Factors Influencing the Success of In Vivo Sentinel Lymph Node Procedure in Colon Cancer Patients: Swiss Prospective, Multicenter Study Sentinel Lymph Node Procedure in Colon Cancer

Background: The sentinel lymph node (SLN) procedure has the potential to provide relevant improvement in nodal staging in colon cancer patients. However, there remains room for improvement for SLN identification and sensitivity. Therefore, the objective of the present investigation was to analyze factors influencing the success of the SLN procedure in colon cancer patients. Methods: One hundred seventy-four consecutive colon cancer patients were prospectively enrolled in this multicenter study and underwent in vivo SLN procedure with isosulfan blue 1% followed by open standard oncologic colon resection. Several patient-, tumor-, and procedure-related factors possibly influencing the SLN identification and sensitivity were analyzed. Results: Sentinel lymph node identification rate and accuracy were 89.1 and 83.9%, respectively. Successful identification of SLN was significantly associated with the intraoperative visualization of blue lymphatic vessels (p<0.001) and with female gender (p=0.024). True positive SLN results were significantly associated with higher numbers of SLN (p=0.026) and with pN2 stage (p=0.004). There was a trend toward better sensitivity in patients with lower body mass index (BMI) (p=0.050). Conclusions: The success of the SLN procedure in colon cancer patients depends on both procedure-related factors (intraoperative visualization of blue lymphatic vessels, high number of SLN identified) and patient factors (gender, BMI). While patient factors can not be influenced, intraoperative visualization of blue lymphatics and identification of high numbers of SLN are key for a successful SLN procedur

Tissue Banking in a Regional Hospital: A Promising Future Concept? First Report on Fresh Frozen Tissue Banking in a Hospital Without an Integrated Institute of Pathology

Background: Vital tissue provided by fresh frozen tissue banking is often required for genetic tumor profiling and tailored therapies. However, the potential patient benefits of fresh frozen tissue banking are currently limited to university hospitals. The objective of the present pilot study—the first one in the literature—was to evaluate whether fresh frozen tissue banking is feasible in a regional hospital without an integrated institute of pathology. Methods: Patients with resectable breast and colon cancer were included in this prospective study. Both malignant and healthy tissue were sampled using isopentan-based snap-freezing 1h after tumor resection and stored at −80°C before transfer to the main tissue bank of a University institute of pathology. Results: The initial costs to set up tissue banking were 35,662 US$. Furthermore, the running costs are 1,250 US$ yearly. During the first 13months, 43 samples (nine samples of breast cancer and 34 samples of colon cancer) were collected from 41 patients. Based on the pathology reports, there was no interference with standard histopathologic analyses due to the sample collection. Conclusions: This is the first report in the literature providing evidence that tissue banking in a regional hospital without an integrated institute of pathology is feasible. The interesting findings of the present pilot study must be confirmed by larger investigation

Sultr4;1 mutant seeds of Arabidopsis have an enhanced sulphate content and modified proteome suggesting metabolic adaptations to altered sulphate compartmentalization

<p>Abstract</p> <p>Background</p> <p>Sulphur is an essential macronutrient needed for the synthesis of many cellular components. Sulphur containing amino acids and stress response-related compounds, such as glutathione, are derived from reduction of root-absorbed sulphate. Sulphate distribution in cell compartments necessitates specific transport systems. The low-affinity sulphate transporters SULTR4;1 and SULTR4;2 have been localized to the vacuolar membrane, where they may facilitate sulphate efflux from the vacuole.</p> <p>Results</p> <p>In the present study, we demonstrated that the <it>Sultr4;1 </it>gene is expressed in developing Arabidopsis seeds to a level over 10-fold higher than the <it>Sultr4;2 </it>gene. A characterization of dry mature seeds from a <it>Sultr4;1 </it>T-DNA mutant revealed a higher sulphate content, implying a function for this transporter in developing seeds. A fine dissection of the <it>Sultr4;1 </it>seed proteome identified 29 spots whose abundance varied compared to wild-type. Specific metabolic features characteristic of an adaptive response were revealed, such as an up-accumulation of various proteins involved in sugar metabolism and in detoxification processes.</p> <p>Conclusions</p> <p>This study revealed a role for SULTR4;1 in determining sulphate content of mature Arabidopsis seeds. Moreover, the adaptive response of <it>sultr4;1 </it>mutant seeds as revealed by proteomics suggests a function of SULTR4;1 in redox homeostasis, a mechanism that has to be tightly controlled during development of orthodox seeds.</p

