Asynchronous locking in metamaterials of fluids of light and sound

Lattices of exciton-polariton condensates represent an attractive platform for the study and implementation of non-Hermitian bosonic quantum systems with strong non-linear interactions. The possibility to actuate on them with a time dependent drive could provide for example the means to induce resonant inter-level transitions, or to perform Floquet engineering or Landau-Zener-Stückelberg state preparation. Here, we introduce polaromechanical metamaterials, two-dimensional arrays of μm-sized traps confining zero-dimensional light-matter polariton fluids and GHz phonons. A strong exciton-mediated polariton-phonon interaction induces a time-dependent inter-site polariton coupling J(t) with remarkable consequences for the dynamics. When locally perturbed by continuous wave optical excitation, a mechanical self-oscillation sets-in and polaritons respond by locking the energy detuning between neighbor sites at integer multiples of the phonon energy, evidencing asynchronous locking involving the polariton and phonon fields. These results open the path for the coherent control of dissipative quantum light fluids with hypersound in a scalable platform.

Analysis of metastases rates during follow-up after endoscopic resection of early "high-risk" esophageal adenocarcinoma

BACKGROUND AND AIMS

After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histologic features for lymph node metastases (ie, submucosal invasion, poor differentiation grade, or lymphovascular invasion) remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC.

METHODS

For this retrospective cohort study, data were collected from all Dutch patients managed with endoscopic follow-up (endoscopy, EUS) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. The primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology.

RESULTS

One hundred twenty patients met the selection criteria. Median follow-up was 29 months (interquartile range, 15-48). Metastases were observed in 5 of 25 (annual risk, 6.9%; 95% confidence interval [CI], 3.0-15) high-risk intramucosal cancers, 1 of 55 (annual risk, .7%; 95% CI, 0-4.0) low-risk submucosal cancers, and 3 of 40 (annual risk, 3.0%; 95% CI, 0-7.0) high-risk submucosal cancers.

CONCLUSIONS

Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available.

Significant variation in histopathological assessment of endoscopic resections for Barrett's neoplasia suggests need for consensus reporting: propositions for improvement

Endoscopic resection (ER) is an important diagnostic step in management of patients with early Barrett's esophagus (BE) neoplasia. Based on ER specimens, an accurate histological diagnosis can be made, which guides further treatment. Based on depth of tumor invasion, differentiation grade, lymphovascular invasion, and margin status, the risk of lymph node metastases and local recurrence is judged to be low enough to justify endoscopic management, or high enough to warrant invasive surgical esophagectomy. Adequate assessment of these histological risk factors is therefore of the utmost importance. Aim of this study was to assess pathologist concordance on these histological features on ER specimens and evaluate causes of discrepancy. Of 62 challenging ER cases, one representative H&E slide and matching desmin and endothelial marker were digitalized and independently assessed by 13 dedicated GI pathologists from 8 Dutch BE expert centers, using an online assessment module. For each histological feature, concordance and discordance were calculated. Clinically relevant discordances were observed for all criteria. Grouping depth of invasion categories according to expanded endoscopic treatment criteria (T1a and T1sm1 vs. T1sm2/3), ≥1 pathologist was discrepant in 21% of cases, increasing to 45% when grouping diagnoses according to the traditional T1a versus T1b classification. For differentiation grade, lymphovascular invasion, and margin status, discordances were substantial with 27%, 42%, and 32% of cases having ≥1 discrepant pathologist, respectively. In conclusion, histological assessment of ER specimens of early BE cancer by dedicated GI pathologists shows significant discordances for all relevant histological features. We present propositions to improve definitions of diagnostic criteria.

Compact acousto-optic multimode interference device in (Al,Ga)As

Multimode interference (MMI) devices are key components in modern integrated photonic circuits. Here, we present acoustically tuned optical switches on an (Al,Ga)As platform that enable robust, compact and fast response systems improving on recently demonstrated technology. The device consists of a 2 × 2 MMI device fine-tuned in its center region by a focused surface acoustic wave (SAW) beam working in the low GHz range. In this way, we can tune the refractive index profile over a narrow modulation region and thus control the optical switching behaviour via the applied SAW intensity. Direct tuning of the MMI device avoids losses and phase errors inherent to arrayed waveguide based switches, while also reducing the dimensions of the photonic circuit.

Residual disease after neoadjuvant chemoradiotherapy for oesophageal cancer: locations undetected by endoscopic biopsies in the preSANO trial

Background

Active surveillance has been proposed for patients with oesophageal cancer in whom there is a complete clinical response after neoadjuvant chemoradiotherapy (nCRT). However, endoscopic biopsies have limited negative predictive value in detecting residual disease. This study determined the location of residual tumour following surgery to improve surveillance and endoscopic strategies.

Methods

The present study was based on patients who participated in the prospective preSANO trial with adenocarcinoma or squamous cell carcinoma of the oesophagus or oesophagogastric junction treated in four Dutch hospitals between 2013 and 2016. Resection specimens and endoscopic biopsies taken during clinical response evaluations after nCRT were reviewed by two expert gastrointestinal pathologists. The exact location of residual disease in the oesophageal wall was determined in resection specimens. Endoscopic biopsies were assessed for the presence of structures representing the submucosal layer of the oesophageal wall.

Results

In total, 119 eligible patients underwent clinical response evaluations after nCRT followed by standard surgery. Residual tumour was present in endoscopic biopsies from 70 patients, confirmed on histological analysis of the resected organ. Residual tumour was present in the resection specimen from 27 of the other 49 patients, despite endoscopic biopsies being negative. Of these 27 patients, residual tumour was located in the mucosa in 18, and in the submucosa beneath tumour‐free mucosa in eight. One patient had tumour in muscle beneath tumour‐free mucosa and submucosa.

Conclusion

Most residual disease after nCRT missed by endoscopic biopsies was located in the mucosa. Active surveillance could be improved by more sampling and considering submucosal biopsies.

Frequency and power stabilization of a terahertz quantum-cascade laser using near-infrared optical excitation

We demonstrate a technique to simultaneously stabilize the frequency and output power of a terahertz quantum-cascade laser (QCL). This technique exploits frequency and power variations upon near-infrared illumination of the QCL with a diode laser. It does not require an external terahertz optical modulator. By locking the frequency to a molecular absorption line, we obtain a long-term (one-hour) linewidth of 260 kHz (full width at half maximum) and a root-mean-square power stability below 0.03%. With respect to the free-running case, this stabilization scheme improves the frequency stability by nearly two orders of magnitude and the power stability by a factor of three.

