Glycan-Tailored Glycoproteomic Analysis Reveals Serine is the Sole Residue Subjected to O-Linked Glycosylation in Acinetobacter baumannii.

Protein glycosylation is a ubiquitous process observed across all domains of life. Within the human pathogen Acinetobacter baumannii, O-linked glycosylation is required for virulence; however, the targets and conservation of glycosylation events remain poorly defined. In this work, we expand our understanding of the breadth and site specificity of glycosylation within A. baumannii by demonstrating the value of strain specific glycan electron-transfer/higher-energy collision dissociation (EThcD) triggering for bacterial glycoproteomics. By coupling tailored EThcD-triggering regimes to complementary glycopeptide enrichment approaches, we assessed the observable glycoproteome of three A. baumannii strains (ATCC19606, BAL062, and D1279779). Combining glycopeptide enrichment techniques including ion mobility (FAIMS), metal oxide affinity chromatography (titanium dioxide), and hydrophilic interaction liquid chromatography (ZIC-HILIC), as well as the use of multiple proteases (trypsin, GluC, pepsin, and thermolysis), we expand the known A. baumannii glycoproteome to 33 unique glycoproteins containing 42 glycosylation sites. We demonstrate that serine is the sole residue subjected to glycosylation with the substitution of serine for threonine abolishing glycosylation in model glycoproteins. An A. baumannii pan-genome built from 576 reference genomes identified that serine glycosylation sites are highly conserved. Combined this work expands our knowledge of the conservation and site specificity of A. baumannii O-linked glycosylation.

UK guidelines for the management of soft tissue sarcomas.

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Preoperative Radiotherapy in Patients With Primary Retroperitoneal Sarcoma: EORTC-62092 Trial (STRASS) Versus Off-trial (STREXIT) Results.

OBJECTIVE: The aim of the present study was to compare the effect of radiotherapy (RT) on abdominal recurrence-free survival (ARFS) in patients with primary retroperitoneal sarcoma treated in the EORTC-STBSG-62092 (STRASS) phase 3 randomized controlled trial (STRASS cohort) and off-trial (STREXIT cohort) and to pool STRASS and STREXIT data to test the hypothesis that RT improves ARFS in patients with liposarcoma. BACKGROUND: The STRASS trial did not show any difference in ARFS between patients treated with preoperative radiotherapy+surgery (RT+S) versus surgery alone (S). METHODS: All consecutive adult patients not enrolled in STRASS and underwent curative-intent surgery for a primary retroperitoneal sarcoma with or without preoperative RT between 2012 and 2017 (STRASS recruiting period) among ten STRASS-recruiting centres formed the STREXIT cohort. The effect of RT in STREXIT was explored with a propensity score (PS)-matching analysis. Primary endpoint was ARFS defined as macroscopically incomplete resection or abdominal recurrence or death of any cause, whichever occurred first. RESULTS: STRASS included 266 patients, STREXIT included 831 patients (727 after excluding patients who received preoperative chemotherapy, 202 after 1:1 PS-matching). The effect of RT on ARFS in STRASS and 1:1 PS-matched STREXIT cohorts, overall and in patients with liposarcoma, was similar. In the pooled cohort analysis, RT administration was associated with better ARFS in patients with liposarcoma [N=321, hazard ratio (HR), 0.61; 95% confidence interval (CI), 0.42-0.89]. In particular, patients with well-differentiated liposarcoma and G1-2 dedifferentiated liposarcoma (G1-2 DDLPS, n=266) treated with RT+S had better ARFS (HR, 0.63; 95% CI, 0.40-0.97) while patients with G3 DDLPS and leiomyosarcoma had not. At the current follow-up, there was no association between RT and overall survival or distant metastases-free survival. CONCLUSIONS: In this study, preoperative RT was associated with better ARFS in patients with primary well-differentiated liposarcoma and G1-2 DDLPS.

The Use of Indocyanine Green and Near-Infrared Fluorescence Imaging Versus Blue Dye in Sentinel Lymph Node Biopsy in Cutaneous Melanoma: A Retrospective, Cohort Study.

