Development of a prognostic risk model for clear cell renal cell carcinoma by systematic evaluation of DNA methylation markers.

BACKGROUND: Current risk models for renal cell carcinoma (RCC) based on clinicopathological factors are sub-optimal in accurately identifying high-risk patients. Here, we perform a head-to-head comparison of previously published DNA methylation markers and propose a potential prognostic model for clear cell RCC (ccRCC). PATIENTS AND METHODS: Promoter methylation of PCDH8, BNC1, SCUBE3, GREM1, LAD1, NEFH, RASSF1A, GATA5, SFRP1, CDO1, and NEURL was determined by nested methylation-specific PCR. To identify clinically relevant methylated regions, The Cancer Genome Atlas (TCGA) was used to guide primer design. Formalin-fixed paraffin-embedded (FFPE) tissue samples from 336 non-metastatic ccRCC patients from the prospective Netherlands Cohort Study (NLCS) were used to develop a Cox proportional hazards model using stepwise backward elimination and bootstrapping to correct for optimism. For validation purposes, FFPE ccRCC tissue of 64 patients from the University Hospitals Leuven and a series of 232 cases from The Cancer Genome Atlas (TCGA) were used. RESULTS: Methylation of GREM1, GATA5, LAD1, NEFH, NEURL, and SFRP1 was associated with poor ccRCC-specific survival, independent of age, sex, tumor size, TNM stage or tumor grade. Moreover, the association between GREM1, NEFH, and NEURL methylation and outcome was shown to be dependent on the genomic region. A prognostic biomarker model containing GREM1, GATA5, LAD1, NEFH and NEURL methylation in combination with clinicopathological characteristics, performed better compared to the model with clinicopathological characteristics only (clinical model), in both the NLCS and the validation population with a c-statistic of 0.71 versus 0.65 and a c-statistic of 0.95 versus 0.86 consecutively. However, the biomarker model had limited added prognostic value in the TCGA series with a c-statistic of 0.76 versus 0.75 for the clinical model. CONCLUSION: In this study we performed a head-to-head comparison of potential prognostic methylation markers for ccRCC using a novel approach to guide primers design which utilizes the optimal location for measuring DNA methylation. Using this approach, we identified five methylation markers that potentially show prognostic value in addition to currently known clinicopathological factors.

Long-term dietary sodium, potassium and fluid intake; exploring potential novel risk factors for renal cell cancer in the Netherlands Cohort Study on diet and cancer.

BACKGROUND: As sodium, potassium and fluid intake are related to hypertension, an established risk factor for renal cell cancer (RCC), they may be independent risk factors for RCC. METHODS: The Netherlands Cohort Study (NLCS) with case-cohort design included 120,852 participants aged 55-69 years. At baseline, diet and lifestyle were assessed with questionnaires. After 17.3 years of follow-up, 485 RCC cases and 4438 subcohort members were available for analyses. RESULTS: Sodium intake increased RCC risk (P-trend=0.03), whereas fluid and potassium intake did not. For high sodium and low fluid intake, the RCC risk additionally increased (P-interaction=0.02). CONCLUSION: Sodium intake is a potential risk factor for RCC, particularly if fluid consumption is low.

High-grade clear cell renal cell carcinoma has a higher angiogenic activity than low-grade renal cell carcinoma based on histomorphological quantification and qRT-PCR mRNA expression profile.