Tumor microRNA-126 controls cell viability and associates with poor survival in patients with esophageal adenocarcinoma

Esophageal adenocarcinoma displays a poor prognosis and current treatments are often not curative. Pathological TNM-stage is a prognostic parameter, but a better understanding of the pathophysiology of esophageal adenocarcinoma is needed to better predict survival. Recent work in other malignancies indicated an important role for the regulator microRNA-126 (miR-126) in tumors. The aim of this study was to investigate the function of miR-126 in esophageal adenocarcinoma and to correlate expression of miR-126 with tumor cell behavior and patient survival. Functional assays were performed in esophageal adenocarcinoma cell lines (OE33) in vitro by overexpressing or antagonizing miR-126 and assessing cellular processes linked to the hallmarks of cancer. In vivo pre-treatment biopsies of 58 patients with esophageal adenocarcinoma who underwent neoadjuvant chemoradiotherapy and surgery were analyzed for miR-126 expression in tumor cells by qRT-PCR and patient survival was analyzed by Kaplan–Meier and Cox regression. In OE33 cancer cells, stable overexpression of miR-126 modest though significantly altered expression of genes related to cell death (MEK1) and DNA repair (POLB and TERF1) was observed. Also the secretion of the angiogenic and pro-inflammatory factors, VEGF, IL-1β, and IL-6 were regulated by miR-126 ( P < 0.029). Importantly, miR-126 was found to be a regulator of cell viability in OE33 cells. Overexpressing ( P = 0.043) and antagonizing ( P = 0.035) miR-126 showed reciprocal effects on tumor cell viability and significantly regulated expression of pro- and anti-apoptotic genes, TP53, and GATA6 ( P < 0.031). In patients, high levels of miR-126 expression in pre-treatment tumors were significantly associated with poor survival ( P = 0.031). In multivariable analysis, high miR-126 ( P = 0.038) together with ypN-stage ( P = 0.048) were shown to be independent risk factors for poor survival. In conclusion, high expression of miR-126 in esophageal adenocarcinoma prevents tumor-cell death and is associated with poor patient survival. This study warrants further analysis of miR-126 as biomarker or potential therapeutic target for OAC.

Impact statement

Esophageal adenocarcinoma is a common form of cancer of the esophagus. It has an increasing health impact as it is associated with very poor patient survival. A better understanding of the pathophysiology of this cancer is needed to identify better treatment strategies and to provide a better prognosis for these patients. MicroRNAs have emerged as important molecular regulators of cancer cell viability and proliferation. The aim of our study was to investigate the role of one very well established microRNA, miR-126, in esophageal adenocarcinoma. Our research shows clear experimental evidence that miR-126 controls cell viability of esophageal adenocarcinoma cells. High (over)expression of miR-126 increased the viability of these cells. Our preclinical data were shown to be clinically relevant for this field of oncology. In an independent validation study of esophageal adenocarcinoma biopsies, we confirmed that high miR-126 expression in tumor cells was an independent risk factor for poor patient survival.

Adherence to pre-set benchmark quality criteria to qualify as expert assessor of dysplasia in Barrett's esophagus biopsies - towards digital review of Barrett's esophagus

Background

Dysplasia assessment of Barrett’s esophagus biopsies is associated with low observer agreement; guidelines advise expert review. We have developed a web-based review panel for dysplastic Barrett’s esophagus biopsies.

Objective

The purpose of this study was to test if 10 gastrointestinal pathologists working at Dutch Barrett’s esophagus expert centres met pre-set benchmark scores for quality criteria.

Methods

Ten gastrointestinal pathologists twice assessed 60 digitalized Barrett’s esophagus cases, enriched for dysplasia; then randomised (7520 assessments). We tested predefined benchmark quality criteria: (a) percentage of ‘indefinite for dysplasia’ diagnoses, benchmark score ≤14% for all cases, ≤16% for dysplastic subset, (b) intra-observer agreement; benchmark score ≥0.66/≥0.39, (c) percentage agreement with ‘gold standard diagnosis’; benchmark score ≥82%/≥73%, (d) proportion of cases with high-grade dysplasia underdiagnosed as non-dysplastic Barrett’s esophagus; benchmark score ≤1/78 (≤1.28%) assessments for dysplastic subset.

Results

Gastrointestinal pathologists had seven years’ Barrett’s esophagus-experience, handling seven Barrett’s esophagus-cases weekly. Three met stringent benchmark scores; all cases and dysplastic subset, three met extended benchmark scores. Four pathologists lacked one quality criterion to meet benchmark scores.

Conclusion

Predefined benchmark scores for expert assessment of Barrett’s esophagus dysplasia biopsies are stringent and met by some gastrointestinal pathologists. The majority of assessors however, only showed limited deviation from benchmark scores. We expect further training with group discussions will lead to adherence of all participating gastrointestinal pathologists to quality criteria, and therefore eligible to join the review panel.

Wideband, high-resolution terahertz spectroscopy by light-induced frequency tuning of quantum-cascade lasers

Near-infrared optical excitation enables wideband frequency tuning of terahertz quantum-cascade lasers. In this work, we demonstrate the feasibility of the approach for molecular laser absorption spectroscopy. We present a physical model which explains the observed frequency tuning characteristics by the optical excitation of an electron-hole plasma. Due to an improved excitation configuration as compared to previous work, we observe a single-mode continuous-wave frequency coverage of as much as 40 GHz for a laser at 3.1 THz. This represents, for the same device, a ten-fold improvement over the usually employed tuning by current. The method can be readily applied to a large class of devices.