BACKGROUND: The use of indocyanine green (ICG) and near-infrared fluorescence imaging is a promising option for sentinel lymph node (SLN) mapping in cutaneous melanoma. The study objective was to compare the performance of ICG and blue dye at detecting SLNs with radioisotope nanocolloid (technetium-99). METHODS: Between April 2018 and June 2022, 293 consecutive patients with cutaneous melanoma (Breslow thickness ≥ 0.8 mm) underwent wide local excision and SLN biopsy. Patients were divided into group A (ICG; n = 122) and group B (blue dye; n = 163). All patients underwent SPECT/CT imaging preoperatively. SLN detection parameters and complications were compared between the groups. RESULTS: A total of 285 patients had complete data and were included in the analysis. The median age was 62.0 (range 10-91) years, and 139 (48.8%) were female patients. The mean Breslow thickness was 2.6 mm, 89 (31.2%) patients had ulceration, and 179 (62.8%) patients had mitosis ≥ 1 mm2. The mean number of SLNs detected per patient in group A was 1.58 and group B was 1.48. In groups A and B, the SLN detection rate was 96.7% versus 89.6% (p = 0.022) and the pathological SLN detection rate was 92.3% versus 97.1% (p = 0.481), respectively. CONCLUSIONS: ICG had a higher SLN detection rate and equal pathological SLN detection rate to blue dye. ICG may not be inferior to blue dye and is a useful adjunct to radioisotope in SLN biopsy in cutaneous melanoma.

Prognosis of Patients with Cutaneous Angiosarcoma After Surgical Resection with Curative Intent: Is There a Difference Between the Subtypes?

BACKGROUND: The etiology of cutaneous angiosarcoma (cAS) may be idiopathic (I-cAS), or arise secondary to radiotherapy (RT-cAS), in chronic lymphedema (ST-cAS), or related to UV exposure (UV-cAS). The aim of this study was to evaluate oncological outcomes of different cAS subtypes. PATIENTS AND METHODS: Non-metastatic cAS patients, treated with surgery for primary disease with curative intent, were retrospectively analyzed for oncological outcome, including local recurrence (LR), distant metastases (DM), and overall survival (OS). RESULTS: A total of 234 patients were identified; 60 I-cAS, 122 RT-cAS, 9 ST-cAS, and 43 UV-cAS. The majority was female (78%), the median age was 66 years (IQR 57-76 years), the median tumor size was 4.4 cm (IQR 2.5-7.0 cm), and most common site of disease was the breast (59%). Recurrence was identified in 66% (44% LR and/or 41% DM), with a median follow up of 26.5 months (IQR 12-60 months). The 5-year OS was estimated at 50%, LRFS at 47%, and DMFS at 50%. There was no significant difference in LR, DM, or OS between the subtypes. Age < 65 years and administration of radiotherapy (RT) were significantly associated with lower LR rates (HR 0.560, 95% CI 0.3373-0.840, p = 0.005 and HR 0.421, 95% CI 0.225-0.790, p = 0.007, respectively), however no prognostic factors were identified for development of DM. Development of DM, but not LR (p = 0.052), was significantly associated with decreased OS (HR 6.486, 95% CI 2.939-14.318 p < 0.001). CONCLUSION: We found no significant difference in oncological outcome between the different cAS subtypes. OS remains relatively poor, and RT is associated with lower LR rates.

Oncological Outcome After Lymph Node Dissection for Cutaneous Squamous Cell Carcinoma.

