Comparing Multivisceral Resection with Tumor-only Resection of Liposarcoma Using the Win Ratio

BACKGROUND

Multivisceral resection of retroperitoneal liposarcoma (LPS) is associated with increased morbidity and may not confer a survival benefit compared with tumor-only (TO) resection. We compared both approaches using a novel statistical method called the "win ratio" (WR).

METHODS

Patients who underwent resection of LPS from 2004 to 2015 were identified from the National Cancer Database. Multivisceral resection was defined as removal of the primary site in addition to other organs. The WR was calculated based on a hierarchy of postoperative outcomes: 30-day and 90-day mortality, long-term survival, and severe complication.

RESULTS

Among 958 patients (multivisceral 634, TO 324) who underwent resection, the median age was 63 years (interquartile range [IQR] 54-71) with a median follow-up of 51 months (IQR 30-86). There was no difference in the WR among patients who underwent TO versus multivisceral resection in the matched cohort (WR 0.82, 95% confidence interval [CI] 0.61-1.10). In patients aged 72-90 years, those who underwent multivisceral resection had 36% lower odds of winning compared with patients undergoing TO resection (WR 0.64, 95% CI 0.40-0.98). A subgroup analysis of patients classified as not having adjacent tumor involvement at the time of surgery revealed that those patients who underwent multivisceral resection had 33% lower odds of winning compared to TO resection (WR 0.67, 95% CI 0.45-0.99).

CONCLUSIONS

Based on win-ratio assessments of a hierarchical composite endpoint, multivisceral resection in patients without adjacent tumor involvement may not confer improved outcomes. This method supports the rationale for less invasive resection of LPS in select patients, especially older patients.

Radiation therapy for retroperitoneal sarcoma: practice patterns in North America

BACKGROUND

The addition of radiation therapy (RT) to surgery in retroperitoneal sarcoma (RPS) remains controversial. We examined practice patterns in the use of RT for patients with RPS over time in a large, national cohort.

METHODS

Patients in the National Cancer Database (2004-2017) who underwent resection of RPS were included. Trends over time for proportions were calculated using contingency tables with Cochran-Armitage Trend test.

RESULTS

Of 7,485 patients who underwent resection, 1,821 (24.3%) received RT (adjuvant: 59.9%, neoadjuvant: 40.1%). The use of RT decreased annually by < 1% (p = 0.0178). There was an average annual increase of neoadjuvant RT by 13% compared to an average annual decrease of adjuvant RT by 6% (p < 0.0001). Treatment at high-volume centers (OR 14.795, p < 0.0001) and tumor > 10 cm (OR 2.009, p = 0.001) were associated with neoadjuvant RT. In contrast liposarcomas (OR 0.574, p = 0.001) were associated with adjuvant RT. There was no statistically significant difference in overall survival between patients treated with surgery alone versus surgery and RT (p = 0.07).

CONCLUSION

In the United States, the use of RT for RPS has decreased over time, with a shift towards neoadjuvant RT. However, a large percentage of patients are still receiving adjuvant RT and this mostly occurs at low-volume hospitals.

Enhancer Coamplification and Hijacking Promote Oncogene Expression in Liposarcoma

SIGNIFICANCE

Comprehensive profiling of the enhancer landscape and 3D genome structure in liposarcoma identifies extensive enhancer-oncogene coamplification and enhancer hijacking events, deepening the understanding of how oncogenes are regulated in cancer.

Emerging Trends in Immunotherapy for Adult Sarcomas

Soft-tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that arise from the oncogenic transformation of mesenchymal tissue. There are over 100 distinct STS histological and molecular subtypes with unique clinical, therapeutic, and prognostic features with variable responses to therapy regimens. Given the quality-of-life concerns and limited efficacy with current regimens, including cytotoxic chemotherapy, there is a need for novel therapies and regimens to treat advanced STS. Although immune checkpoint inhibitors have demonstrated significant improvements in survival outcomes in other cancer types, there remains ambiguous data on the impact of immunotherapy in sarcoma. Biomarkers like PD-1/PD-L1 are not always predictive of outcomes. Therefore, researching emerging novel therapies, such as CAR-T and adoptive cell therapies, is critical to understanding STS biology, STS tumor immune microenvironment immunomodulatory strategies that improve immune response, and survival outcomes. We discuss the underlying biology of the STS tumor immune microenvironment, immunomodulatory strategies that augment pre-existing immune responses, and novel approaches to develop sarcoma-specific antigen-based therapies.

