with the number of SARS-CoV­2 infections over the same timeframe. RESULTS: After an initial peak with regards to the number of publications in the months of May and June 2020, a slight decrease was observed, followed by another increase starting in August/September 2020. Further, the time between data collection and publication contracted to approximately 3-4 months. Countries faced with early SARS-CoV­2 infections published promptly, even though there was no overall association between the number of publications and COVID-19 case numbers. On average, 4% of authors were affiliated to an institute of pathology, with a steady increase of this percentage within the course of the pandemic. CONCLUSIONS: COVID-19 altered global publication activity by providing for an unprecedented number of publications combined with an acceleration of publication times irrespective of the geographical location and overall case numbers.

[Digital teaching in pathology: experiences from Mainz]. / Digitale Lehre in der Pathologie: Erfahrungen aus Mainz.

BACKGROUND: Due to the corona pandemic, digital teaching has become especially important in education and has led to a restructuring of teaching, not only in the subject of surgical pathology. OBJECTIVES: In this article, different forms of e­learning are presented and illustrated using the example of teaching surgical pathology and neuropathology at the University Medical Center Mainz. RESULTS: Before the onset of the corona pandemic in spring 2020, digitization had already assumed great importance for teaching in the technology- and method-oriented subject of surgical pathology. In particular, the possibility of virtual microscopy via scanned slides with a digital slide server has been used in many pathology institutes. Virtual microscopy often partially or completely replaced conventional microscopy of histologic slide collections. Complementary virtual learning offers are becoming more and more important. These include asynchronously provided lectures or macroscopy videos, video conferences, scripts and communication via learning platforms. In addition, electronic exams have become an indispensable part of teaching. Nevertheless, the corona pandemic revealed how important personal contact with students is to achieve optimal learning success; learning forms with a combination of face-to-face teaching and e­learning in the sense of blended learning are of particular importance. CONCLUSIONS: As part of blended learning, digital teaching is an ideal complement to face-to-face teaching and is changing teaching in the longer term, not only in the field of surgical pathology. Digital learning formats will remain in the future and will at least partially replace classroom formats such as lectures.

Postmenopausal hormone replacement therapy and colorectal cancer risk by molecular subtypes and pathways.

Postmenopausal hormone replacement therapy (HRT) was found to be associated with lower risk of colorectal cancer (CRC). However, little is known regarding associations with molecular subtypes of CRC. The current study includes female participants of a large German population-based case-control study (922 CRC cases and 1,183 controls). Tumor tissue samples were analyzed for microsatellite instability (MSI), CpG island methylator phenotype (CIMP), BRAF and KRAS mutation status. Multivariable logistic regression models were used to assess the association of HRT use with molecular subtypes and pathways. Postmenopausal HRT use was overall associated with reduced risk of CRC (adjusted odds ratio (aOR) 0.62, 95% confidence interval (CI) 0.50-0.76) and no major differences were observed for molecular subtypes or for tumor marker combinations representing molecular pathways. When stratified by median age (≤/>71 years) potentially stronger risk reductions were observed in the older group for subtypes showing MSI (OR = 0.36, 95% CI 0.17-0.76), BRAF mutation (OR = 0.40, 95% CI 0.30-0.83) and CIMP-high (OR = 0.40, 95% CI 0.21-0.73) and for CRC suggestive of the sessile serrated pathway (OR = 0.45, 95% CI 0.20-1.01). In conclusion, postmenopausal use of HRT was similarly associated with risk reduction of major molecular tumor subtypes and pathways of CRC. Potentially stronger risk reductions with CRC subtypes diagnosed at higher ages require confirmation and clarification from other studies. The current study extends the limited understanding of the mechanisms of HRT in CRC prevention.

Age-dependent performance of BRAF mutation testing in Lynch syndrome diagnostics.