Hotspot DAXX, PTCH2 and CYFIP2 mutations in pancreatic neuroendocrine neoplasms

Mutations in DAXX/ATRX, MEN1 and genes involved in the phosphoinositide-3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway have been implicated in pancreatic neuroendocrine neoplasms (pNENs). However, mainly mutations present in the majority of tumor cells have been identified, while proliferation-driving mutations could be present only in small fractions of the tumor. This study aims to identify high- and low-abundance mutations in pNENs using ultra-deep targeted resequencing. Formalin-fixed paraffin-embedded matched tumor-normal tissue of 38 well-differentiated pNENs was sequenced using a HaloPlex targeted resequencing panel. Novel amplicon-based algorithms were used to identify both single nucleotide variants (SNVs) and insertion-deletions (indels) present in >10% of reads (high abundance) and in <10% of reads (low abundance). Found variants were validated by Sanger sequencing. Sequencing resulted in 416,711,794 reads with an average target base coverage of 2663 ± 1476. Across all samples, 32 high-abundance somatic, 3 germline and 30 low-abundance mutations were withheld after filtering and validation. Overall, 92% of high-abundance and 84% of low-abundance mutations were predicted to be protein damaging. Frequently, mutated genes were MEN1, DAXX, ATRX, TSC2, PI3K/Akt/mTOR and MAPK-ERK pathway-related genes. Additionally, recurrent alterations on the same genomic position, so-called hotspot mutations, were found in DAXX, PTCH2 and CYFIP2. This first ultra-deep sequencing study highlighted genetic intra-tumor heterogeneity in pNEN, by the presence of low-abundance mutations. The importance of the ATRX/DAXX pathway was confirmed by the first-ever pNEN-specific protein-damaging hotspot mutation in DAXX. In this study, both novel genes, including the pro-apoptotic CYFIP2 gene and hedgehog signaling PTCH2, and novel pathways, such as the MAPK-ERK pathway, were implicated in pNEN.

Kaniner und feliner Diabetes mellitus – ein epidemiologischer Rückblick (1996–2006)

Gegenstand und Ziel: Bestimmung der Prävalenz und Risikofaktoranalyse des Diabetes mellitus bei Hund und Katze am Patientenkollektiv der Tierärztlichen Hochschule Hannover. Material und Methoden: Retrospektiv wurden alle diabetischen Patienten der Klinik für Kleintiere der Tierärztlichen Hochschule Hannover in den Jahren 1996 bis 2006 nach Gewicht, Alter, Rasse und Geschlecht analysiert. Ergebnisse: In diesem 11-jährigen Untersuchungszeitraum litten 10 von 1000 Katzen und 4 von 1000 vorgestellten Hunden an Diabetes mellitus. Der feline Diabetes mellitus weist im Vergleich zum kaninen Diabetes mellitus eine steigende Tendenz auf. Im Geschlechtervergleich der Katzen repräsentieren kastrierte Kater mit 1,52% die größte Gruppe. Mit 0,79% sind kastrierte Hündinnen am häufigsten betroffen. Das Verhältnis von diabetischen Hündinnen zu Rüden liegt bei 2 : 1. Im Rassenvergleich ergibt sich bei Cairn Terrier und West Highland White Terrier eine erhöhte Inzidenz des Diabetes mellitus, während Schäferhunde und Dackel eine signifikant nierigere Prävalenz aufweisen. Schlussfolgerung: Die Prävalenz des Diabetes mellitus nimmt bei der Katze im Gegensatz zum Hund im norddeutschen Patientenkollektiv zu. An diesem Patientengut wurden folgende Risikofaktoren ermittelt: zunehmendes Alter, männliches Geschlecht und Gewicht für Katzen; mittleres Alter, weibliches Geschlecht und Kastration für Hunde. Klinische Relevanz: Die Entstehung des kaninen und felinen Diabetes mellitus ist multifaktoriell und daher nach wie vor eine große Herausforderung für Kliniker und Forscher. Aus diesem Grund kommt der Identifizierung von Risikofaktoren für das bessere Verständnis sowie die Erarbeitung neuer Präventionsmaßnahmen und Behandlungskonzepte herausragende Bedeutung zu.

Active surveillance in clinically complete responders after neoadjuvant chemoradiotherapy for esophageal or junctional cancer

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is standard of care for locally advanced esophageal cancer in many countries. After nCRT up to one third of all patients have a pathologically complete response in the resection specimen, posing an ethical imperative to reconsider the necessity of standard surgery in all operable patients after nCRT. An active surveillance strategy following nCRT, in which patients are subjected to frequent clinical investigations after the completion of neoadjuvant therapy, has been evaluated in other types of cancer with promising results. In esophageal cancer, both patients who are cured by neoadjuvant therapy alone as well as patients with subclinical disseminated disease at the time of completion of neoadjuvant therapy may benefit from such an organ sparing approach. Active surveillance is currently applied in selected patients with esophageal cancer who refuse surgery or are medically unfit for major surgery after completion of nCRT, but this strategy is not (yet) adopted as an alternative to standard surgery or definitive chemoradiation. The available literature is scarce, but suggests that long-term oncological outcomes after active surveillance are noninferior compared to standard surgical resection, providing justification for comparison of both treatments in a phase III trial. This review gives an overview of the current knowledge regarding active surveillance after completion of nCRT in esophageal cancer and outlines future research perspectives.

Loss of SRY-box2 (SOX2) expression and its impact on survival of patients with oesophageal adenocarcinoma

BACKGROUND

Oesophageal adenocarcinoma (OAC) is a highly aggressive malignancy with poor survival, which is highly variable amongst patients with comparable conventional prognosticators. Therefore molecular biomarkers are urgently needed to improve the prediction of survival in these patients. SRY (sex determining region Y)-box 2, also known as SOX2, is a transcription factor involved in embryonal development of the gastrointestinal tract as well as in carcinogenesis. The purpose of this study was to see whether SOX2 expression is associated with survival in patients with OAC.

METHODS

SOX2 was studied by immunohistochemistry in patients who had undergone potentially curative oesophagectomy for adenocarcinoma. Protein expression of SOX2 was evaluated using tissue microarrays from resection specimens, and results were analysed in relation to the clinical data by Cox regression analysis. SOX2 was evaluated in two independent OAC cohorts (Rotterdam cohort and a multicentre UK cohort).

RESULTS

Loss of SOX2 expression was independently predictive of adverse overall survival in the multivariable analysis, adjusted for known factors influencing survival, in both cohorts (Rotterdam cohort: hazard ratio (HR) 1·42, 95 per cent c.i. 1·07 to 1·89, P = 0·016; UK cohort: HR 1·54, 1·08 to 2·19, P = 0·017). When combined with clinicopathological staging, loss of SOX2 showed an increased effect in patients with pT1-2 tumours (P = 0·010) and node-negative OAC (P = 0·038), with an incrementally adverse effect on overall survival for stage I OAC with SOX2 loss (HR 3·18, 1·18 to 8·56; P = 0·022).