Mammotome: Less Invasive than ABBI with Similar Accuracy for Early Breast Cancer Detection

We performed a prospective analysis of two consecutive biopsy cohorts investigated by the same team to compare the Mammotome system with the ABBI procedure. From April 1997 to August 2003 a series of 413 nonpalpable mammographic lesions in 387 women (median age 56 years, range 30-84 years) were stereotactically biopsied in the University Hospital of Basel, Switzerland. Until October 1999 the ABBI system was applied exclusively, it was subsequently superseded by the Mammotome device in our clinic. Main outcome measures were accuracy, technical demand, and morbidity. Sensitivity (97.3%/96.8%), negative predictive value (99.2%/98.7%), and diagnostic accuracy (99.4%/99.1%) regarding the detection of malignancy were excellent for both techniques (ABBI/Mammotome). The Mammotome procedure was faster and less invasive, thus causing significantly less morbidity. The larger specimen obtained by the ABBI procedure resulted in more detailed histology. In conclusion, recommend the Mammotome system as the method of choice for detecting nonpalpable early breast cance

The Value of Sentinel Lymph Node Mapping for the Staging of Node-Negative Colon Cancer

Objectives: Mediation analysis to assess the protective impact of sentinel lymph node (SLN) mapping on prognosis and survival of patients with colon cancer through a more precise evaluation of the lymph node (LN) status. Background: Up to 20% of patients with node-negative colon cancer develop disease recurrence. Conventional histopathological LN examination may be limited in describing the real metastatic burden of LN. Methods: Data of 312 patients with stage I & II colon cancer was collected prospectively. Patients were either staged using intraoperative SLN mapping with multilevel sectioning and immunohistochemical staining of the SLN or conventional techniques. The value of the SLN mapping for the detection of truly node-negative patients was assessed using Cox regression and mediation analysis. Results: SLN mapping was performed in 143 patients. Disease recurrence was observed in 13 (9.1%) patients staged with SLN mapping and in 27 (16%) staged conventionally. Five-year overall survival (OS) rate was 82.7% (95% confidence interval [CI], 76.5–89.4%) with SLN mapping compared with 65.8% (95% CI, 58.8–73.7%). Five-year cancer-specific survival (CSS) was 95.1% (95% CI, 91.3–99.0%) with SLN mapping compared with 92.5% (95% CI, 88.0–97.2%). Node-negative staging with SLN mapping was associated with significantly better OS (hazard ratio [HR], 0.64; 95% CI, 0.56–0.72; P < 0.001) and CSS (HR, 0.49; 95% CI, 0.39–0.61; P < 0.001) in multivariate analysis. Mediation analysis confirmed a direct protective effect of SLN mapping on OS (HR, 0.78; 95% CI, 0.52–0.96; P < 0.01) and disease-free survival (DFS) (HR, 0.75; 95% CI, 0.48–0.89; P < 0.01). Conclusions: Staging performed by SLN mapping with multilevel sectioning provides more accurate results than conventional staging. The observed clinically relevant and statistically significant benefit in OS and DFS is explained by a more accurate detection of positive LN by SLN mapping

Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer—a propensity score analysis

