Structural Basis of Peptide-Based Antimicrobial Inhibition of a Resistance-Nodulation-Cell Division Multidrug Efflux Pump.

Bacterial efflux pumps in the resistance-nodulation-cell division (RND) family of Gram-negative bacteria contribute significantly to the development of antimicrobial resistance by many pathogens. In this study, we selected the MtrD transporter protein of Neisseria gonorrhoeae as it is the sole RND pump possessed by this strictly human pathogen and can export multiple antimicrobials, including antibiotics, bile salts, detergents, dyes, and antimicrobial peptides. Using knowledge from our previously published structures of MtrD in the presence or absence of bound antibiotics as a model and the known ability of MtrCDE to export cationic antimicrobial peptides, we hypothesized that cationic peptides could be accommodated within MtrD binding sites. Furthermore, we thought that MtrD-bound peptides lacking antibacterial action could sensitize bacteria to an antibiotic normally exported by the MtrCDE efflux pump or other similar RND-type pumps possessed by different Gram-negative bacteria. We now report the identification of a novel nonantimicrobial cyclic cationic antimicrobial peptide, which we termed CASP (cationic antibiotic-sensitizing peptide). By single-particle cryo-electron microscopy, we found that CASP binds within the periplasmic cleft region of MtrD using overlapping and distinct amino acid contact sites that interact with another cyclic peptide (colistin) or a linear human cationic antimicrobial peptide derived from human LL-37. While CASP could not sensitize Neisseria gonorrhoeae to an antibiotic (novobiocin) that is a substrate for RND pumps, it could do so against multiple Gram-negative, rod-shaped bacteria. We propose that CASP (or future derivatives) could serve as an adjuvant for the antibiotic treatment of certain Gram-negative infections previously thwarted by RND transporters. IMPORTANCE RND efflux pumps can export numerous antimicrobials that enter Gram-negative bacteria, and their action can reduce the efficacy of antibiotics and provide decreased susceptibility to various host antimicrobials. Here, we identified a cationic antibiotic-sensitizing peptide (CASP) that binds within the periplasmic cleft of an RND transporter protein (MtrD) produced by Neisseria gonorrhoeae. Surprisingly, CASP was able to render rod-shaped Gram-negative bacteria, but not gonococci, susceptible to an antibiotic that is a substrate for the gonococcal MtrCDE efflux pump. CASP (or its future derivatives) could be used as an adjuvant to treat infections for which RND efflux contributes to multidrug resistance.

Surgical, Radiation, and Systemic Treatments of Patients With Thymic Epithelial Tumors: A Clinical Practice Guideline.

INTRODUCTION: The aim of this guideline was to provide recommendations for the most effective therapy for patients with thymic epithelial tumors, including thymoma, thymic carcinoma, and thymic neuroendocrine tumors (NETs). This guideline is intended to be used by all health care professionals managing patients with thymic epithelial tumors. METHODS: The guideline was developed by Ontario Health (Cancer Care Ontario)'s Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of the evidence, expert consensus, and formal internal and external reviews. RESULTS: Evidence-based recommendations were developed to improve the management of patients with thymic epithelial tumors. The guideline includes recommendations for surgical, radiation, and systemic treatments for patients with thymoma, thymic carcinoma, and thymic NETs separated by stage of disease using the TNM staging system. Recommendations for patients with thymic NETs were endorsed from the 2021 National Comprehensive Cancer Network Neuroendocrine and Adrenal Tumors Guideline. CONCLUSIONS: This guideline reflects the new staging system for patients with thymoma and thymic carcinoma and includes supporting evidence from the best available studies.

Circulating tumor cells detected in follow-up predict survival outcomes in tri-modality management of advanced non-metastatic esophageal cancer: a secondary analysis of the QUINTETT randomized trial.

BACKGROUND: Our aim was to establish if presence of circulating tumor cells (CTCs) predicted worse outcome in patients with non-metastatic esophageal cancer undergoing tri-modality therapy. METHODS: We prospectively collected CTC data from patients with operable non-metastatic esophageal cancer from April 2009 to November 2016 enrolled in our QUINTETT esophageal cancer randomized trial (NCT00907543). Patients were randomized to receive either neoadjuvant cisplatin and 5-fluorouracil (5-FU) plus radiotherapy followed by surgical resection (Neoadjuvant) or adjuvant cisplatin, 5-FU, and epirubicin chemotherapy with concurrent extended volume radiotherapy following surgical resection (Adjuvant). CTCs were identified with the CellSearch® system before the initiation of any treatment (surgery or chemoradiotherapy) as well as at 6-, 12-, and 24-months post-treatment. The threshold for CTC positivity was one and the findings were correlated with patient prognosis. RESULTS: CTC data were available for 74 of 96 patients and identified in 27 patients (36.5%) at a median follow-up of 13.1months (interquartile range:6.8-24.1 months). Detection of CTCs at any follow-up visit was significantly predictive of worse disease-free survival (DFS;hazard ratio [HR]: 2.44; 95% confidence interval [CI]: 1.41-4.24; p=0.002), regional control (HR: 6.18; 95% CI: 1.18-32.35; p=0.031), distant control (HR: 2.93; 95% CI: 1.52-5.65;p=0.001) and overall survival (OS;HR: 2.02; 95% CI: 1.16-3.51; p=0.013). After adjusting for receiving neoadjuvant vs. adjuvant chemoradiotherapy, the presence of CTCs at any follow-up visit remained significantly predictive of worse OS ([HR]:2.02;95% [Cl]:1.16-3.51; p=0.013) and DFS (HR: 2.49;95% Cl: 1.43-4.33; p=0.001). Similarly, any observed increase in CTCs was significantly predictive of worse OS (HR: 3.14; 95% CI: 1.56-6.34; p=0.001) and DFS (HR: 3.34; 95% CI: 1.67-6.69; p<0.001). CONCLUSION: The presence of CTCs in patients during follow-up after tri-modality therapy was associated with significantly poorer DFS and OS regardless of timing of chemoradiotherapy.