BRAF V600E mutations have been reported as a marker of sporadic microsatellite instability (MSI) colorectal cancer (CRC). Current international diagnostic guidelines recommend BRAF mutation testing in MSI CRC patients to predict low risk of Lynch syndrome (LS). We evaluated the age-specific performance of BRAF testing in LS diagnostics. We systematically compared the prevalence of BRAF mutations in LS-associated CRCs and unselected MSI CRCs in different age groups as available from published studies, databases and population-based patient cohorts. Sensitivity/specificity analysis of BRAF testing for exclusion of LS and cost calculations were performed. Among 969 MSI CRCs from LS carriers in the literature and German HNPCC Consortium, 15 (1.6%) harbored BRAF mutations. Six of seven LS patients with BRAF-mutant CRC and reported age were <50 years. Among 339 of 756 (44.8%) of BRAF mutations detected in unselected MSI CRC, only 2 of 339 (0.6%) BRAF mutations were detected in patients <50 years. The inclusion of BRAF testing led to high risk of missing LS patients and increased costs at age <50 years. BRAF testing in patients <50 years carries a high risk of missing a hereditary cancer predisposition and is cost-inefficient. We suggest direct referral of MSI CRC patients <50 years to genetic counseling without BRAF testing.

Smoking, alcohol consumption and colorectal cancer risk by molecular pathological subtypes and pathways.

BACKGROUND: Smoking and alcohol increase risk for colorectal malignancies. However, colorectal cancer (CRC) is a heterogenic disease and associations with the molecular pathological pathways are unclear. METHODS: This population-based case-control study includes 2444 cases with first-diagnosis CRC and 2475 controls. Tumour tissue was analysed for MSI (microsatellite instability), CIMP (CpG island methylator phenotype), BRAF (B-Raf proto-oncogene serine/threonine kinase gene) and KRAS (Kirsten rat sarcoma viral oncogene homologue gene) mutations. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated for associations between alcohol and smoking and CRC molecular subtypes and pathways. RESULTS: Current smoking showed higher ORs for MSI-high (OR = 2.79, 95% CI: 1.86-4.18) compared to MSS (OR = 1.41, 1.14-1.75, p-heterogeneity (p-het) = 0.001), BRAF-mutated (mut) (OR = 2.40, 1.41-4.07) compared to BRAF-wild type (wt) (OR = 1.52, 1.24-1.88, p-het = 0.074), KRAS-wt (OR = 1.70, 1.36-2.13) compared to KRAS-mut (OR = 1.26, 0.95-1.68, p-het = 0.039) and CIMP-high (OR = 2.01, 1.40-2.88) compared to CIMP-low/negative CRC (OR = 1.50, 1.22-1.85, p-het=0.101). Current smoking seemed more strongly associated with sessile serrated pathway (CIMP-high + BRAF-mut; OR = 2.39, 1.27-4.52) than with traditional pathway CRC (MSS + CIMP-low/negative + BRAF-wt; OR = 1.50, 1.16-1.94) and no association was observed with alternate pathway CRC (MSS + CIMP-low/negative + KRAS-wt; OR = 1.08, 0.77-1.43). No heterogeneity was observed in alcohol consumption association by molecular subtypes. CONCLUSIONS: In this large case-control study, smoking was more strongly associated with MSI-high and KRAS-wt CRC and with cases showing features of the sessile serrated pathway. Association patterns were less clear for alcohol consumption.

Colonoscopy and Reduction of Colorectal Cancer Risk by Molecular Tumor Subtypes: A Population-Based Case-Control Study.

INTRODUCTION: In previous studies, the protective effect of colonoscopy was generally stronger for distal colorectal cancer than for proximal colorectal cancer (CRC). This study aimed to investigate whether reduction of CRC risk through colonoscopy varies according to major tumor markers and pathways of CRC. METHODS: This is a population-based case-control study from Germany, including 2,132 patients with a first diagnosis of CRC and information on major molecular tumor markers and 2,486 control participants without CRC. Detailed participant characteristics were collected by standardized questionnaires. Information on previous colonoscopy was derived from medical records. Polytomous logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between previous colonoscopy and subtypes of CRC. RESULTS: Overall, we observed strong risk reduction of CRC after colonoscopy that was weaker for microsatellite instable (MSI) than for non-MSI CRC (OR 0.70, 95% CI 0.50-0.97 vs OR 0.28, 95% CI 0.24-0.33), for CpG island methylator phenotype high CRC than for CpG island methylator phenotype low/negative CRC (OR 0.45, 95% CI 0.34-0.59 vs OR 0.29, 95% CI 0.25-0.34), for BRAF-mutated than for BRAF nonmutated CRC (OR 0.62, 95% CI 0.42-0.91 vs OR 0.30, 95% CI 0.25-0.35), for KRAS nonmutated than for KRAS-mutated CRC (OR 0.34, 95% CI 0.29-0.40 vs OR 0.26, 95% CI 0.20-0.32), and for CRC classified into the sessile serrated pathway than for CRC of the traditional pathway (OR 0.57, 95% CI 0.36-0.91 vs OR 0.30, 95% CI 0.25-0.37). After colonoscopy with the detection of adenomas or hyperplastic polyps, no risk reduction was found for sessile serrated pathway CRC, MSI, and BRAF-mutated subtypes. DISCUSSION: Our study extends the molecular understanding of existing differences in risk reduction of proximal and distal CRCs reported by previous studies and may imply important information for improving strategies for timely detection of relevant precursors.