BACKGROUND: Although cutaneous squamous cell carcinoma (cSCC) is common, lymph node metastases are relatively rare and are usually treated with lymph node dissection (LND). The aim of this study was to describe the clinical course and prognosis after LND for cSCC at all anatomical locations. METHODS: A retrospective search at three centres was performed to identify patients with lymph node metastases of cSCC who were treated with LND. Prognostic factors were identified by uni- and multivariable analysis. RESULTS: A total of 268 patients were identified with a median age of 74. All lymph node metastases were treated with LND, and 65% of the patients received adjuvant radiotherapy. After LND, 35% developed recurrent disease both locoregionally and distantly. Patients with more than one positive lymph node had an increased risk for recurrent disease. 165 (62%) patients died during follow-up of whom 77 (29%) due to cSCC. The 5-year OS- and DSS rate were 36% and 52%, respectively. Disease-specific survival was significantly worse in immunosuppressed patients, patients with primary tumors >2cm and patients with more than one positive lymph node. CONCLUSIONS: This study shows that LND for patients with lymph node metastases of cSCC leads to a 5-year DSS of 52%. After LND, approximately one-third of the patients develop recurrent disease (locoregional and/or distant), which underscores the need for better systemic treatment options for locally advanced cSCC. The size of the primary tumor, more than one positive lymph node, and immunosuppression are independent predictors for risk of recurrence and disease-specific survival after LND for cSCC.

Assessment of inter-centre agreement across multidisciplinary team meetings for patients with retroperitoneal sarcoma.

BACKGROUND: Decision-making in the management of patients with retroperitoneal sarcoma is complex and requires input from a number of different specialists. The aim of this study was to evaluate the levels of agreement in terms of resectability, treatment allocation, and organs proposed to be resected across different retroperitoneal sarcoma multidisciplinary team meetings. METHODS: The CT scans and clinical information of 21 anonymized retroperitoneal sarcoma patients were sent to all of the retroperitoneal sarcoma multidisciplinary team meetings in Great Britain, which were asked to give an opinion about resectability, treatment allocation, and organs proposed to be resected. The main outcome was inter-centre reliability, which was quantified using overall agreement, as well as the chance-corrected Krippendorff's alpha statistic. Based on the latter, the level of agreement was classified as: 'slight' (0.00-0.20), 'fair' (0.21-0.40), 'moderate' (0.41-0.60), 'substantial' (0.61-0.80), or 'near-perfect' (>0.80). RESULTS: Twenty-one patients were reviewed at 12 retroperitoneal sarcoma multidisciplinary team meetings, giving a total of 252 assessments for analysis. Consistency between centres was only 'slight' to 'fair', with rates of overall agreement and Krippendorff's alpha statistics of 85.4 per cent (211 of 247) and 0.37 (95 per cent c.i. 0.11 to 0.57) for resectability; 80.4 per cent (201 of 250) and 0.39 (95 per cent c.i. 0.33 to 0.45) for treatment allocation; and 53.0 per cent (131 of 247) and 0.20 (95 per cent c.i. 0.17 to 0.23) for the organs proposed to be resected. Depending on the centre that they had attended, 12 of 21 patients could either have been deemed resectable or unresectable, and 10 of 21 could have received either potentially curative or palliative treatment. CONCLUSIONS: Inter-centre agreement between retroperitoneal sarcoma multidisciplinary team meetings was low. Multidisciplinary team meetings may not provide the same standard of care for patients with retroperitoneal sarcoma across Great Britain.

Long term culture promotes changes to growth, gene expression, and metabolism in CHO cells that are independent of production stability.

Phenotypic stability of Chinese hamster ovary (CHO) cells over long term culture (LTC) presents one of the most pressing challenges in the development of therapeutic protein manufacturing processess. However, our current understanding of the consequences of LTC on recombinant (r-) CHO cell lines is still limited, particularly as clonally-derived cell lines present distinct production stability phenotypes. This study evaluated changes of culture performance, global gene expression, and cell metabolism of two clonally-derived CHO cell lines with a stable or unstable phenotype during the LTC (early [EP] vs. late [LP] culture passages). Our findings indicated that LTC altered the behavior of CHO cells in culture, in terms of growth, overall gene expression, and cell metabolism. Regardless whether cells were categorized as stable or unstable in terms of r-protein production, CHO cells at LP presented an earlier decline in cell viability and loss of any observable stationary phase. These changes were parallelled by the upregulation of genes involved in cell proliferation and survival pathways (i.e., MAPK/ERK, PI3K-Akt). Stable and unstable CHO cell lines both showed increased consumption of glucose and amino acids at LP, with a parallel accumulation of greater amounts of lactate and TCA cycle intermediates. In terms of production stability, we found that decreased r-protein production in the unstable cell line directly correlated to the loss in r-gene copy number and r-mRNA expression. Our data revealed that LTC produced ubiquitious effects on CHO cell phenotypes, changes that were rooted in alterations in cell transcriptome and metabolome. Overall, we found that CHO cells adapted their cellular function to proliferation and survival during the LTC, some of these changes may well have limited effects on overall yield or specific productivity of the desired r-product, but they may be critical toward the capacity of cells to handle r-proteins with specific molecular features.