POS1045 MASS SPECTROMETRY-BASED PROTEOMICS FOR THE IDENTIFICATION OF CANDIDATE SERUM PROTEIN BIOMARKERS THAT MAY PREDICT TREATMENT RESPONSE IN PATIENTS WITH PSORIATIC ARTHRITIS

Background

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) has identified a need for biomarkers to predict which patients (pts) with psoriatic arthritis (PsA) are most likely to respond to a specific therapy. Failure to identify effective treatments early on results in sub-optimal PsA disease management. Tofacitinib is an oral JAK inhibitor for the treatment of PsA. The efficacy and safety of tofacitinib 5 and 10 mg twice daily (BID) in pts with PsA have been demonstrated.1,2

Objectives

To identify protein biomarker candidates, which may identify responders (R) vs non-responders (NR) to treatment of PsA, using mass spectrometry-based proteomics.

Methods

Baseline (BL) serum samples from pts with PsA receiving tofacitinib 5 or 10 mg BID, adalimumab or placebo in OPAL Broaden (NCT01877668)1 were analysed. Pts were identified as R and NR based on the Psoriatic Arthritis Disease Activity Score (PASDAS) at Month 3; pts with lowest PASDAS ≤3.2 were defined as R, those with highest PASDAS >3.2 as NR. Two proteomic strategies were employed for analysis of BL serum samples: (1) targeted mass spectrometric multiple reaction monitoring analysis of an in-house panel (‘PAPRICA’) comprising of 206 proteins, originally developed to distinguish between different arthropathies, and (2) unbiased discovery liquid chromatography-tandem mass spectrometry (LC-MS/MS). PAPRICA data were normalised using two methods: normalisation to stable isotopically labelled peptide spike-ins (SIL; corrects for fluctuations in sample injections/mass spectrometry loading amounts), and normalisation to an endogenous peptide panel representing total serum protein abundance (TSPA; corrects for different amounts of total serum protein across samples). Univariate analyses (Student’s t-test) and multivariate machine learning Random Forest (RF) modelling3 were performed. Univariate analysis of the PAPRICA panel of proteins was performed on R vs NR, and within each treatment arm, with no adjustment for multiplicity.

Results

96 pts were identified as 47 R and 49 NR based on PASDAS scores. Of pts receiving tofacitinib 5 or 10 mg BID (data pooled), adalimumab or placebo, there were 26 R vs 26 NR, 13 R vs 13 NR and 8 R vs 10 NR, respectively. Results from univariate analysis identified 110 differentially expressed PAPRICA peptides between R vs NR (p≤0.05). RF multivariate analysis of all data (n=96) revealed a set of PAPRICA peptide signatures with the ability to differentiate between R and NR. Two RF models generated from the PAPRICA peptide data had training area under curves (AUCs) 0.956 [95% CI 0.93, 0.99] (TSPA) and 0.959 [95% CI 0.94, 0.98] (SIL). In total, 115 PAPRICA peptides representing 87 proteins were identified as potential biomarkers for predicting treatment response. Using unbiased discovery LC-MS/MS, univariate analysis of all data revealed one candidate peptide biomarker (p≤0.05). RF modelling revealed peptides that contributed to two prediction models with training AUCs of 0.903 [95% CI 0.86, 0.96] and 0.928 [95% CI 0.89, 0.96]. In total, from unbiased discovery LC-MS/MS, 66 peptides representing 39 proteins that may act as potential peptide biomarkers were identified in univariate and multivariate analyses.

Conclusion

Using two complementary proteomic approaches and a combination of univariate and machine learning models, a total of 181 candidate biomarker peptides corresponding to 106 proteins have been identified that may act as potential biomarkers for predicting response to treatment of PsA. Further study is required to verify and evaluate these candidate biomarkers, and we will report how these proteins map to biological processes, pathways and networks.

References

[1]Mease et al. N Engl J Med 2017; 377: 1537-1550.

[2]Gladman et al. N Engl J Med 2017; 377: 1525-1536.

[3]Breiman. Machine Learning 2001; 45: 5-32.

Acknowledgements

Study sponsored by Pfizer Inc. Medical writing support was provided by Lauren Hogarth, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests

James Waddington Employee of: Atturos, Ruoyi Zhou Employee of: Atturos, Orla Coleman Employee of: Atturos, Bruna Wundervald Employee of: Atturos, Andrew Parnell: None declared, Philip J Mease Speakers bureau: AbbVie, Amgen, Janssen, Novartis, Pfizer Inc and UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, CorEvitas, Eli Lilly, Galapagos, Gilead Sciences, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer Inc, Sun Pharma and UCB, Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Novartis, Pfizer Inc, Sun Pharma and UCB, Vinod Chandran Consultant of: AbbVie, Amgen, BMS, Eli Lilly, Janssen, Novartis, Pfizer Inc and UCB, Grant/research support from: AbbVie, Amgen, Eli Lilly, Lara Fallon Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Douglass Chapman Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Remy Pollock Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Shibing Deng Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Oliver FitzGerald Shareholder of: Atturos, Speakers bureau: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen, Novartis, Pfizer Inc and UCB, Employee of: University College Dublin, Stephen Pennington Shareholder of: Atturos, Employee of: University College Dublin

1244 The TAL Suction Retractor: A Simple Technique for Visualising the Transverse Acetabular Ligament (TAL) During Total Hip Replacement (THR) Surgery

Introduction

The transverse acetabular ligament (TAL) is an anatomical landmark that is of particular use during primary total hip replacements (THR). Visualisation is important to aid the orientation of the acetabular cup and it is a structure that can be identified in virtually every primary hip replacement surgery. We introduce a simple technique to facilitate this.