The quality of life in neoadjuvant versus adjuvant therapy of esophageal cancer treatment trial (QUINTETT): Randomized parallel clinical superiority trial.

BACKGROUND: We compared the health-related quality of life (HRQOL) in patients undergoing trimodality therapy for resectable stage I-III esophageal cancer. METHODS: A total of 96 patients were randomized to standard neoadjuvant cisplatin and 5-fluorouracil chemotherapy plus radiotherapy (neoadjuvant) followed by surgical resection or adjuvant cisplatin, 5-fluorouracil, and epirubicin chemotherapy with concurrent extended volume radiotherapy (adjuvant) following surgical resection. RESULTS: There was no significant difference in the functional assessment of cancer therapy-esophageal (FACT-E) total scores between arms at 1 year (p = 0.759) with 36% versus 41% (neoadjuvant vs. adjuvant), respectively, showing an increase of ≥15 points compared to pre-treatment (p = 0.638). The HRQOL was significantly inferior at 2 months in the neoadjuvant arm for FACT-E, European Organization for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-OG25), and EuroQol 5-D-3 L in the dysphagia, reflux, pain, taste, and coughing domains (p < 0.05). Half of patients were able to complete the prescribed neoadjuvant arm chemotherapy without modification compared to only 14% in the adjuvant arm (p < 0.001). Chemotherapy related adverse events of grade ≥2 occurred significantly more frequently in the neoadjuvant arm (100% vs. 69%, p < 0.001). Surgery related adverse events of grade ≥2 were similar in both arms (72% vs. 86%, p = 0.107). There were no 30-day mortalities and 2% vs. 10% 90-day mortalities (p = 0.204). There were no significant differences in either overall survival (OS) (5-year: 35% vs. 32%, p = 0.409) or disease-free survival (DFS) (5-year: 31% vs. 30%, p = 0.710). CONCLUSION: Trimodality therapy is challenging for patients with resectable esophageal cancer regardless of whether it is given before or after surgery. Newer and less toxic protocols are needed.

Plasma Metabolites Associated with Coffee Consumption: A Metabolomic Approach within the PREDIMED Study.

Few studies have examined the association of a wide range of metabolites with total and subtypes of coffee consumption. The aim of this study was to investigate associations of plasma metabolites with total, caffeinated, and decaffeinated coffee consumption. We also assessed the ability of metabolites to discriminate between coffee consumption categories. This is a cross-sectional analysis of 1664 participants from the PREDIMED study. Metabolites were semiquantitatively profiled using a multiplatform approach. Consumption of total coffee, caffeinated coffee and decaffeinated coffee was assessed by using a validated food frequency questionnaire. We assessed associations between 387 metabolite levels with total, caffeinated, or decaffeinated coffee consumption (≥50 mL coffee/day) using elastic net regression analysis. Ten-fold cross-validation analyses were used to estimate the discriminative accuracy of metabolites for total and subtypes of coffee. We identified different sets of metabolites associated with total coffee, caffeinated and decaffeinated coffee consumption. These metabolites consisted of lipid species (e.g., sphingomyelin, phosphatidylethanolamine, and phosphatidylcholine) or were derived from glycolysis (alpha-glycerophosphate) and polyphenol metabolism (hippurate). Other metabolites included caffeine, 5-acetylamino-6-amino-3-methyluracil, cotinine, kynurenic acid, glycocholate, lactate, and allantoin. The area under the curve (AUC) was 0.60 (95% CI 0.56-0.64), 0.78 (95% CI 0.75-0.81) and 0.52 (95% CI 0.49-0.55), in the multimetabolite model, for total, caffeinated, and decaffeinated coffee consumption, respectively. Our comprehensive metabolic analysis did not result in a new, reliable potential set of metabolites for coffee consumption.

A case-control, mono-center, open-label, pilot study to evaluate the feasibility of therapeutic touch in preventing radiation dermatitis in women with breast cancer receiving adjuvant radiation therapy.