Questions of value, questions of magnitude: An exploration and application of methods for comparing indirect effects in multiple mediator models.

Mediation analysis is widely used to test and inform theory and debate about the mechanism(s) by which causal effects operate, quantitatively operationalized as an indirect effect in a mediation model. Most effects operate through multiple mechanisms simultaneously, and a mediation model is likely to be more realistic when it is specified to capture multiple mechanisms at the same time with the inclusion of more than one mediator in the model. This also allows an investigator to compare indirect effects to each other. After an overview of the mechanics of mediation analysis, we advocate formally comparing indirect effects in models that include more than one mediator, focusing on the important distinction between questions and claims about value (i.e., are two indirect effects the same number?) versus magnitude (i.e., are two indirect effects equidistant from zero or the same in strength?). After discussing the shortcomings of the conventional method for comparing two indirect effects in a multiple mediator model-which only answers a question about magnitude in some circumstances-we introduce several methods that, unlike the conventional approach, always answer questions about difference in magnitude. We illustrate the use of these methods and provide code that implements them in popular software. We end by summarizing simulation findings and recommending which method(s) to prefer when comparing like- and opposite-signed indirect effects.

Frailty in Very Elderly Patients is Not Associated with Adverse Surgical or Oncological Outcomes in Extremity Surgery for Soft Tissue Sarcoma.

BACKGROUND: While surgery remains the mainstay of treatment for limb sarcoma, extreme old age is a relative contraindication to oncological surgery. METHODS: Patients >80 years referred with primary extremity soft-tissue sarcoma (ESTS) between 2007 and 2016 were retrospectively reviewed. Prognostic variables, including ASA status and Clinical Frailty Scores, were collected. Endpoints were perioperative morbidity, locoregional (LRR) and distant recurrence (DR), disease-specific survival (DSS) adjusted using competing risk modelling, and overall survival (OS). RESULTS: A total of 141 primary tumours were identified, with 116 undergoing resections. Main motives for nonoperative management were severe frailty or significant comorbidity (56.0%). The operative group had a median age of 84 (range 80-96) years and median follow-up of 16 months (range 0-95). 45.7% of patients received radiotherapy. Median hospital stay was 7 (range 0-40) days, with frailty (p = 0.25) and ASA (p = 0.28) not associated with prolonged admission. 12.9% developed significant complications, with one perioperative mortality. 24.1% had LRR, occurring at a median of 14.5 months. All patients with reported DR (28.4%), except one, died of their disease. Frailty did not confer a significant difference in adjusted LRFS (p = 0.95) and DMFS (p = 0.84). One- and 5-year adjusted DSS and OS was 87.0% versus 74.9% and 62.3% versus 27.4%, respectively. Frailty (CFS ≥4) was associated with worse OS (hazard ratio [HR] 2.49; 95% confidence interval [CI] 1.51-4.12; p < 0.001), however not with adjusted DSS (p = 0.16). Nonoperative management conferred a 1- and 5-year adjusted DSS was 58.3% and 44.4%, respectively. CONCLUSIONS: Extremity surgery for sarcoma is well tolerated in the frail very elderly population with low morbidity and comparable oncological outcomes.

Association Between Ageing and Short-Term Survival Outcomes in Patients Undergoing Surgery for Primary Retroperitoneal Sarcoma.

