Biofouling control in a membrane filtration system by a newly isolated novel quorum quenching bacterium, Bacillus methylotrophicus sp. WY

A newly isolated QQ bacterium, Bacillus methylotrophicus strain WY substantially enhanced the membrane performance by reducing the rate of biofouling.

Abstract 3589: Validation of the role of circulating tumor DNA (ctDNA) in tracking mechanisms of resistance to anti-EGFR monoclonal antibodies (AE-mABs): preliminary results of the PROSPECT-C prospective trial

Background: AE-mABs (cetuximab and/or panitumumab) have been approved for the treatment of RAS wild-type (WT) metastatic colorectal cancer (mCRC) patients (pts). Indeed, previous studies have identified mutations (MTs)/amplifications in RAS/RAF/MEK kinase pathway as the main genetic events promoting primary and acquired resistance to these mABs. RAS status is frequently established on archival material, as tumour re-biopsy may not be always feasible. PROSPECT-C is a prospective trial aiming to define novel and known mechanisms of resistance to AE-mABs by obtaining repeated biopsies and sequential bloods from pts receiving AE-mABs for chemo-refractory mCRC.

Here we present the preliminary results of the PROSPECT-C liquid biopsy study where the goals were to: 1) confirm the ability of ctDNA to determine RAS status prior to treatment; 2) determine any discordance of RAS status between archival material and ctDNA; 3) confirm the ability of ctDNA to track emerging MTs in the RAS pathway.

Materials and Methods: Plasma was collected at baseline (BL), every 4 weeks and at progression (PD). ctDNA was isolated using the QIAamp Circulating Nucleic Acid Kit (Qiagen) and analyzed by digital droplet PCR (QX200 Bio-Rad) for MTs in KRAS-G12D, KRAS-G13D, KRAS-G12V, KRAS-Q61HA>T, KRAS-Q61HA>C, and BRAF-V600E. In the next steps, plasma samples with no MTs in the first series of hotspots will be tested for the remaining KRAS hotspots, NRAS, EGFR, PIK3CA MTs and KRAS, c-MET and HER-2 amplifications (Data to be presented).

Results: Twenty-four pts (all treated with AE-mAB monotherapy) with KRAS WT tumors (from archival tissue) have been treated on this ongoing study; 16/24 had ctDNA analysis (mean age 62 years, 62.5% males) so far. All pts were heavily pre-treated; 58.3%, 31.3% and 12.5% received 2, 3 and 4 lines of prior therapies respectively. Of 15 pts with BL samples, 5 had MTs at BL; 2 with KRAS-G12D, 1 with KRAS Q61HA>T and 2 pts with BRAF-V600E (in the latter case concordance was found with the archival material). Best response was found to be PD in 4/5 pts and stable disease in 1/5pt with BL MTs; 2 with BRAF MTs progressed in <2 months (mo). The median progression free survival (PFS) for pts with BL MTs was 1.8 mo. Five pts with no MT at BL developed one or more MTs later; those included 4 with KRAS-G12D, 3 with KRAS-G13D and 2 with KRASQ61HA>T (median PFS = 4.8 mo). 3/15 (20%) pts showed discordance in RAS MTs between archival material (WT) and baseline bloods (MT); all of them progressed within 3 mo.

Conclusions: Liquid biopsies can be a useful tool in determining and tracking RAS MTs in pts undergoing anti-EGFR therapy for mCRC. ctDNA analysis to assess RAS mutational status prior to receiving AE-mABs in our series showed 20% discordance between the archival solid and BL liquid biopsies, which may account for resistance to these therapies.

Citation Format: Khurum Khan, George Vlachogianis, David Cunningham, Jens Hahne, Mahnaz Darvish-Damavandi, Sarah Barton, Francesco Trevisani, Giulia Mentrast, Clare Peckitt, Andrea Lampis, Chiara Braconi, Nasir Khan, Ruwaida Begum, Naureen Starling, Sheela Rao, David Watkins, Annette Bryant, Ian Chau, Nicola Valeri. Validation of the role of circulating tumor DNA (ctDNA) in tracking mechanisms of resistance to anti-EGFR monoclonal antibodies (AE-mABs): preliminary results of the PROSPECT-C prospective trial. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3589. doi:10.1158/1538-7445.AM2015-3589

Spectacles in Stomach: A Case of Successful Endoscopic Removal

Ingestion of foreign bodies is a common reason for emergency visit. The ingested objects include batteries, needles, dentures, coins, sharps etc. Radiolucency and the length of the objects are important factors that affect their management. Long objects over 10 cm are less likely to pass through the duodenal curve. Sharp object that is not retrieved at the earliest may penetrate the wall and cause complications. We present here a challenging case of a middle aged psychiatric patient who swallowed long and sharp arms of her spectacles that were successfully retrieved endoscopically.