CONCLUSION

SOX2 is an independent prognostic factor for long-term survival in OAC, especially in patients with stage I OAC.

Gonadal dysgenesis in disorders of sex development: Diagnosis and surgical management

Recent studies on gonadal histology have improved the understanding of germ cell malignancy risk in patients with disorders of sex development (DSD), and evidence-based gonadal management strategies are gradually emerging. Especially in 46,XY DSD and 45,X/46,XY DSD, which are characterized by gonadal dysgenesis, the risk of germ cell malignancy is significantly increased. This paper summarized the progress over the past 10 years in malignancy risk assessment in patients with DSD, and its implications for optimal surgical handling of the involved gonads.

A multicentre comparative prospective blinded analysis of EUS and MRI for screening of pancreatic cancer in high-risk individuals

OBJECTIVE

Endoscopic ultrasonography (EUS) and MRI are promising tests to detect precursors and early-stage pancreatic ductal adenocarcinoma (PDAC) in high-risk individuals (HRIs). It is unclear which screening technique is to be preferred. We aimed to compare the efficacy of EUS and MRI in their ability to detect clinically relevant lesions in HRI.

DESIGN

Multicentre prospective study. The results of 139 asymptomatic HRI (>10-fold increased risk) undergoing first-time screening by EUS and MRI are described. Clinically relevant lesions were defined as solid lesions, main duct intraductal papillary mucinous neoplasms and cysts ≥10 mm. Results were compared in a blinded, independent fashion.

RESULTS

Two solid lesions (mean size 9 mm) and nine cysts ≥10 mm (mean size 17 mm) were detected in nine HRI (6%). Both solid lesions were detected by EUS only and proved to be a stage I PDAC and a multifocal pancreatic intraepithelial neoplasia 2. Of the nine cysts ≥10 mm, six were detected by both imaging techniques and three were detected by MRI only. The agreement between EUS and MRI for the detection of clinically relevant lesions was 55%. Of these clinically relevant lesions detected by both techniques, there was a good agreement for location and size.

CONCLUSIONS

EUS and/or MRI detected clinically relevant pancreatic lesions in 6% of HRI. Both imaging techniques were complementary rather than interchangeable: contrary to EUS, MRI was found to be very sensitive for the detection of cystic lesions of any size; MRI, however, might have some important limitations with regard to the timely detection of solid lesions.

A MicroRNA Panel in Pancreatic Cyst Fluid for the Risk Stratification of Pancreatic Cysts in a Prospective Cohort

A subset of pancreatic cystic neoplasms are regarded as precursor lesions of pancreatic cancer, but only a minority of all pancreatic cystic neoplasms will undergo malignant transformation. MicroRNAs are increasingly recognized as molecular targets in carcinogenesis. Previously, a 9-microRNA (miR) signature was suggested to discriminate between high risk and low risk pancreatic cystic neoplasm. In this study, we aimed to validate this 9-miR panel in a prospective cohort. Total miR was isolated from pancreatic cyst fluid and expression of miR18a, miR24, miR30a-3p, miR92a, miR99b, miR106b, miR142-3p, miR342-3p, and miR532-3p was analyzed by singleplex Taqman MicroRNA Assay. A total of 62 patient samples were analyzed. During follow-up, 24 (38.7%) patients underwent resection, of which 6 (9.7%) patients showed at least high grade dysplasia. A logistic regression model presented a “predicted risk” score which significantly differed between low and high risk cysts, either including all patients or only those with histological confirmation of diagnosis. Using a set cut-off of 50%, the sensitivity of the model for the total cohort was 10.0%, specificity 100.0%, positive predicted value 100.0%, negative predicted value 85.2%, and diagnostic accuracy of 85.5%. Thus, while observing a significant difference between low and high risk cysts, clinical implementation of this biomarker panel is as yet unlikely to be beneficial in the management of pancreatic cysts.

Spatial Patterns of Dissipative Polariton Solitons in Semiconductor Microcavities

We report propagating bound microcavity polariton soliton arrays consisting of multipeak structures either along (x) or perpendicular (y) to the direction of propagation. Soliton arrays of up to five solitons are observed, with the number of solitons controlled by the size and power of the triggering laser pulse. The breakup along the x direction occurs when the effective area of the trigger pulse exceeds the characteristic soliton size determined by polariton-polariton interactions. Narrowing of soliton emission in energy-momentum space indicates phase locking between adjacent solitons, consistent with numerical modeling which predicts stable multihump soliton solutions. In the y direction, the breakup originates from inhomogeneity across the wave front in the transverse direction which develops into a stable array only in the solitonic regime via phase-dependent interactions of propagating fronts.

Acoustically driven arrayed waveguide grating

We demonstrate compact tunable phased-array wavelength-division multiplexers driven by surface acoustic waves (SAWs) in the low GHz range. The devices comprise two couplers, which respectively split and combine the optical signal, linked by an array of single-mode waveguides (WGs). Two different layouts are presented, in which multi-mode interference couplers or free propagating regions were separately employed as couplers. The multiplexers operate on five equally distributed wavelength channels, with a spectral separation of 2 nm. A standing SAW modulates the refractive index of the arrayed WGs. Each wavelength component periodically switches paths between the output channel previously asigned by the design and the adjacent channels, at a fixed applied acoustic power. The devices were monolithically fabricated on (Al,Ga)As. A good agreement between theory and experiment is achieved.

Histological and Molecular Subclassification of Pancreatic and Nonpancreatic Periampullary Cancers: Implications for (Neo) Adjuvant Systemic Treatment

The benefit of adjuvant chemotherapy for resected pancreatic ductal adenocarcinoma (PDAC) has been confirmed in randomized controlled trials. For nonpancreatic periampullary cancers (NPPC) originating from the distal bile duct, duodenum, ampulla, or papilla of Vater, the role of adjuvant therapy remains largely unclear. This review describes methods for distinguishing PDAC from NPPC by means of readily available and recently developed molecular diagnostic methods. The difficulties of reliably determining the exact origin of these cancers pathologically also is discussed. The review also considers the possibility of unintentional inclusion of NPPC in the most important adjuvant trials on PDAC and the subsequent implications for interpretation of the results. The authors conclude that correct determination of the origin of periampullary cancers is essential for clinical management and should therefore be systematically incorporated into clinical practice and future studies.

