Gastrointestinal stromal tumour (GIST): British Sarcoma Group clinical practice guidelines.

BACKGROUND: British Sarcoma Group guidelines for the management of GIST were initially informed by those published by the European Society of Clinical Oncology. This update was written by a group of experts to includes a discussion of the highlight improvements in our knowledge of the disease and recent treatment developments. The guidelines include sections on Incidence, Aetiology, Diagnosis, including risk assessment, Treatment and Follow-up. METHODS: A careful review of the literature was performed to ensure that wherever possible recommendations are supported by the results of clinical trials or substantive retrospective reports. Areas of uncertainty are indicated appropriately. CONCLUSION: Guidelines represent a consensus view of current best clinical practice. Where appropriate, key recommendations are given and the levels of evidence and strength of recommendation gradings are those used by the European Society for Medical Oncology (ESMO).

Surveillance Post Surgery for Retroperitoneal Soft Tissue Sarcoma.

Complete en bloc surgical resection offers the best opportunity for the cure of primary retroperitoneal sarcomas (RPS). The potential for disease recurrence, in the form of both loco-regional recurrence and distant metastases, underpins the rationale for postoperative surveillance. There is a paucity of high-quality evidence underpinning follow-up for RPS patients, and most practice guidelines draw from expert opinion and evidence from soft tissue sarcomas of the extremities. The available observational retrospective data analysis has failed to demonstrate that high-intensity radiological surveillance improves the overall survival in patients. The lack of a robust evidence base has given rise to variations in approaches to post-operative surveillance strategies adopted by specialist centres managing RPS across the world. More high-quality prospective research is needed and planned to more clearly support surveillance approaches that balance oncologic outcomes, patient-centric care, and health service value. Risk stratification tools exist and are available for use in routine practice. Their use will likely support more individualised post-operative surveillance moving forward. Surveillance will likely be underpinned by serial radiological imaging for the medium term. However, developments in genomics offer hope for biomarkers such as ctDNA to impact patient care positively in the future and further support individualised patient care pathways.

Retrospective Analysis of Retroperitoneal-Abdominal-Pelvic Ganglioneuromas: An International Study by the Transatlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

OBJECTIVE: The Transatlantic Australasian Retroperitoneal Sarcoma Working Group conducted a retrospective study on the disease course and clinical management of ganglioneuromas. BACKGROUND: Ganglioneuromas are rare tumors derived from neural crest cells. Data on these tumors remain limited to case reports and single-institution case series. METHODS: Patients of all ages with pathologically confirmed primary retroperitoneal, intra-abdominal, and pelvic ganglioneuromas between January 1, 2000, and January 1, 2020, were included. We examined demographic, clinicopathologic, and radiologic characteristics, as well as clinical management. RESULTS: Overall, 328 patients from 29 institutions were included. The median age at diagnosis was 37 years with 59.1% of patients being female. Symptomatic presentation comprised 40.9% of cases, and tumors were often located in the extra-adrenal retroperitoneum (67.1%). At baseline, the median maximum tumor diameter was 7.2 cm. One hundred sixteen (35.4%) patients underwent active surveillance, whereas 212 (64.6%) patients underwent resection with 74.5% of operative cases achieving an R0/R1 resection. Serial tumor evaluations showed that malignant transformation to neuroblastoma was rare (0.9%, N=3). Tumors undergoing surveillance had a median follow-up of 1.9 years, with 92.2% of ganglioneuromas stable in size. With a median follow-up of 3.0 years for resected tumors, 84.4% of patients were disease free after resections, whereas recurrences were observed in 4 (1.9%) patients. CONCLUSIONS: Most ganglioneuromas have indolent disease courses and rarely transform to neuroblastoma. Thus, active surveillance may be appropriate for benign and asymptomatic tumors particularly when the risks of surgery outweigh the benefits. For symptomatic or growing tumors, resection may be curative.

Dealing with malignancy involving the inferior vena cava in the 21st century.