BACKGROUND: Therapeutic touch (TT) is a non-invasive commonly used complementary therapy. TT is based on the use of hand movements and detection of energy field congestion to correct imbalances. Improvement in subjective symptoms in a variety of clinical trials has been seen with TT. The effect of TT during radiotherapy for breast cancer is unknown. METHODS: Women undergoing adjuvant radiation for Stage I/II breast cancer post conservative surgery were recruited for this cohort study. TT treatments were administered three times per week following radiation therapy. Feasibility was defined as an a priori threshold of 15 of 17 patients completing all TT treatments. The preventive effectiveness of TT was evaluated by documenting the 'time to develop' and the 'worst grade of radiation' dermatitis. Toxicity was assessed using NCIC CTC V3 dermatitis scale. Cosmetic rating was performed using the EORTC Breast Cosmetic Rating. The quality of life, mood and energy, and fatigue were assessed by EORTC QLQ C30, POMS, and BFI, respectively. The parameters were assessed at baseline, and serially during treatment. RESULTS: A total of 49 patients entered the study (17 in the TT Cohort and 32 in the Control Cohort). Median age in TT arm was 63 years and in control arm was 59 years. TT was considered feasible as all 17 patients screened completed TT treatment. There were no side effects observed with the TT treatments. In the TT Cohort, the worst grade of radiation dermatitis was grade II in nine patients (53%). Median time to develop the worst grade was 22 days. In the Control Cohort, the worst grade of radiation dermatitis was grade III in 1 patient. However, the most common toxicity grade was II in 15 patients (47%). Three patients did not develop any dermatitis. Median time to develop the worst grade in the control group was 31 days. There was no difference between cohorts for the overall EORTC cosmetic score and there was no significant difference in before and after study levels in quality of life, mood and fatigue. CONCLUSION: This study is the first evaluation of TT in patients with breast cancer using objective measures. Although TT is feasible for the management of radiation induced dermatitis, we were not able to detect a significant benefit of TT on NCIC toxicity grade or time to develop the worst grade for radiation dermatitis. In addition, TT did not improve quality of life, mood, fatigue and overall cosmetic outcome.

Adjuvant concurrent chemoradiation using intensity-modulated radiotherapy and simultaneous integrated boost for resected high-risk adenocarcinoma of the distal esophagus and gastro-esophageal junction.

PURPOSE: Multimodality therapy leads to improved outcomes for adenocarcinoma of the distal esophagus and gastroesophageal junction (GEJ) over surgery alone. At our institution, adjuvant chemoradiation (chemoRT) using IMRT and SIB is standard of care for resected high-risk disease. In this study, we review our experience with a recent cohort of patients treated in this manner. METHODS AND MATERIALS: We identified 18 patients with resected T3 and/or N1 adenocarcinoma of the distal esophagus and GEJ who received adjuvant chemoRT. A large elective volume (PTV1) and a smaller high-risk volume (PTV2) were irradiated simultaneously using IMRT and an SIB technique. All patients received concurrent chemotherapy. Relevant clinical outcomes are reported. RESULTS: The median dose to 95% of PTV1 was 3747cGy and to 95% of PTV2 was 4876cGy. All RT was given in a median of 28 daily fractions. Four patients did not complete chemotherapy. At a median follow up of 952 days from the start of RT, 7 of 18 patients were dead; of these, 3 had developed local recurrence only; 3 had developed both local and distant recurrence; 1 died of a late toxicity, without recurrence. OS was 88% at 1year, 76% at 2 years and 58% at 3 years. Freedom from local recurrence was 88% at 1 year, 82% at 2 years and 82% at 3 years. Freedom from distant recurrence was 72% at 1 year, 67% at 2 years and 56% at 3 years. Toxicity was acceptable. CONCLUSIONS: Adjuvant concurrent chemoRT with IMRT and SIB is feasible for resected high-risk adenocarcinoma of the distal esophagus and GEJ. Our results describe how modern treatment techniques can be employed as part of a treatment paradigm that is neither commonly used nor commonly described in the literature.

Outcome analysis of breast cancer patients who declined evidence-based treatment.

BACKGROUND: To analyze the characteristics and outcomes of women with breast cancer in the Northern Alberta Health Region (NAHR) who declined recommended primary standard treatments. METHODS: A chart review was performed of breast cancer patients who refused recommended treatments during the period 1980 to 2006. A matched pair analysis was performed to compare the survival data between those who refused or received standard treatments. RESULTS: A total of 185 (1.2%) patients refused standard treatment. Eighty-seven (47%) were below the age of 75 at diagnosis. The majority of those who refused standard treatments were married (50.6%), 50 years or older (60.9%), and from the urban area (65.5%). The 5-year overall survival rates were 43.2% (95% CI: 32.0 to 54.4%) for those who refused standard treatments and 81.9% (95% CI: 76.9 to 86.9%) for those who received them. The corresponding values for the disease-specific survival were 46.2% (95% CI: 34.9 to 57.6%) vs. 84.7% (95% CI: 80.0 to 89.4%). CONCLUSIONS: Women who declined primary standard treatment had significantly worse survival than those who received standard treatments. There is no evidence to support using Complementary and Alternative Medicine (CAM) as primary cancer treatment.