BACKGROUND: As the population ages, more elderly patients are receiving surgery for retroperitoneal sarcoma (RPS). However, high-quality data investigating associations between ageing and prognosis are lacking. Our study aimed to investigate whether ageing is associated with inferior short-term survival outcomes after RPS surgery. PATIENTS AND METHODS: Patients undergoing surgery for primary RPS between 2008 and 2019 at two tertiary sarcoma centres were analysed. The primary outcome was 1-year mortality, and the primary explanatory variable was patient age, classified as: < 55, 55-64, 65-74 or 75+ years. RESULTS: The 692 patients undergoing surgery (mean age 60.8 ± 13.8 years) had a 1-year mortality rate of 9.4%, which differed significantly by age (p < 0.001), with rates of 7.2%, 6.9%, 8.7% and 22.8% for the < 55, 55-64, 65-74 and 75+ years groups, respectively. The distribution of causes of death also differed significantly by age (p = 0.023), with 22% and 28% of deaths in the 65-74 and 75+ years groups caused by post-operative complications, versus none in the < 55 and 55-64 years groups. On multivariable analysis, age of 75+ years (versus < 55 years) was a significant independent predictor of 1-year mortality [odds ratio (OR) 7.05, 95% confidence interval (CI) 2.63-18.9, p < 0.001]; no significant increase in risk was observed in the 55-64 (OR 0.72, 95% CI 0.28-1.87) or 65-74 (OR 0.89, 95% CI 0.37-2.15) years groups. CONCLUSIONS: Post-operative complications are an important cause of deaths in elderly patients. These findings are relevant to decision-making and counselling when surgery is considered for patients with RPS.

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.

Neoadjuvant Systemic Therapy (NAST) in Patients with Melanoma: Surgical Considerations by the International Neoadjuvant Melanoma Consortium (INMC).

Exciting advances in melanoma systemic therapies have presented the opportunity for surgical oncologists and their multidisciplinary colleagues to test the neoadjuvant systemic treatment approach in high-risk, resectable metastatic melanomas. Here we describe the state of the science of neoadjuvant systemic therapy (NAST) for melanoma, focusing on the surgical aspects and the key role of the surgical oncologist in this treatment paradigm. This paper summarizes the past decade of developments in melanoma treatment and the current evidence for NAST in stage III melanoma specifically. Issues of surgical relevance are discussed, including the risk of progression on NAST prior to surgery. Technical aspects, such as the definition of resectability for melanoma and the extent and scope of routine surgery are presented. Other important issues, such as the utility of radiographic response evaluation and method of pathologic response evaluation, are addressed. Surgical complications and perioperative management of NAST related adverse events are considered. The International Neoadjuvant Melanoma Consortium has the goal of harmonizing NAST trials in melanoma to facilitate rapid advances with new approaches, and facilitating the comparison of results across trials evaluating different treatment regimens. Our ultimate goals are to provide definitive proof of the safety and efficacy of NAST in melanoma, sufficient for NAST to become an acceptable standard of care, and to leverage this platform to allow more personalized, biomarker-driven, tailored approaches to subsequent treatment and surveillance.

Outcome after treatment for sebaceous carcinoma: A multicenter study.

BACKGROUND: Sebaceous carcinoma (SC) is a rare malignant tumour whereby, comprehensive long-term data are scarce. This study aimed to assess the outcome of patients treated with resection for SC. METHODS: Patients treated at four tertiary centres were included. Cumulative incidence curves were calculated for recurrences. RESULTS: A total of 100 patients (57 males, 57%) were included with 103 SCs. The median age was 72 (range, 15-95) years with a median follow-up of 52 (interquartile range [IQR], 24-93) months. Most SCs were located (peri)ocular (49.5%). Of all SCs, 17 locally recurred (16.5%) with a median time to recurrence of 19 (IQR, 8-29) months. The cumulative incidence probability for recurrence was statistically higher for (peri)ocular tumours (p = 0.005), and for positive resection margins (p = 0.001). Two patients presented with lymph node metastases and additional seven patients (8.7%) developed lymph node metastases during follow-up with a median time to metastases of 8 (IQR, 0.5-28) months. Three patients had concurrent in-transit metastases and one patient also developed liver and bone metastases during follow-up. CONCLUSION: SC is a rare, yet locally aggressive tumour. Positive resection margins and (peri)ocular SCs are more frequently associated with local recurrence. SC infrequently presents with locoregional or distant metastases.