INTRODUCTION: Malignancies involving the inferior vena cava (IVC) have historically been considered not amendable to surgery. More recently, involvement of the IVC by neoplastic processes in the kidney, liver or in the retroperitoneum can be managed successfully. EVIDENCE ACQUISITION: In this systematic review we summarize the current evidence regarding the surgical management of the IVC in cases of involvement in neoplastic processes. Current literature was searched, and studies selected on the base of the PRISMA guidelines. Evidence was synthesized in narrative form due to heterogeneity of studies. EVIDENCE SYNTHESIS: Renal cell carcinoma accounts for the greatest proportion of studied patients and can be managed with partial or complete vascular exclusion of the IVC, thrombectomy and direct closure or patch repair with good oncological prognosis. Hepatic malignancies or metastases may involve the IVC, and the joint expertise of hepatobiliary and vascular surgeons has developed various strategies, according to the location of tumor and the need to perform a complete vascular exclusion above the hepatic veins. In retroperitoneal lymph node dissection, the IVC can be excised en-block to guarantee better oncological margins. Also, in retroperitoneal sarcomas not arising from the IVC a vascular substitution may be required to improve the overall survival by clearing all the neoplastic cells in the retroperitoneum. Leiomyoma can have a challenging presentation with involvement of the IVC requiring either thrombectomy, partial or complete substitution, with good oncological outcomes. CONCLUSIONS: A multidisciplinary approach with specialist expertise is required when dealing with IVC involvement in surgical oncology. Multiple techniques and strategies are required to deliver the most efficient care and achieve the best possible overall survival. The main aim of these procedures must be the complete clearance of all neoplastic cells and achievement of a safe margin according to the perioperative treatment strategy.

Emergency multivisceral resection for spontaneous haemorrhage rupture of huge solid pseudopapillary neoplasm of the pancreas during pregnancy†.

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare malignancy with a low malignant potential and strong female preponderance. Diagnosis during pregnancy is extraordinary, and management must consider the risks to the mother and foetus of tumour growth and rupture. A large 35-cm SPN was identified on magnetic resonance imaging (MRI) in a 24-year-old woman at 6 weeks of gestation following presentation with an abdominal mass. Surgery was delayed to allow the foetus to reach as close to term as possible because surveillance MRIs showed incremental mass growth. Emergency c-section was undertaken at 35 weeks of gestation due to persistent tachycardia and suspected haemorrhage into the tumour. A Hb of 70 g/l post-delivery despite four units of RBCs and an albumin of 11 g/l necessitated urgent multivisceral surgery. Surgical resection is the mainstay of treatment for SPN. However, the strategy of choice during pregnancy remains undetermined, with more recent reports delaying surgery until post-partum.

Evaluation of outcomes in the management of primary sporadic desmoid-type fibromatosis at a specialist soft tissue sarcoma unit.

BACKGROUND: Desmoids are rare fibroblastic tumours whose treatment in any individual case presents a persistent challenge. We endeavoured to evaluate various clinicopathological factors contributing to tumour behaviour. METHODS: This is a retrospective review of 95 primary truncal sporadic fibromatosis managed between 2011 and 2020. We studied progression rate for wait and watch (WW) and recurrence rate for the surgically treated group as adverse events. Relevant event-free survivals and potential risk factors were analysed over a median follow-up of 27 months. RESULTS: 66 patients (69.5%) received watchful surveillance and 28 upfront surgery. 2-year progression-free survival in WW group (88.9%) was higher than RFS in the surgical group (77.1%) p = 0.02. Adverse event rate compared favourably, 28.8% in WW and 28.6% in surgical group. At final follow-up, rate of stable disease for WW was 47%, and the regression rate was 24.2%. On Cox regression analysis, meantime to progress was 14 ± 2.0 months, with larger tumour size as a significant prognostic indicator (p = 0.05). Surgical group's mean time to recurrence was 13.8 ± 2.76 months, with tumour location a significant contributing factor (p = 0.05). CONCLUSIONS: This study confirms to the safety of both treatment approaches. Adverse event rates remained comparable, but event-free survival was longer for the watchful surveillance group.

Management of Locally Recurrent Retroperitoneal Sarcoma in the Adult: An Updated Consensus Approach from the Transatlantic Australasian Retroperitoneal Sarcoma Working Group.

BACKGROUND: Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS. METHODS: An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor. RESULTS: Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS. CONCLUSIONS: Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery.

Overall survival in abdominal wall sarcoma treated with curative intent surgery: A retrospective study from two European referral centres.