Induction chemotherapy followed by surgery for advanced oesophageal cancer

BACKGROUND

Patients with locoregionally advanced oesophageal tumours or disputable distant metastases are referred for induction chemotherapy with the aim to downstage the tumour before an oesophagectomy is considered.

STUDY DESIGN

Patients who underwent induction chemotherapy between January 2005 and December 2012 were identified from an institutional database. Treatment plan was discussed in the multidisciplinary team. Response to chemotherapy was assessed by CT. Survival was calculated using the Kaplan Meier method. Uni- and multivariable analyses were performed to identify prognostic factors for survival.

RESULTS

In total 124 patients received induction chemotherapy mainly for locoregionally advanced disease (n = 80). Surgery was withheld in 35 patients because of progressive disease (n = 16) and persistent unresectability (n = 19). The median overall survival of this group was 13 months (IQR: 8-19). The remaining 89 patients underwent surgery of which 13 still had unresectable tumour or distant metastases. Of the 76 patients that underwent an oesophagectomy, 50 patients had tumour free resection margins (66%) with an estimated 5-year survival of 37%. A positive resection margin (HR 4.148, 95% CI 2.298-7.488, p < 0.0001) was associated with a worse survival in univariable analysis, but only pathological lymph node status with increasing hazard ratio's (6.283-10.283, p = 0.001) remained significant after multivariable analysis.

CONCLUSION

Induction chemotherapy downstages the tumour and facilitates a radical oesophagectomy in patients with advanced oesophageal cancer. Pathological lymph node status is an independent prognostic factor for overall survival.

Human epidermal growth factor receptor 2 overexpression and amplification in endoscopic biopsies and resection specimens in esophageal and junctional adenocarcinoma

Human epidermal growth factor receptor 2 (HER2) is overexpressed in a subset of esophageal adenocarcinomas. Frequently, biopsy material is used for evaluation of HER2 status. The aim of the study was to determine if HER2 expression in preoperative endoscopic biopsies is representative for the entire tumor. Preoperative endoscopic biopsies and matched resection specimens were collected from 75 patients who underwent esophagectomy for esophageal adenocarcinoma. Immunohistochemical staining (IHC) on HER2 and dual-color in situ hybridization (ISH) were performed. HER2 status was determined by following a clinical algorithm, first determining HER2 overexpression on immunohistochemistry and, when equivocal (2+), determining HER2 amplification on ISH. Seventy-one of 75 (95%) biopsies and 69/75 (92%) resection specimens could be analyzed due to technical failure. HER2 positivity was seen in 18/71 (25%) biopsies and in 15/69 (22%) resection specimens. Overall, HER2 status in the biopsy was concordant with HER2 status in the resection specimen in 94% of cases. Interobserver agreement on IHC scoring for all three observers was 83% in biopsies and 85% in resection specimens. HER2 positivity was detected in 22% of esophageal adenocarcinomas. Although interobserver agreement was moderate, HER2 status of a primary tumor can be reliably determined based on the endoscopically obtained pretreatment biopsy.

High-temperature, continuous-wave operation of terahertz quantum-cascade lasers with metal-metal waveguides and third-order distributed feedback

Currently, different competing waveguide and resonator concepts exist for terahertz quantum-cascade lasers (THz QCLs). We examine the continuous-wave (cw) performance of THz QCLs with single-plasmon (SP) and metal-metal (MM) waveguides fabricated from the same wafer. While SP QCLs are superior in terms of output power, the maximum operating temperature for MM QCLs is typically much higher. For SP QCLs, we observed cw operation up to 73 K as compared to 129 K for narrow (≤ 15 μm) MM QCLs. In the latter case, single-mode operation and a narrow beam profile were achieved by applying third-order distributed-feedback gratings and contact pads which are optically insulated from the intended resonators. We present a quantitative analytic model for the beam profile, which is based on experimentally accessible parameters.

Effects of spin-dependent interactions on polarization of bright polariton solitons

We report on the spin properties of bright polariton solitons supported by an external pump to compensate losses. We observe robust circularly polarized solitons when a circularly polarized pump is applied, a result attributed to phase synchronization between nondegenerate TE and TM polarized polariton modes at high momenta. For the case of a linearly polarized pump, either σ+ or σ- circularly polarized bright solitons can be switched on in a controlled way by a σ+ or σ- writing beam, respectively. This feature arises directly from the widely differing interaction strengths between co- and cross-circularly polarized polaritons. In the case of orthogonally linearly polarized pump and writing beams, the soliton emission on average is found to be unpolarized, suggesting strong spatial evolution of the soliton polarization. The observed results are in agreement with theory, which predicts stable circularly polarized solitons and unstable linearly polarized solitons.

Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution

We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast "white light" supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

Follow-up of premalignant lesions in patients at risk for progression to gastric cancer

BACKGROUND AND STUDY AIMS

A recent international guideline recommends surveillance of premalignant gastric lesions for patients at risk of progression to gastric cancer. The aim of this study was to identify the role of the distribution and severity of premalignant lesions in risk categorization.

PATIENTS AND METHODS

Patients with a previous diagnosis of atrophic gastritis, intestinal metaplasia, or low grade dysplasia were invited for surveillance endoscopy with non-targeted biopsy sampling. Biopsy specimens were evaluated by pathologists (four general and one expert) using the Sydney and the operative link for gastric intestinal metaplasia (OLGIM) systems, and scores were compared using kappa statistics.

RESULTS

140 patients were included. In 37 % (95 % confidence interval [CI] 29 % - 45 %) the severity of premalignant lesions was less than at baseline, while 6 % (95 %CI 2 % - 10 %) showed progression to more severe lesions. Intestinal metaplasia in the corpus was most likely to progress to more than one location (57 %; 95 %CI 36 % - 76 %). The proportion of patients with multilocated premalignant lesions increased from 24 % at baseline to 31 % at surveillance (P = 0.014). Intestinal metaplasia was the premalignant lesion most frequently identified in subsequent endoscopies. Intestinal metaplasia regressed in 27 % compared with 44 % for atrophic gastritis and 100 % for low grade dysplasia. Interobserver agreement was excellent for intestinal metaplasia (k = 0.81), moderate for dysplasia (k = 0.42), and poor for atrophic gastritis (k < 0).