Perilipin 1 Expression Differentiates Liposarcoma from Other Types of Soft Tissue Sarcoma.

Lipid droplets, a morphologic feature of adipocytic tumors, are strongly regulated by associated proteins of the perilipin/PAT (perilipin, adipophilin, and tail-interacting protein of 47 kD) family. So far, the use of perilipins as markers for differential diagnosis of soft tissue tumors has only been studied in a few cases. The aim of this study was to investigate the expression of perilipins in 478 human soft tissue tumors and 60 respective normal tissues. Perilipin 1 was immunohistochemically positive in all studied cases of well-differentiated liposarcomas, >90% of myxoid round cell liposarcomas, and >70% of pleomorphic liposarcomas, whereas only the differentiated components of dedifferentiated liposarcomas were immunohistochemically positive for perilipin 1. All other types of soft tissue sarcomas were negative for perilipin 1. Perilipin 2 was more prominent in dedifferentiated and pleomorphic liposarcomas and nearly all other high-grade sarcomas. In well-differentiated liposarcomas, lipomas, or normal adipose tissue, perilipin 2 was virtually absent. In addition, long-term stimulation of adipogenesis in the liposarcoma cell line LiSa-2 restored perilipin 1 expression, as exhibited in the source tumor. Furthermore, knockdown of perilipin 2 or perilipin 3 in LiSa-2 cells influenced lipid droplet number and size as well as cell vitality. In summary, perilipin 1 is a promising marker for the differential diagnosis of liposarcomas from other soft tissue sarcomas, whereas perilipin 2 correlates negatively with tumor grade and may be therapeutically useful.

Young-onset gastric cancer and Epstein-Barr Virus (EBV) - a major player in the pathogenesis?

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer death, occurs predominantly in older age, with increasing incidence in young patients. The Cancer Genome Atlas indicates four subtypes for GC among which Epstein-Barr virus (EBV) subtype is estimated at 8.7%. We aim to determine the prevalence of EBV subtype in young GC patients (≤45 years) compared with an average-onset cohort (≥55 years) and characterize the clinicopathologic pattern of young-onset GC. METHODS: Gastric cancer samples of patients of both cohorts were screened for EBV by qPCR. Additional staining was done for Human epidermal growth factor receptor 2 (HER2), microsatellite instability (MSI) status and Programmed death-ligand 1 (PD-L1). Demographics and clinical data were retrieved from the medical records. RESULTS: Thirty-nine young-onset and 35 average-onset GC patients were reviewed. There was no apparent difference in tumor location, family history, histology and HER2 status between the cohorts. More young-onset patients were diagnosed with metastatic disease (27% vs 9%, p = 0.0498). EBV was significantly more prevalent in the young-onset cohort (33% vs 11%, p = 0.025). 15/17 EBV positive patients were under the median age of diagnosis for GC in the US (68 years). MSI-H was found only in the average-onset cohort [0% vs 27%, p = 0.001). PD-L1 positivity was higher in the young-onset cohort (31% vs 3%, p = 0.002). CONCLUSION: Our study indicates that EBV subtype is more prevalent in young-onset GC and may play a key role in the pathogenesis. Higher rate of PD-L1 positivity in young-onset GC could change treatment strategies. We are currently evaluating these findings in a prospective trial.