INTRODUCTION: Primary abdominal wall sarcomas are rare, heterogeneous tumours. The mainstay of management is surgery, although local recurrences (LR) and distant metastases (DM) are common. OBJECTIVES: Overall survival (OS) and disease-free survival (DFS) were primary outcomes; factors associated with prognosis secondary outcomes. MATERIALS AND METHODS: Patients undergoing surgery of primary abdominal wall sarcomas between April 2008 and May 2018 were identified at two referrals centres for sarcoma surgery. Patient demographics, tumour and treatment-related characteristics were recorded and analysed. RESULTS: A cohort of 65 patients underwent surgical resection with a median follow-up of 56 months, 5-year OS and DFS were 69% and 71%, respectively. Eleven patients (16.9%) experienced a recurrence event: 6 LR (9.2%), 10 DM (15.4%) and 5 both (7.7%). At univariate analysis, size (p = 0.03), grade (p = 0.001) and depth (p = 0.04) were associated with OS while size (p = 0.02) was associated with DFS. No significant relationship with tumour depth, type of surgery, surgical margin status or neo-/adjuvant treatment was demonstrated. CONCLUSION: Recurrence events are less common following treatment of abdominal wall sarcomas if compared to extremities STSs, but size (≥5 cm), high malignancy grade (FNCLCC 3) and depth are associated with worse OS.

Surgical management of a giant abdominal wall desmoid tumour.

Desmoid tumours are clonal fibroblastic proliferations in soft tissues, characterised by infiltrative growth and local recurrence, but not metastasis. Various treatment strategies for desmoid tumours exist, varying from observation, medical and systemic therapy to radiotherapy and surgery. A 25-year-old woman with a background of familial adenomatous polyposis was referred with an enlarging abdominal desmoid tumour measuring 40×40×40 cm despite repeated radiofrequency ablation, surgical debulking and hormone therapy. The patient had a two-stage operation. The first stage involved excision of the desmoid tumour with full-thickness abdominal wall. The abdominal wall was not closed, and a topical negative pressure seal was applied. After 2 days, she underwent the second stage: reconstruction of the abdominal wall defect with a large porcine mesh which was covered with anterolateral thigh flaps. Postoperative complications included ileus and a fall which required further surgery. The patient was discharged 1 month after the first operation. Abdominal MRI scans were performed at 3 and 7 months postdischarge and showed no recurrence of diseaseBackground.

Cheese and cheese infusions: ecological traps for mosquitoes and spotted wing Drosophila.

BACKGROUND: Harnessing insect ecology for insect control is an innovative concept that seeks to exploit, among others, insect-microbe ecological interactions for improved control of pest insects. Microbe-produced cheese odour attracts several dipterans, including host-seeking mosquitoes, but this phenomenon has not been thoroughly explored for mosquito control. Here we tested the hypothesis that attraction of mosquitoes to cheese odour can be exploited as an ecological trap for mosquito control. RESULTS: In laboratory and/or field experiments, we show that (i) each of five cheese varieties tested (Raclette, Pecorino, Brie, Gruyere, Limburger) strongly attracts female Aedes aegypti and Culex pipiens; (ii) cheese infusions, or headspace odourant extracts (HOEs) of cheese infusions, significantly affect oviposition choices by mosquitoes, (iii) HOEs contain at least 13 odourants; (iv) in field settings, cheese infusions more effectively stimulate mosquito oviposition than positive bluegrass infusion controls, and also capture (by drowning) the spotted wing Drosophila, Drosophila suzukii; and (v) home-made cheese infusions modulate oviposition choices by mosquito females and affect the survivorship of their offspring larvae. CONCLUSION: Our data show that microbial metabolites associated with cheese are attractive to mosquito females seeking hosts and oviposition sites and are likely toxic to mosquito larvae. These microbes and their metabolites could thus be co-opted for both the attract, and the kill, function of 'attract & kill' mosquito control tactics. Implementation of customizable and non-conventional nutritional media as microbe-based ecological traps presents a promising concept which exploits insect ecology for insect control. © 2021 Society of Chemical Industry.

Perioperative blood transfusion is not an independent predictor for worse outcomes in retroperitoneal sarcoma surgery.