Antitumor activity in RAS-driven tumors by blocking AKT and MEK

PURPOSE

KRAS is the most commonly mutated oncogene in human tumors. KRAS-mutant cells may exhibit resistance to the allosteric MEK1/2 inhibitor selumetinib (AZD6244; ARRY-142886) and allosteric AKT inhibitors (such as MK-2206), the combination of which may overcome resistance to both monotherapies.

EXPERIMENTAL DESIGN

We conducted a dose/schedule-finding study evaluating MK-2206 and selumetinib in patients with advanced treatment-refractory solid tumors. Recommended dosing schedules were defined as MK-2206 at 135 mg weekly and selumetinib at 100 mg once daily.

RESULTS

Grade 3 rash was the most common dose-limiting toxicity (DLT); other DLTs included grade 4 lipase increase, grade 3 stomatitis, diarrhea, and fatigue, and grade 3 and grade 2 retinal pigment epithelium detachment. There were no meaningful pharmacokinetic drug-drug interactions. Clinical antitumor activity included RECIST 1.0-confirmed partial responses in non-small cell lung cancer and low-grade ovarian carcinoma.

CONCLUSION

Responses in KRAS-mutant cancers were generally durable. Clinical cotargeting of MEK and AKT signaling may be an important therapeutic strategy in KRAS-driven human malignancies (Trial NCT number NCT01021748).

New digital technologies for the surveillance of infectious diseases at mass gathering events

Outbreaks of infectious diseases at mass gatherings can strain the health system of the host region and pose a threat to local and global health. In addition to strengthening existing surveillance systems, most host nations also use novel technologies to assess disease risk and augment traditional surveillance approaches. We review novel approaches to disease surveillance using the Internet, mobile phone applications, and wireless sensor networks. These novel approaches to disease surveillance can result in prompt detection.

Prognostic factors and treatment outcomes in patients with Small Bowel Adenocarcinoma (SBA): the Royal Marsden Hospital (RMH) experience

Background

SBA is a rare tumour which carries a poor prognosis. Very few data on prognostic factors and treatment outcomes are available. We conducted a retrospective analysis of patients treated for SBA at our institution.

Methods

Clinico-pathological characteristics, treatments and outcomes of all the SBA patients treated consecutively from 1996 to 2011 were retrospectively collected. The prognostic value of baseline factors was assessed using the Cox regression model. The Kaplan-Meier method was used to estimate the survival outcomes.

Results

Eighty-four patients with SBA were treated during the study period. Of these, 48 presented with early stage SBA, while 36 had unresectable disease. All early stage SBA patients (58.3% males; median age, 59 years) underwent resection (R0 in 44/48) and 27 (56%) received adjuvant chemotherapy. Median relapse-free survival and overall survival (OS) were 31.1 months (95% CI: 8.0-54.3) and 42.9 (95% CI: 0–94.9), respectively. In univariate analyses, poor histological differentiation (p = 0.025) and lymphovascular invasion (p = 0.003) were prognostic for OS. In the group of patients with relapsed, unresectable or metastatic disease (n = 59), systemic chemotherapy was administered in 46 cases (78%). The response rate to first line chemotherapy was 50%. Median progression-free survival and OS were 8.8 (95% CI: 5.5-12.3) and 12.8 months (95% CI: 8.4-17.2), respectively. In univariate analyses, low albumin (p = 0.041) and high platelet count (p = 0.007) were prognostic for OS.

Conclusion

Prospective clinical trials are needed to inform the management of SBA patients. Prognostic factors evaluated in our series may be useful for patient stratification and treatment selection in future studies.

Reliability of Carotid Doppler performed in a dedicated Stroke Prevention Clinic

Introduction:

Doppler ultrasound (DUS) is used as a screening tool to assess internal carotid artery (ICA) disease. Recent reports suggest that the DUS may be inaccurate in over 28% of patients. We sought to evaluate the accuracy of DUS, when performed in a dedicated stroke prevention clinic (SPC).

Methods:

We retrospectively reviewed the charts of patients who had a DUS performed in our SPC, followed by conventional cerebral angiography. Three groups of patients were defined. Group 1 had DUS measured ICA stenosis of >50%; Group II had a DUS measured ICA stenosis of <50%; Group III had complete ICA occlusion on DUS.