CONCLUSIONS

Premalignant gastric lesions found in the corpus have the highest risk of progression, especially intestinal metaplasia, which has excellent interobserver agreement. This supports the importance of intestinal metaplasia as marker for follow-up in patients with premalignant gastric lesions.

Exciton-polariton gap solitons in two-dimensional lattices

We report on the two-dimensional gap-soliton nature of exciton-polariton macroscopic coherent phases (PMCP) in a square lattice with a tunable amplitude. The resonantly excited PMCP forms close to the negative mass M point of the lattice band structure with energy within the lattice band gap and its wave function localized within a few lattice periods. The PMCPs are well described as gap solitons resulting from the interplay between repulsive polariton-polariton interactions and effective attractive forces due to the negative mass. The solitonic nature accounts for the reduction of the PMCP coherence length and optical excitation threshold with increasing lattice amplitude.

Synchronized photonic modulators driven by surface acoustic waves

Photonic modulators are one of the most important elements of integrated photonics. We have designed, fabricated, and characterized a tunable photonic modulator consisting of two 180°-dephased output waveguide channels, driven by a surface acoustic wave in the GHz frequency range built on (Al,Ga)As. Odd multiples of the fundamental driven frequency are enabled by adjusting the applied acoustic power. A good agreement between theory and experimental results is achieved. The device can be used as a building block for more complex integrated functionalities and can be implemented in several material platforms.

Electrical suppression of spin relaxation in GaAs(111)B quantum wells

Spin dephasing via the spin-orbit interaction (SOI) is a major mechanism limiting the electron spin lifetime in III-V zincblende quantum wells (QWs). The dephasing can be suppressed in GaAs(111) quantum wells by applying an electric field. The suppression has been attributed to the compensation of the intrinsic SOI associated with the bulk inversion asymmetry of the GaAs lattice by a structural induced asymmetry SOI term induced by an electric field. We provide direct experimental evidence for this mechanism by demonstrating the transition between the bulk inversion asymmetry-dominated to a structural induced asymmetry-dominated regime via photoluminescence measurements carried out over a wide range of applied fields. Spin lifetimes exceeding 100 ns are obtained near the compensating electric field, thus making GaAs(111) QWs excellent candidates for the electrical storage and manipulation of spins.

Preoperative chemoradiotherapy for esophageal or junctional cancer

BACKGROUND

The role of neoadjuvant chemoradiotherapy in the treatment of patients with esophageal or esophagogastric-junction cancer is not well established. We compared chemoradiotherapy followed by surgery with surgery alone in this patient population.

METHODS

We randomly assigned patients with resectable tumors to receive surgery alone or weekly administration of carboplatin (doses titrated to achieve an area under the curve of 2 mg per milliliter per minute) and paclitaxel (50 mg per square meter of body-surface area) for 5 weeks and concurrent radiotherapy (41.4 Gy in 23 fractions, 5 days per week), followed by surgery.

RESULTS

From March 2004 through December 2008, we enrolled 368 patients, 366 of whom were included in the analysis: 275 (75%) had adenocarcinoma, 84 (23%) had squamous-cell carcinoma, and 7 (2%) had large-cell undifferentiated carcinoma. Of the 366 patients, 178 were randomly assigned to chemoradiotherapy followed by surgery, and 188 to surgery alone. The most common major hematologic toxic effects in the chemoradiotherapy-surgery group were leukopenia (6%) and neutropenia (2%); the most common major nonhematologic toxic effects were anorexia (5%) and fatigue (3%). Complete resection with no tumor within 1 mm of the resection margins (R0) was achieved in 92% of patients in the chemoradiotherapy-surgery group versus 69% in the surgery group (P<0.001). A pathological complete response was achieved in 47 of 161 patients (29%) who underwent resection after chemoradiotherapy. Postoperative complications were similar in the two treatment groups, and in-hospital mortality was 4% in both. Median overall survival was 49.4 months in the chemoradiotherapy-surgery group versus 24.0 months in the surgery group. Overall survival was significantly better in the chemoradiotherapy-surgery group (hazard ratio, 0.657; 95% confidence interval, 0.495 to 0.871; P=0.003).

CONCLUSIONS

Preoperative chemoradiotherapy improved survival among patients with potentially curable esophageal or esophagogastric-junction cancer. The regimen was associated with acceptable adverse-event rates. (Funded by the Dutch Cancer Foundation [KWF Kankerbestrijding]; Netherlands Trial Register number, NTR487.).

Lateral distributed-feedback gratings for single-mode, high-power terahertz quantum-cascade lasers

We report on terahertz quantum-cascade lasers (THz QCLs) based on first-order lateral distributed-feedback (lDFB) gratings, which exhibit continuous-wave operation, high output powers (>8 mW), and single-mode emission at 3.3-3.4 THz. A general method is presented to determine the coupling coefficients of lateral gratings in terms of the coupled-mode theory, which demonstrates that large coupling strengths are obtained in the presence of corrugated metal layers. The experimental spectra are in agreement with simulations of the lDFB cavities, which take into account the reflective end facets.

Role of acid suppression in the development and progression of dysplasia in patients with Barrett's esophagus

Barrett's esophagus (BE) usually develops in patients with gastroesophageal reflux disease and therefore it has been suggested that esophageal acid exposure plays an import role in the initiation of BE and its progression towards esophageal adenocarcinoma (EAC). The mechanisms whereby acid exposure causes BE are not completely revealed and the potential role of esophageal acid exposure in carcinogenesis is unclear as well. Since acid exposure is thought to play an important role in the progression of BE, therapies aimed at preventing the development of EAC have primarily focused on pharmacological and surgical acid suppression. In clinical practice, acid suppression is effective in relieving reflux symptoms and decreases esophageal acid exposure in most patients. However, in some individuals, pathological acid exposure persists and these patients continue to be at risk for developing dysplasia or EAC. To date, published trials suggest that acid suppression is able to prevent the development and progression of dysplasia in patients with BE, but definite and compelling proof is still lacking. This article reviews the mechanisms of acid-induced carcinogenesis in BE and the role of acid suppression in the prevention of neoplastic progression.