BACKGROUND: Surgery for retroperitoneal soft tissue sarcoma (RPS) is technically challenging, often requiring perioperative red blood cell transfusion (PBT). In other cancers, controversy exists regarding the association of PBT and oncologic outcomes. No study has assessed this association in primary RPS, or identified factors associated with PBT. METHODS: Data was collected on all resected primary RPS between 2006 and 2020 at The Ottawa Hospital (Canada) and University Hospital Birmingham (United Kingdom). 'PBT' denotes transfusion given one week before surgery until discharge. Multivariable regression (MVA) identified clinicopathologic factors associated with PBT and assessed PBT association with oncologic outcomes. Surgical complexity was measured using resected organ score (ROS) and patterns of resection. RESULTS: 192 patients were included with 98 (50.8%) receiving PBT. Median follow-up was 38.2 months. High tumour grade (OR 2.20, P = 0.048), preoperative anemia (OR 2.78, P = 0.020), blood loss >1000 mL (OR 4.89, P = 0.004) and ROS >2 (OR 2.29, P = 0.026) were associated with PBT on MVA. A direct linear relationship was observed between higher ROS and increasing units of PBT (ß = 0.586, P = 0.038). Increasingly complex patterns of resection were associated with increasing odds of PBT. PBT was associated with severe post-operative complications (P = 0.008) on MVA. Univariable association between PBT and 5-year disease-free or overall survival was lost upon MVA. CONCLUSIONS: Surgical complexity and high tumour grade are potentially related to PBT. Oncologic outcomes are not predicted by PBT but are better explained by tumour grade which subsequently may increase surgical complexity. Strategies to reduce PBT should be considered in primary RPS patients.

Primary mesenteric sarcomas: Collaborative experience from the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG).

BACKGROUND: Primary mesenteric soft tissue sarcomas (STS) are rare and limited evidence is available to inform management. Surgical resection is challenging due to the proximity of vital structures and a need to preserve enteric function. OBJECTIVES: To determine the overall survival (OS) and recurrence-free survival (RFS) for patients undergoing primary resection for mesenteric STS. METHODS: The Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) is an intercontinental collaborative comprising specialist sarcoma centers. Data were collected retrospectively for all patients with mesenteric STS undergoing primary resection between 2000 and 2019. RESULTS: Fifty-six cases from 15 institutions were included. The spectrum of pathology was similar to the retroperitoneum, although of a higher grade. R0/R1 resection was achieved in 87%. Median OS was 56 months. OS was significantly shorter in higher-grade tumors (p = .018) and extensive resection (p < .001). No significant association between OS and resection margin or tumor size was detected. Rates of local recurrence (LR) and distant metastases (DM) at 5 years were 60% and 41%, respectively. Liver metastases were common (60%), reflecting portal drainage of the mesentery. CONCLUSION: Primary mesenteric sarcoma is rare, with a modest survival rate. LR and DM are frequent events. Liver metastases are common, highlighting the need for surveillance imaging.

Tumor necrosis is significantly associated with reduced recurrence-free survival after curative resection of gastrointestinal stromal tumors.

BACKGROUND OBJECTIVES: The impact of tumor necrosis as a prognostic factor in gastrointestinal stromal tumor (GISTs) is still debated. The objective was to determine whether tumor necrosis is an independent risk factor for survival in patients with GISTs. METHODS: Patients undergoing surgery for primary GIST from March 2003 to October 2018 at two sarcoma referral centers were retrospectively identified. Patients who received neoadjuvant imatinib were excluded. Multivariable Cox regression models were produced, to assess whether tumor necrosis was an independent predictor of either overall or recurrence-free survival. RESULTS: Forty-one out of 195 (21.0%) patients had tumor necrosis. Tumor necrosis was associated with a significantly higher modified National Institute of Health risk score, with 29 out of 41 (70.7%) patients with necrosis classified as high risk, compared to 52 out of 153 (34.0%) without (p < .001). Tumor necrosis was found to be independently predictive of recurrence-free survival (hazard ratio: 5.26, 95% CI: 2.62-10.56, p < .001) on multivariable analysis. At 5 years, 44.3% of patients with necrosis had either died or developed recurrence, compared to 9.9% of those without. CONCLUSION: Tumor necrosis is an independent predictor of recurrence-free survival in patients with operable GISTs. It should be routinely reported by pathologists, and used by clinicians when counseling patients and deciding on adjuvant therapy.

Outcome after ex situ or ante situm liver resection with hypothermic perfusion and auto-transplantation: A single-centre experience in adult and paediatric patients.