Oncological Outcome After Diagnostic Biopsies in Gastrointestinal Stromal Tumors: A Retrospective Cohort Study.

OBJECTIVE: To analyze whether the route of preoperative biopsy influences oncological outcome in GIST patients. SUMMARY OF BACKGROUND DATA: Preoperative biopsies are widely used for diagnosing GIST. Little is known about the risk of tumor seeding after different routes of biopsy. METHODS: Patients who underwent resection of a primary GIST between 1996 and 2014 were identified from 2 databases from 2 tertiary referral centers. Survival data were obtained using the Kaplan-Meier method. Possible confounders were identified using Cox regression analysis. The primary endpoint was local recurrence free survival (RFS) and the secondary endpoint was DSS. RESULTS: A total of 228 patients were included, with a median age of 62 years (range 17-86) and a median follow-up time of 53 months (range 1-204). From these patients, 42 patients did not have a biopsy (18%), 70 underwent a transcutaneous biopsy (31%), and 116 a transluminal biopsy (51%). A total of 42 patients (19.0%) had a local and/or distant recurrence. From the 70 patients with a transcutaneous biopsy, only 1 patient developed a needle tract recurrence (1.4%). Local RFS and DSS were both significantly shorter in the transcutaneous biopsy group on univariate analysis compared to the other groups; however, in multivariate analysis the route of biopsy did not influence local RFS (P = 0.128) or DSS (P = 0.096). CONCLUSIONS: Transluminal or transcutaneous biopsies for diagnosing GIST do not significantly alter the risk of local recurrent disease or DSS in multivariate Cox regressions. The risk of needle tract seeding after transcutaneous biopsy was low.

Management of Primary Retroperitoneal Sarcoma (RPS) in the Adult: An Updated Consensus Approach from the Transatlantic Australasian RPS Working Group.

BACKGROUND: Retroperitoneal soft tissue sarcomas comprise a heterogeneous group of rare tumors of mesenchymal origin that include several well-defined histologic subtypes. In 2015, the Transatlantic Australasian RPS Working Group (TARPSWG) published consensus recommendations for the best management of primary retroperitoneal sarcoma (RPS). Since then, through international collaboration, new evidence and knowledge have been generated, creating the need for an updated consensus document. METHODS: The primary aim of this study was to critically evaluate the current evidence and develop an up-to-date consensus document on the approach to these difficult tumors. The resulting document applies to primary RPS that is non-visceral in origin, with exclusion criteria as previously described. The relevant literature was evaluated and an international group of experts consulted to formulate consensus statements regarding the best management of primary RPS. A level of evidence and grade of recommendation were attributed to each new/updated recommendation. RESULTS: Management of primary RPS was considered from diagnosis to follow-up. This rare and complex malignancy is best managed by an experienced multidisciplinary team in a specialized referral center. The best chance of cure is at the time of primary presentation, and an individualized management plan should be made based on the 29 consensus statements included in this article, which were agreed upon by all of the authors. Whenever possible, patients should be enrolled in prospective trials and studies. CONCLUSIONS: Ongoing international collaboration is critical to expand upon current knowledge and further improve outcomes of patients with RPS. In addition, prospective data collection and participation in multi-institution trials are strongly encouraged.

Overcoming bacteriophage insensitivity in Staphylococcus aureus using clindamycin and azithromycinat subinhibitory concentrations.