Results:

Sixty-seven patients (69 arteries) were included in the study. There were 45 patients in Group I and based on the findings of cerebral angiography, carotid endarterectomy was considered inappropriate in only one patient. - a misclassification rate of 2.2% (95%CI: 0 – 6.5%). Group II consisted of 19 patients and on cerebral angiography, none of these patients had a stenosis of >50% - a misclassification rate of 0%. Group III consisted of five patients in whom DUS showed complete ICA occlusion. The angiogram confirmed the occlusion in all five patients – a misclassification rate of 0%. Overall, misclassification rate was 1.45% (95% CI: 0 - 4.3%).

Conclusions:

Doppler ultrasound when performed in a stroke prevention clinic (SPC), has a high accuracy in measuring ICA stenosis of >50%. Doppler ultrasound is reliable in detecting complete ICA occlusion and finally DUS is a reliable screening tool to rule out clinically significant ICA stenosis.

Phase I trial of cyclophosphamide as an immune modulator for optimizing oncolytic reovirus delivery to solid tumors

PURPOSE

Reovirus is a wild-type oncolytic virus that is ubiquitous in the environment; most patients are therefore preimmune. Therapeutic administration leads to an increase in neutralizing antireovirus antibody (NARA) titer. We hypothesized that if NARA limited reovirus antitumor activity, the effect might be attenuated by coadministration of cyclophosphamide.

EXPERIMENTAL DESIGN

In a phase I study, patients with advanced cancer received cyclophosphamide 3 days before intravenous reovirus serotype 3 Dearing (RT3D). The primary objective was to reduce the resulting rise in NARA titer. Cyclophosphamide dose was escalated from 25-1,000 mg/m(2) through nine cohorts; we aimed to define a well-tolerated immunomodulatory dose.

RESULTS

The combination was well tolerated in 36 patients, with grade 3/4 toxicities only seen at or above the maximum tolerated dose of cyclophosphamide, which was 800 mg/m(2) combined with reovirus. Immunosuppressive effect, defined as maintaining NARA titer rise below a predefined threshold, was observed in only one patient. Furthermore, despite expected myelosuppression seen at higher cyclophosphamide doses, no changes in T-cell subsets, including Tregs, occurred with dose escalation. Viable virus was detected in association with peripheral blood mononuclear cells (PBMC) from 14% of patients 10 days after the last RT3D injection, despite high plasma NARA titer, demonstrating a potential mechanism for prolonged evasion of neutralization by reovirus.

CONCLUSIONS

Coadministration of cyclophosphamide with reovirus is safe, but does not attenuate host antiviral responses. Alternative immunomodulation approaches should be explored, but association with PBMCs may allow reovirus to persist and evade even high levels of neutralizing antibodies.

Phase I trials in patients with relapsed, advanced upper gastrointestinal carcinomas: experience in a specialist unit

BACKGROUND

Conventional therapeutic options for patients with advanced upper gastrointestinal cancers (UGIC) are limited. Following first-line treatments, some patients are offered experimental therapies, including participation in Phase I trials. This study aims to describe the experience of UGIC patients treated in a dedicated Phase I unit.

METHODS

Patient, tumour and treatment characteristics, and clinical outcomes of UGIC patients treated consecutively at the Drug Development Unit, Royal Marsden Hospital, between 2005 and 2009, were recorded.

RESULTS

Ninety-six patients who previously received a median of 2 (range 1-4) lines of chemotherapies were treated in 30 Phase I trials. Of 81 evaluable patients, 9 achieved RECIST-objective response (11 %) with a 6-month clinical benefit rate of 14 %. Median progression free and overall survival were 7.7 weeks [95 %CI 7.7 (6.4-9.0)] and 19.1 weeks (95 %CI 17.5-20.8), respectively. Grade 3 or 4 toxicities were observed in 37 patients (39 %) and led to trial discontinuation in 9 (9 %); no toxicity-related death was recorded. In the multivariate analysis, serum albumin (<35 g/dl, HR2.0, p = 0.002) and lactate dehydrogenase (>192 μmol/l, HR1.7, p = 0.016) were prognostic of overall survival.

CONCLUSION

Phase I clinical trials can be considered a reasonable option in selected patients with relapsed UGIC. The use of objective prognosticators may improve selection and risk/benefit profile of patients.

Colorectal cancer with liver metastases: Neoadjuvant chemotherapy, surgical resection first or palliation alone?