BACKGROUND: Evolving surgical technology and medical treatment have led to an expansion of indications to enable resection of large hepatic tumours with involvement of other abdominal structures. METHODS: Twelve extended liver and abdominal resections, either ex situ with auto-transplantation of the liver remnant or ante situm with veno-venous bypass (VVBP) were performed between 2016 and 2018. We describe our preoperative assessment, compare surgical strategies and assess outcomes. RESULTS: The median age of the 10 adult patients was 50.5 years with a majority suffering from sarcoma-like tumours. The two paediatric patients were 3 and 8 years of age, both with hepatoblastoma. Two patients underwent ex situ resections with auto-transplantation of the liver remnant, and nine patients had ante situm tumour removal with the use of VVBP in four. All patients achieved a good immediate liver function. Local infection and acute kidney injury were found in two patients. One patient underwent biliary reconstruction for bile leak. Tumour recurrence was seen in seven patients (58.3%), with four lung metastases. Five patients died from tumour recurrence (41.7%) during the follow-up. CONCLUSION: Extreme liver resections should be performed in experienced centres, where surgical subspecialties are available with access to cardiovascular support. Additionally, experience in split and living-donor liver transplantation is beneficial.

Surgery versus radical endotherapies for early cancer and high-grade dysplasia in Barrett's oesophagus.

BACKGROUND: Barrett's oesophagus is one of the most common pre-malignant lesions in the world. Currently the mainstay of therapy is surgical management of advanced cancer but this has improved the five-year survival very little since the 1980s. As a consequence, improved survival relies on early detection through endoscopic surveillance programmes. Success of this strategy relies on the fact that late-stage pre-malignant lesions or very early cancers can be cured by intervention. Currently there is considerable controversy over which method is best: that is conventional open surgery or endotherapy (techniques involving endoscopy). OBJECTIVES: We used data from randomised controlled trials (RCTs) to examine the effectiveness of endotherapies compared with surgery in people with Barrett's oesophagus, those with early neoplasias (defined as high-grade dysplasia (HGD) and those with early cancer (defined as carcinoma in-situ, superficially invasive, early cancer or superficial cancer T-1m (T1-a) and T-1sm (T1-b)). SEARCH METHODS: We used the Cochrane highly sensitive search strategy to identify RCTs in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, EBMR, Controlled Trials mRCT and ISRCTN, and LILACS, in July and August 2008. The searches were updated in 2009 and again in April 2012. SELECTION CRITERIA: Types of studies: RCTs comparing endotherapies with surgery in the treatment of high-grade dysplasia or early cancer. All cellular types of cancer were included (i.e. adenocarcinomas, squamous cell carcinomas and more unusual types) but will be discussed separately. TYPES OF PARTICIPANTS: patients of any age and either gender with a histologically confirmed diagnosis of early neoplasia (HGD and early cancer) in Barrett's or squamous lined oesophagus. Types of interventions; endotherapies (the intervention) compared with surgery (the control), all with curative intent. DATA COLLECTION AND ANALYSIS: Reports of studies that meet the inclusion criteria for this review would have been analysed using the methods detailed in Appendix 9. MAIN RESULTS: We did not identify any studies that met the inclusion criteria. In total we excluded 13 studies that were not RCTs but that compared surgery and endotherapies. AUTHORS' CONCLUSIONS: This Cochrane review has indicated that there are no RCTs to compare management options in this vital area, therefore trials should be undertaken as a matter of urgency. The problems with such randomised methods are standardising surgery and endotherapies in all sites, standardising histopathology in all centres, assessing which patients are fit or unfit for surgery and making sure there are relevant outcomes for the study (i.e. long-term survival (over five or more years)) and no progression of HGD.

A review of retroperitoneal liposarcoma genomics.

Retroperitoneal liposarcomas are rare tumours that carry a poorer prognosis than their extremity counterparts. Within their subtypes - well differentiated (WDL), dedifferentiated (DDL), myxoid (MLS) and pleomorphic (PLS) - they exhibit a diverse genomic landscape. With recent advances in next generation sequencing, the number of studies exploring this have greatly increased. The recent literature has deepened our understanding of the hallmark MDM2/CDK4 amplification in WDL/DDL and addressed concerns about toxicity and resistance when targeting this. The FUS-DDIT3 fusion gene remains the primary focus of interest in MLS with additional potential targets described. Whole genome sequencing has driven identification of novel genes and pathways implicated in WDL/DDL outside of the classic 12q13-15 amplicon. Due to their rarity; anatomical location and histologic subtype are infrequently mentioned when reporting the results of these studies. Reports can include non-adipogenic or extremity tumours, making it difficult to draw specific retroperitoneal conclusions. This narrative review aims to provide a summary of retroperitoneal liposarcoma genomics and the implications for therapeutic targeting.