Purpose Nodal status in colorectal cancer (CRC) is an important prognostic factor, and adequate lymph node (LN) staging is crucial. Whether the number of resected and analysed LN has a direct impact on overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) is much discussed. Guidelines request a minimum number of 12 LN to be analysed. Whether that threshold marks a prognostic relevant cut-off remains unknown. Methods Patients operated for stage I–III CRC were identified from a prospectively maintained database. The impact of the number of analysed LN on OS, CSS and DFS was assessed using Cox regression and propensity score analysis. Results Of the 687 patients, 81.8% had ≥ 12 LN resected and analysed. Median LN yield was 17.0 (IQR 13.0–23.0). Resection and analysis of ≥ 12 LN was associated with improved OS (HR = 0.73, 95% CI: 0.56–0.95, p = 0.033), CSS (HR 0.52, 95% CI: 0.31–0.85, p = 0.030) and DFS (HR = 0.73, 95% CI: 0.57–0.95, p = 0.030) in multivariate Cox analysis. After adjusting for biasing factors with propensity score matching, resection of ≥ 12 LN was significantly associated with improved OS (HR = 0.59; 95% CI: 0.43–0.81; p = 0.002), CSS (HR = 0.34; 95% CI: 0.20–0.60; p < 0.001) and DFS (HR = 0.55; 95% CI: 0.41–0.74; p < 0.001) compared to patients with < 12 LN. Conclusion Eliminating biasing factors by a propensity score matching analysis underlines the prognostic importance of the number of analysed LN. The set threshold marks the minimum number of required LN but nevertheless represents a cut-off regarding outcome in stage I–III CRC. This analysis therefore highlights the significance and importance of adherence to surgical oncological standards

Concerted transformation of a hyper-paused transcription complex and its reinforcing protein

RfaH, a paralog of the universally conserved NusG, binds to RNA polymerases (RNAP) and ribosomes to activate expression of virulence genes. In free, autoinhibited RfaH, an α-helical KOW domain sequesters the RNAP-binding site. Upon recruitment to RNAP paused at an ops site, KOW is released and refolds into a β-barrel, which binds the ribosome. Here, we report structures of ops-paused transcription elongation complexes alone and bound to the autoinhibited and activated RfaH, which reveal swiveled, pre-translocated pause states stabilized by an ops hairpin in the non-template DNA. Autoinhibited RfaH binds and twists the ops hairpin, expanding the RNA:DNA hybrid to 11 base pairs and triggering the KOW release. Once activated, RfaH hyper-stabilizes the pause, which thus requires anti-backtracking factors for escape. Our results suggest that the entire RfaH cycle is solely determined by the ops and RfaH sequences and provide insights into mechanisms of recruitment and metamorphosis of NusG homologs across all life

Leveraging genomic annotations and pleiotropic enrichment for improved replication rates in schizophrenia GWAS

Most of the genetic architecture of schizophrenia (SCZ) has not yet been identified. Here, we apply a novel statistical algorithm called Covariate-Modulated Mixture Modeling (CM3), which incorporates auxiliary information (heterozygosity, total linkage disequilibrium, genomic annotations, pleiotropy) for each single nucleotide polymorphism (SNP) to enable more accurate estimation of replication probabilities, conditional on the observed test statistic (“z-score”) of the SNP. We use a multiple logistic regression on z-scores to combine information from auxiliary information to derive a “relative enrichment score” for each SNP. For each stratum of these relative enrichment scores, we obtain nonparametric estimates of posterior expected test statistics and replication probabilities as a function of discovery z-scores, using a resampling-based approach that repeatedly and randomly partitions meta-analysis sub-studies into training and replication samples. We fit a scale mixture of two Gaussians model to each stratum, obtaining parameter estimates that minimize the sum of squared differences of the scale-mixture model with the stratified nonparametric estimates. We apply this approach to the recent genome-wide association study (GWAS) of SCZ (n = 82,315), obtaining a good fit between the model-based and observed effect sizes and replication probabilities. We observed that SNPs with low enrichment scores replicate with a lower probability than SNPs with high enrichment scores even when both they are genome-wide significant (p < 5x10-8). There were 693 and 219 independent loci with model-based replication rates ≥80% and ≥90%, respectively. Compared to analyses not incorporating relative enrichment scores, CM3 increased out-of-sample yield for SNPs that replicate at a given rate. This demonstrates that replication probabilities can be more accurately estimated using prior enrichment information with CM3