BACKGROUND: Staphylococcus aureus is a pathogen of major concern in both acute infections and chronic conditions such as chronic rhinosinusitis (CRS). Bacteriophage (phage) therapy has recently regained interest for its potential to treat infections caused by antibiotic resistant strains including Methicillin Resistant Staphylococcus aureus (MRSA). However, bacteria can adapt and become resistant to phages. The aim of this study is to determine the potential for antibiotics to overcome phage resistance. METHODS: The susceptibility of S. aureus clinical isolates (CIs) to phages J-Sa36, Sa83 and Sa87 alone or in combination with protein synthesis inhibitor (PSI) antibiotics clindamycin, azithromycin and erythromycin was assessed using plaque spot assays, minimum inhibitory concentration (MIC) assays, double layer spot assays and resazurin assays. The safety and efficacy of subinhibitory PSI antibiotics in combination with phage was tested in a Sprague Dawley rat model of sinusitis infected with a phage resistant S. aureus CI. RESULTS: All three antibiotics at subinhibitory concentrations showed synergy when combined with all 3 phages against S. aureus CIs in planktonic and biofilm form and could sensitize phage-resistant S. aureus to promote phage infection. The combination of topical subinhibitory clindamycin or azithromycin and phage was safe and could eradicate S. aureus sinonasal biofilms in vivo. CONCLUSION: Subinhibitory concentrations of PSI antibiotics could sensitize phage-resistant S. aureus and MRSA strains to phages in vitro and in vivo. This data supports the potential use of phage-PSI antibiotic combination therapies, in particular for difficult-to-treat infections with phage-resistant S. aureus and MRSA strains.

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.

A phase II study on the neo-adjuvant combination of pazopanib and radiotherapy in patients with high-risk, localized soft tissue sarcoma.

PURPOSE: A prior phase I study showed that the neo-adjuvant combination of pazopanib and radiotherapy was well tolerated, and induced promising pathological responses in soft-tissue sarcoma patients. Results of the subsequent prospective, multicenter phase II, PASART-2 trial are presented here, further investigating the efficacy and safety of this combination. PATIENTS AND METHODS: Patients with high-risk, localized soft-tissue sarcoma received neo-adjuvant radiotherapy, 50 Gy in 25 fractions (PASART-2A) or with a subsequent dose de-escalation to 36 Gy in 18 fractions (PASART-2B). This was combined with 800 mg once daily pazopanib, which started one week before radiotherapy and finished simultaneously. After an interval of 4-8 weeks, surgical resection was performed. The primary endpoint was the rate of pathological complete responses (pCR), defined as ≤5% viable cells. RESULTS: 25 patients were registered in the study, 21 in PASART-2A and 4 in PASART-2B. After central pathology review, the combination treatment led to a pCR in 5 patients (20%). 17 patients (68%) experienced grade 3+ toxicities during neo-adjuvant treatment, of which the most common were alanine aminotransferase (ALT) elevation, aspartate aminotransferase (AST) elevation, and hypertension, all asymptomatic. Grade 3+ acute post-operative toxicities occurred in 5 patients (20%), of which the most common was wound infection. All patients completed the full radiotherapy regimen and underwent surgery. Pazopanib was discontinued before completion in 9 patients (36%), due to elevated ALT and/or AST, and shortly interrupted in 2 patients (8%), due to hypertension. CONCLUSION: Apart from asymptomatic hepatotoxicity, the study regimen was well tolerated. Although the pre-specified efficacy endpoint (30% pCR) was not met, a more than doubling of historical pCR rates after neo-adjuvant radiotherapy alone was observed, which warrants further investigation.

Solitary fibrous tumor: molecular hallmarks and treatment for a rare sarcoma.

Solitary fibrous tumor (SFT) is a rare soft tissue sarcoma subtype which mainly affects adults in the fifth and sixth decades of life. Originally part of a spectrum of tumors called hemangiopericytomas, classification has been refined such that SFTs now represent a distinct subtype. The identification of NAB2-STAT6 fusion in virtually all SFTs has further aided to define this rare subgroup. SFTs have a spectrum of behavior from benign to malignant, with evidence suggesting risk of metastases related to age at diagnosis, extent of necrosis, mitotic rate and tumor size. The standard treatment for localized disease is surgical excision with or without radiotherapy. Retrospective and prospective evidence suggests antiangiogenic treatment is effective for unresectable disease. Further translational work is required to understand the biology driving the differential behavior and identify more effective treatments for patients with metastatic disease.