Modeled distributions of Aedes japonicus japonicus and Aedes togoi (Diptera: Culicidae) in the United States, Canada, and northern Latin America.

The Asian bush mosquito, Aedes japonicus japonicus, and the coastal rock pool mosquito, Aedes togoi, are potential disease vectors present in both East Asia and North America. While their ranges are fairly well-documented in Asia, this is not the case for North America. We used maximum entropy modeling to estimate the potential distributions of Ae. togoi and Ae. j. japonicus in the United States, Canada, and northern Latin America under contemporary and future climatic conditions. Our results suggest suitable habitat that is not known to be occupied for Ae. j. japonicus in Atlantic and western Canada, Alaska, the western, midwestern, southern, and northeastern United States, and Latin America, and for Ae. togoi along the Pacific coast of North America and the Hawaiian Islands. Such areas are at risk of future invasion or may already contain undetected populations of these species. Our findings further predict that the limits of suitable habitat for each species will expand northward under future climatic conditions.

Lemongrass and Cinnamon Bark: Plant Essential Oil Blend as a Spatial Repellent for Mosquitoes in a Field Setting.

Plant essential oils (EOs) have been considered as spatial repellents to help disrupt the pathogen transmission cycle of mosquitoes. Our objective was to assess spatial repellency effects of EOs on the tropical yellow fever mosquito, Aedes aegypti (L.) (Diptera: Culicidae) and on local mosquito populations in coastal British Columbia (Canada). In laboratory experiments using protocols of the World Health Organization, three of the solitary EOs tested proved repellent to Ae. aegypti: cinnamon bark, lemongrass, and rosemary. Binary combinations of select EOs enhanced the repellent effect of single EOs through synergistic interactions. The EO blend of geranium and peppermint lowered the RD50 (the dose required to obtain 50% repellency) of each solitary EO by >1,000-fold. Compared with binary EO blends, ternary EO blends were typically less repellent to mosquitoes, possibly due to a dilution effect of the most effective EO constituent(s) in the blend. In field experiments, the EO blend of lemongrass and cinnamon bark expressed spatial repellency towards the cool weather mosquito, Culiseta incidens (Thomson) (Diptera: Culicidae), even when this blend was disseminated from devices as much as 1 m away from a sentinel trap releasing attractive vertebrate host odorants and CO2. Deployment of EOs as spatial repellents in small outdoor gatherings could help protect humans from mosquito-borne diseases, particularly when this tactic is coupled with other tools of mosquito management.

Surgical Trainee Feedback-Seeking Behavior in the Context of Workplace-Based Assessment in Clinical Settings.

PURPOSE: To investigate surgical trainee feedback-seeking behaviors-directly asking for feedback (inquiry) and observing and responding to situational clues (monitoring)-in the context of workplace-based assessment (WBA). METHOD: A hypothetical model of trainee feedback-seeking behavior was developed using existing literature. A questionnaire, incorporating previously validated instruments from organizational psychology, was distributed to general surgical trainees at 23 U.K. hospitals in 2012-2013. Statistical modeling techniques compared the data with 12 predetermined hypothetical relationships between feedback-seeking behaviors and predictive variables (goal orientation, supervisory style) through mediating variables (perceptions of personal benefits and costs of feedback) to develop a final model. RESULTS: Of 235 trainees invited, 178 (76%) responded. Trainees completed 48 WBAs/year on average, and 73% reported receiving feedback via WBA. The final model was of good fit (chi-square/degree of freedom ratio = 1.620, comparative fit index = 0.953, root mean square error of approximation = 0.059). Modeled data showed trainees who perceive personal benefits to feedback use both feedback inquiry and monitoring to engage in feedback interactions. Trainees who seek feedback engage in using WBA. Trainees' goal orientations and perceptions of trainers' supervisory styles as supportive and instrumental are associated with perceived benefits and costs to feedback. CONCLUSIONS: Trainees actively engage in seeking feedback and using WBA. Their perceptions of feedback benefits and costs and supervisory style play a role in their feedback-seeking behavior. Encouraging trainees to actively seek feedback by providing specific training and creating a supportive environment for feedback interactions could positively affect their ability to seek feedback.