[Carcinoma in situ of the testis: predisposition, evolution and early detection]

Carcinoma in situ (CIS), also known as intratubular germ cell neoplasia unclassified, is the common obligate precursor lesion of malignant testicular seminomatous and non-seminomatous germ cell tumors (GCT), which show a steadily increasing incidence in Europe. Although GCT is a potentially curable cancer with excellent prognosis even in patients with organ metastasis, many patients suffer from chemotherapy-associated effects and some develop a secondary (non-germ cell) malignancy. Recently, genome-wide association studies revealed genetic predispositions linked to six genes (KITL, SPRY4, BAK1, TERT, ATF7IP, DMRT1). Exposure to environmental factors was also linked to increased prevalence of testicular dysgenesis and CIS/GCT by the action of hormone disruptors on embryonal gonadal tissue during pregnancy. By unknown mechanisms these genetic and environmental factors might create a disturbed microenvironment in the fetal testis leading to survival of embryonic germ cells and subsequent malignant transformation might result in CIS. Molecular pathways involved in this process include activated cKIT pathway and LIN28 associated deregulation of miRNA targets. The challenge for the future is to identify high risk patients prior to invasive GCT, to develop non-invasive tests for detection of CIS on seminal material and elucidate the precise role of the microenvironment in CIS initiation.

Expression and interdependencies of pluripotency factors LIN28, OCT3/4, NANOG and SOX2 in human testicular germ cells and tumours of the testis

OCT3/4, NANOG, SOX2 and, most recently, LIN28 have been identified as key regulators of pluripotency in mammalian embryonic and induced stem cells, and are proven to be crucial for generation of the mouse germ-cell lineage. These factors are a hallmark of certain histological types of germ-cell tumours (GCTs). Here, we report novel information on the temporal and spatial expression pattern of LIN28 during normal human male germ-cell development as well as various types of GCTs. To investigate LIN28 expression, immunohistochemical analyses and quantitative proximity ligation assay-based TaqMan protein assays were applied on snap-frozen and formalin-fixed, paraffin-embedded samples as well as representative cell lines. LIN28 was found in primordial germ cells, gonocytes and pre-spermatogonia, in contrast to OCT3/4 and NANOG, which were found only in the first two stages. LIN28 was also found in all precursor lesions (carcinoma in situ and gonadoblastoma) of type II GCTs, as well as the invasive components seminoma and the non-seminomatous elements embryonal carcinoma and yolk sac tumour. Choriocarcinoma showed a heterogeneous pattern, while teratomas and spermatocytic seminomas (type III GCTs) were negative. This expression pattern suggests that LIN28 is associated with malignant behaviour of type II GCTs. Cell line experiments involving siRNA knockdown of LIN28, OCT3/4 and SOX2 showed that LIN28 plays a role in the maintenance of the undifferentiated state of both seminoma and embryonal carcinoma, closely linked to, and likely upstream of OCT3/4 and NANOG. In conclusion, LIN28 regulates the differentiation status of seminoma and embryonal carcinoma and is likely to play a related role in normal human germ-cell development.

Dissecting the molecular pathways of (testicular) germ cell tumour pathogenesis; from initiation to treatment-resistance

Human type II germ cell tumours (GCTs) originate from an embryonic germ cell, either as a primordial germ cell or gonocyte. This start determines the biological as well as clinical characteristics of this type of cancer, amongst others their totipotency as well as their overall (exceptional) sensitivity to DNA damaging agents. The histology of the precursor lesion, either carcinoma in situ or gonadoblastoma, depends on the level of testicularization (i.e. testis formation) of the gonad. The impact of either intrinsic (genetic) - and environmental factors involved in the pathogenesis is demonstrated by disorders of sex development as well as testicular dysgenesis syndrome as risk factors, including cryptorchidism, hypospadias and disturbed fertility as parameters. This knowledge allows identification of individuals at risk for development of this type of cancer, being a population of interest for screening. Factors known to regulate pluripotency during embryogenesis are proven to be of diagnostic value for type II GCTs, including OCT3/4, even applicable for non-invasive screening. In addition, presence of stem cell factor, also known as KITLG, allows distinction between delayed matured germ cells and the earliest stages of malignant transformation. This is of special interest because of the identified association between development of type II GCTs of the testis and a limited number of single nucleotide polymorphisms, including some likely related to KITL. Transition from the precursor lesion to an invasive cancer is associated with gain of the short arm of chromosome 12, in which multiple genes might be involved, including KRAS2 and possibly NANOG (pseudogenes). While most precursor lesions will progress to an invasive cancer, only a limited number of cancers will develop treatment resistance. Putative explanatory mechanisms are identified, including presence of microsatellite instability, BRAF mutations, apoptosis suppression and p21 sub-cellular localization. It remains to be investigated how these different pathways integrate to each other and how informative they are at the patient-individual level. Further understanding will allow development of more targeted treatment, which will benefit quality of life of these young cancer patients.

The prevalence of premalignant gastric lesions in asymptomatic patients: predicting the future incidence of gastric cancer

BACKGROUND

Helicobacter pylori is the main risk-factor for gastric cancer through a cascade from gastritis through atrophic gastritis (AG), intestinal metaplasia (IM), dysplasia (DYS) to malignancy. The presence of these lesions in the general population predicts the gastric cancer incidence in the coming decades. Prevalence data are mostly obtained from serological studies and endoscopy data in symptomatic patients.

AIM

To investigate the prevalence of H. pylori infection and its related gastric changes in asymptomatic subjects.

METHODS

383 Patients undergoing routine colonoscopy were included. All subjects underwent upper GI endoscopy and completed the Gastrointestinal Symptom Rating Scale (GSRS). Biopsies were taken from antrum and corpus.

RESULTS

H. pylori infection was present in 22%. Non-Caucasian subjects had a significantly higher H. pylori prevalence (p < 0.001). AG, IM and DYS were together found in 9.3% of subjects. Subjects with AG, IM or DYS were significantly older (p < 0.001). No differences were found with respect to gender, presence of GI symptoms as scored by GSRS, lifestyle and medication use.

CONCLUSIONS

The prevalence of premalignant gastric lesions is considerable in general Western population with increasing age as the main risk factor. One time screening for premalignant lesions at the age of 60 years is a reasonable strategy since the numbers found imply that gastric cancer will remain a prevalent disease.

A short course of corticosteroids prior to surveillance colonoscopy to decrease mucosal inflammation in inflammatory bowel disease patients: results from a randomized controlled trial

BACKGROUND

Inflammation is a known pitfall of surveillance colonoscopy for inflammatory bowel disease (IBD) as it is difficult to differentiate between inflammation and true dysplasia. This randomized controlled trial assessed the effectiveness of a low dose of corticosteroids prior to surveillance colonoscopy to decrease mucosal inflammation.