Colorectal cancer (CRC) is one of the commonest cancers with 1.2 million new cases diagnosed each year in the world. It remains the fourth most common cause of cancer-related mortality in the world and accounts for > 600000 cancer-related deaths each year. There have been significant advances in treatment of metastatic CRC in last decade or so, due to availability of new active targeted agents and more aggressive approach towards the management of CRC, particularly with liver-only-metastases; however, these drugs work best when combined with conventional chemotherapy agents. Despite these advances, there is a lack of biomarkers to inform us about the accurate management of the patients with metastatic CRC. It is therefore imperative to carefully select the patients with comprehensive multi-disciplinary team input in order to optimise the management of these patients. In this review we will discuss various treatment options available in management of colorectal liver metastases with potential guidance on how and when to choose these options along with consideration on future directions in management of this disease.

Sentinel lymph node status in vulval cancer: systematic reviews of test accuracy and decision-analytic model-based economic evaluation

BACKGROUND

Vulval cancer causes 3-5% of all gynaecological malignancies and requires surgical removal and inguinofemoral lymphadenectomy (IFL). Complications affect > 50% of patients, including groin wound infection, lymphoedema and cellulitis. A sentinel lymph node (SLN) is the first groin node with the highest probability of malignancy. SLN biopsy would be useful if it could accurately identify patients in whom cancer has spread to the groin, without removing all groin nodes. SLNs can be identified by isosulfan blue dye and/or technetium-99 ((99m)Tc) radioactive tracer during lymphoscintigraphy. The blue dye/(99m)Tc procedure only detects SLN, not metastases - this requires histological examination, which can include ultrastaging and staining with conventional haematoxylin and eosin (H&E) or immunohistochemistry.

OBJECTIVES

To determine the test accuracy and cost-effectiveness of the SLN biopsy with (99m)Tc and/or blue dye compared with IFL or clinical follow-up for test negatives in vulval cancer, through systematic reviews and economic evaluation.

DATA SOURCES

Standard medical databases, including MEDLINE, EMBASE, Science Citation Index and The Cochrane Library, medical search gateways, reference lists of review articles and included studies were searched to January 2011.

METHODS

For accuracy and effectiveness, standard methods were used and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were to January 2011, with no language restrictions. Meta-analyses were carried out with Meta-Disc version 1.4 (Javier Zamora, Madrid, Spain) for accuracy; none was appropriate for effectiveness. The economic evaluation from a NHS perspective used a decision-tree model in DATA TreeAge Pro Healthcare 2001 (TreeAge Software, Inc., Williamstown, MA, USA). Six options (blue dye with H&E, blue dye with ultrastaging, (99m)Tc with H&E, (99m)Tc with ultrastaging, blue dye/(99m)Tc with H&E, blue dye/(99m)Tc with ultrastaging) were compared with IFL. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

For accuracy, of the 26 included studies, most evaluated (99m)Tc/blue dye combined. Four studies had clinical follow-up only for test negatives and five had clinical follow-up for all and IFL for test negatives. Numbers with no SLN found were difficult to distinguish from those with negative SLN biopsies. The largest group of 11 studies using (99m)Tc/blue dye, ultrastaging and immunohistochemistry had a pooled sensitivity of 95.6% [95% confidence interval (CI) 91.5% to 98.1%] and a specificity of 100% (95% CI 99.0% to 100%). Mean SLN detection rates were 94.6% for (99m)Tc, 68.7% for blue dye and 97.7% for both. One study measured global health status quality of life (QoL) and found no difference between SLN biopsy and IFL. One patient preference evaluation showed that 66% preferred IFL rather than a 5% false-negative rate from SLN biopsy. For effectiveness, of 14,038 references, one randomised controlled trial, three case-control studies and 13 case series were found. Approximately 50% died from vulval cancer and 50% from other causes during follow-ups. Recurrences were in the ratio of approximately 4 : 2 : 1 vulval, groin and distant, with more recurrences in node-positive patients. No studies reported QoL. For cost per death averted, IFL was less costly and more effective than strategies using SLN biopsy. For morbidity-free survival and long-term morbidity-free survival, (99m)Tc with ultrastaging was most cost-effective. Strategies with blue dye only and H&E only were never cost-effective. The incremental cost-effectiveness ratio for (99m)Tc with ultrastaging compared with IFL was £4300 per case of morbidity-free survival and £7100 per long-term morbidity-free survival.

LIMITATIONS

The main limitations of this study include the lack of good-quality evidence on accuracy, effectiveness and QoL. A large project such as this takes time to publish, so the most recent studies are not included.

CONCLUSIONS

A sensitive and specific combined metastatic SLN detection test and information on generic QoL in vulval cancer is urgently required.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.