Clear cell renal cell carcinoma (CC-RCC) is a highly vascularised tumour and is therefore an attractive disease to study angiogenesis and to test novel angiogenesis inhibitors in early clinical development. Endothelial cell proliferation plays a pivotal role in the process of angiogenesis. The aim of this study was to compare angiogenesis parameters in low nuclear grade (n=87) vs high nuclear grade CC-RCC (n=63). A panel of antibodies was used for immunohistochemistry: CD34/Ki-67, carbonic anhydrase IX, hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF). Vessel density (MVD - microvessel density), endothelial cell proliferation fraction (ECP%) and tumour cell proliferation fraction (TCP%) were assessed. mRNA expression levels of angiogenesis stimulators and inhibitors were determined by quantitative RT-PCR. High-grade CC-RCC showed a higher ECP% (P=0.049), a higher TCP% (P=0.009), a higher VEGF protein expression (P<0.001), a lower MVD (P< 0.001) and a lower HIF-1alpha protein expression (P=0.002) than low-grade CC-RCC. Growth factor mRNA expression analyses revealed a higher expression of angiopoietin 2 in low-grade CC-RCC. Microvessel density and ECP% were inversely correlated (Rho=-0.26, P=0.001). Because of the imperfect association of nuclear grade and ECP% or MVD, CC-RCC was also grouped based on low/high MVD and ECP%. This analysis revealed a higher expression of vessel maturation and stabilisation factors (placental growth factor, PDGFB1, angiopoietin 1) in CC-RCC with high MVD, a group of CC-RCC highly enriched in low nuclear grade CC-RCC, with low ECP%. Our results suggest heterogeneity in angiogenic activity and vessel maturation of CC-RCC, to a large extent linked to nuclear grade, and, with probable therapeutic implications.

Major brain lesions by intrauterine herpes simplex virus infection: MRI contribution.

The majority of neonatal Herpes Simplex Virus (HSV) infections are acquired at birth as a consequence of direct fetal contact with the infected birth canal or through an ascending infection after premature rupture of the amniotic membranes. Intrauterine transmission of HSV infection from mother to the fetus is rare; in only 5% of the cases it occurs from haematogenous transplacental dissemination. We present a case of transplacental intrauterine HSV infection after a primary maternal HSV infection in the first trimester of pregnancy. The diagnosis was assessed by viral culture and serologic tests. Ultrasound imaging revealed fetal brain damage in the third trimester. Finally, the MRI showed the devastating extensiveness of the HSV infection, which was beyond the expectation based on the ultrasound images.

[From gene to disease; PKHD1 and recessive polycystic kidney disease]. / Van gen naar ziekte; PKHD1 en recessief erfelijke cystennieren.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe form of polycystic kidney disease characterised by enlarged kidneys and congenital hepatic fibrosis. The disease has an incidence of 1:7000-:20,000 and is caused by mutations in the PKHD1 gene, which under normal conditions produces the protein fibrocystin, also named polyductin. This protein may be a transmembrane receptor or ligand that plays a role in collecting duct and biliary differentiation. The major site of expression is the primary cilium, and in particular the basal body of the cilium, underlining a link between aberrant cilial function and cystogenesis. Prenatal diagnostics is possible using DNA analysis or ultrasonography.

Intermittent subobstruction and cholestasis as complications of duodenal amyloid tumours.

Amyloidosis confined to the duodenum is uncommon. In the present report the history of an 83-year old patient, admitted for vomiting and heavy epigastric pain, is described. Radiographic and endoscopic investigation revealed two polypoid lesions in the duodenum (D2). Biopsies showed diffuse amyloid deposition in the lamina propria, muscularis mucosae and submucosa of the duodenum as well as vascular deposits. No other localisations were documented. Amyloid tumours of the gastrointestinal tract are rare but may lead to serious symptoms.

Florid basal cell hyperplasia of the prostate.

Florid basal cell hyperplasia of the prostate is an uncommon proliferative condition, most often associated with adenomatous hyperplasia. It is considered a benign lesion although confusion with prostatic cancer is possible when one is not familiar with the histopathological appearance. We report another two cases of the glandular type of basal cell hyperplasia with immunohistochemical findings. Both lesions were composed of crowded and rather small glands with piling up of basaloid cells. They showed immunohistochemical positivity for high molecular weight cytokeratin 34 beta E12, confirming their relationship with basal cells. We detected focal positivity of these basal cells for alpha-smooth muscle actin, suggesting myoepithelial differentiation. Paucity of actin-positive smooth muscle cells in the stroma was noticed. One of the lesions showed some mild cytological atypia with prominent nucleoli and increased mitotic activity.