METHODS

IBD-patients scheduled for surveillance colonoscopy between July 2008-January 2010 were eligible to participate. Patients were randomized to either two weeks daily 20mg prednisone and calcium plus vitamin D prior to surveillance colonoscopy or no treatment. All biopsies were reviewed by an expert gastrointestinal pathologist who was blinded for medication-use. Statistics were performed using chi-square tests, non-parametric tests and binary logistic regression.

RESULTS

Sixty patients (M/F 30/30, UC/CD 31/29) participated: 31 (52%) in the treatment arm and 29 (48%) in the control group. In the treatment arm, 247 biopsies were scored against 262 in the control group. In the treatment arm 27 out of 247 biopsies (10.9%) had a score >1 on the Geboes scale, against 50 out of 262 biopsies (19.1%) in the control group, p=0.013. In total, 58% of the treatment arm against 66% of the control group had endoscopic or histological mucosal inflammation (p=0.6). There was a trend for patients in the treatment arm to have less severe inflammation compared with the control group, however this was not significant (p=0.12).

CONCLUSIONS

In our cohort, a short course of corticosteroids decreases the overall histological disease activity in individual biopsies without major side-effects. Moreover, there is a trend for corticosteroids to decrease the maximum severity of both endoscopic and histological disease activity per patient.

Polariton condensation in dynamic acoustic lattices

We demonstrate that the tunable potential introduced by a surface acoustic wave on a homogeneous polariton condensate leads to fragmentation of the condensate into an array of wires which move with the acoustic velocity. Reduction of the spatial coherence of the condensate emission along the surface acoustic wave direction is attributed to the suppression of coupling between the spatially modulated condensates. Interparticle interactions observed at high polariton densities screen the acoustic potential, partially reversing its effect on spatial coherence.

Effect of interactions on vortices in a nonequilibrium polariton condensate

We demonstrate the creation of vortices in a macroscopically occupied polariton state formed in a semiconductor microcavity. A weak external laser beam carrying orbital angular momentum (OAM) is used to imprint a vortex on the condensate arising from the polariton optical parametric oscillator (OPO). The vortex core radius is found to decrease with increasing pump power, and is determined by polariton-polariton interactions. As a result of OAM conservation in the parametric scattering process, the excitation consists of a vortex in the signal and a corresponding antivortex in the idler of the OPO. The experimental results are in good agreement with a theoretical model of a vortex in the polariton OPO.

Fixed Size of Enlarged Calcified Lymph Nodes in Esophageal Adenocarcinoma despite Complete Remission

Untreated malignant lymph nodes that are calcified are rare. Publications on such calcifications are restricted to case reports. We present a case of calcified lymph nodes in a patient with adenocarcinoma of the gastroesophageal junction that seemed to be nonresponsive to induction chemotherapy, as they did not decrease in size. However, on pathological examination of the resected lymph nodes no vital tumor cells could be detected anymore. Therefore, we hypothesize that a calcified lymph node is unable to shrink, even after adequate remission on induction chemotherapy. This should be taken into account when clinical decision-making depends on the change in size of an enlarged, calcified lymph node as a measure of treatment effect.

[Molecular pathology of testicular germ cell tumors: an update]

Germ cell tumors (GCT) comprise a heterogeneous group of benign and malignant tumors. Based on their different biological characteristics and their origin, five types of GCT are classified. Among these, malignant seminomatous and non-seminomatous GCT in males and females are designated as type II GCT. They occur most frequently as malignant testicular GCTs. Many characteristics of type II GCT can be linked to embryonic stem cells. Intratubular germ cell neoplasia, unclassified (IGCNU) is the precursor of type II GCT and derives from undifferentiated germ cells, gonocytes, which persist in the newborn testis and escape the normal differentiation process. It is suggested that Exon-17-activated mutations of the receptor tyrosine kinase, c-KIT, occur early in germ cell development and that gonocytes with an activated c-KIT receptor are restricted in their differentiation, thereby escaping normal development. New diagnostic markers for neoplastic germ cells, including OCT3/4 and AP-2gamma, are specifically detected in IGCNU, seminomas and embryonal carcinomas and are helpful in the differentiation of type II GCT from other malignant tumors.

[Aggressive course of a malignant alveolar soft tissue sarcoma]

Alveolar soft part sarcoma is a rare soft tissue tumor. Most patients who are affected by this sarcoma are between 15 and 35 years old. The tumor is characterized by its uncommon location of metastasis. Publications concerning this sarcoma subform are rare and the best therapeutic procedure is not yet clear. Surgical excision, radiation and chemotherapy are performed, whereas complete surgical excision achieves the best results in long-term follow-up. We report a patient's history who rapidly died of his sickness despite the low initial tumor stage.

Prostate cancer tissue is masked by bicalutamide: a case report

Prostate cancer is the most common malignant tumor in men. Recently, a slightly decreased frequency of margin positivity following neoadjuvant bicalutamide treatment due to tumor shrinkage was reported. Trials investigating other anti-androgens in the past also reported lower frequencies of surgical margin positivity, but patients outcome has not improved. In this case, local recurrence was confirmed by needle biopsy in a patient five years following radical prostatectomy for prostate adenocarcinoma. After therapy with 50 mg bicalutamide for a month, the tumour was resected. Despite of detailed histological work-up and immunohistochemistry cancer suspicious lesions were not found. We think that bicalutamide may be capable of masking prostate cancer cells.

[Primitive neuroectodermal tumor of the kidney]

Primitive neuroectodermal Tumor (PNET) is a rare malignant tumor of young adult. Patients often present with the classical trias of renal cancer (pain, haematuria, palpable tumor). Specific radiological signs are missing, and therefore a PNET is often diagnosed postoperatively. It is characterized by the expression of MIC2, neural markers (Vimentin, S-100, Synaptophysin) and EWS/FLI1-translocation. The tumor is often diagnosed in advanced stage, and prognosis is poor despite of multimodal treatment including radical nephrectomy, polychemotherapy (vincristine, adriamycin, cyclophosphamid, etoposide, ifosfamide) and radiation in case of metastases or incomplete resection of primary tumor. We represent two cases of metastatic renal PNET in a 28- and 39-year-old patient. Due to the multimodal treatment a partial and a complete remission was achieved, respectively.