Method

A thoracic suction catheter is taped to the distal end of a blunt Hohmann’s retractor with two steristrips wrapping around the catheter and retractor leaving approximately 1-1.5cm of retractor exposed. Our preference is for a thoracic suction catheter with side holes and a proximal end which allows direct connection with the tip of the Yankauer suction. The blunt Hohmann’s retractor is used as the inferior acetabular retractor in the usual way, placed inferior to the transverse acetabular ligament, resting on the posterior ischial surface. The catheter suction tip should lie just under the TAL, in the most dependant point of the wound.

Results

The TAL suction catheter can be used continuously or intermittently to facilitate visualisation of the TAL during reaming, trialling, and acetabular cup placement. The TAL suction retractor provides suction in the most dependant point of the surgical wound, preventing unnecessary movement and facilitates a clutter-free surgical field leading to more streamlined and efficient surgery with potential reduced operative times.

Conclusions

The transverse acetabular ligament (TAL) suction retractor is a simple improvised surgical tool that makes it easier to visualise the TAL during acetabular preparation in total hip replacements.

Abstract 475: Improving liposarcoma diagnosis through cross-flow microfiltration

Introduction: Dedifferentiated liposarcoma (DDLPS) is frequently diagnosed late and patients typically respondpoorly to treatments bringing to an overall survival rate of only 10% at 10 years. Prognosis isenhanced by early detection of recurrent lesions, but current diagnostic methods rely on invasivetissue biopsies combined with whole or part-body imaging. These diagnostic and prognosticchallenges prompted us to explore the use of circulating biomolecules as potential biomarkersaccessible through bodily fluids. Extracellular Vesicles (EVs) are membrane vesicles containingproteins and nucleic acids that circulate in the blood, so they are an emerging class of easilyaccessible blood biomarkers. We recently identified extracellular vesicle EV-MDM2 as liquidbiopsy biomarker for disease identification in DDLPS. Unfortunately, due to these challenges forisolation and capture of EVs, despite the potential diagnostic and prognostic utility, the practicalrelevance of using EVs for routine analysis remains limited.

Methods: A microfluidic device was fabricated via standard soft lithography in PDMS(polydimethylsiloxane). A 5 x 5 mm2 nanocapillary array membrane (nominal capillary diameterof 0.2 µm) was sandwiched between two microchannels for a vertically aligned configuration withan injection and separation channel (each 500 µm wide and 150 µm high) perpendicular to eachother. The separation channel surface was functionalized with the anti-CD63 antibody forcapturing EVs.

Results: We present here a facile approach to fabricate and operate a micro-nanofluidic device that usescross-flow filtration to isolate and capture liposarcoma derived EVs. Our methodology integratesthe unit operations of size based separation with immunoaffinity-based capture of extracellularvesicles in the same device. The eluted media collected showed ~84% extracellular vesiclerecovery from the liposarcoma cell conditioned media and ~38% extracellular vesicle recoveryfrom dedifferentiated liposarcoma patient serum when compared to extracellular vesicle isolationand subsequent quantification by ultracentrifugation. The results reported here also show a five-fold increase in amount of critical liposarcoma relevant extracellular vesicle cargo obtained in30 minutes presenting a significant advance over existing state-of-art.

Conclusion: In conclusion we developed a cross-flow filtration micro-nanofluidic device for isolation, selectivecapture and release of liposarcoma EVs.

Citation Format: Lucia Casadei, Patricia Sarchet, Adarsh Choudhury, Shaurya Prakash, Raphael Pollock. Improving liposarcoma diagnosis through cross-flow microfiltration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 475.

Morbidity and Outcomes After Distal Pancreatectomy for Primary Retroperitoneal Sarcoma: An Analysis by the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group

BACKGROUND

Multi-visceral resection often is used in the treatment of retroperitoneal sarcoma (RPS). The morbidity after distal pancreatectomy for primary pancreatic cancer is well-documented, but the outcomes after distal pancreatectomy for primary RPS are not. This study aimed to evaluate morbidity and oncologic outcomes after distal pancreatectomy for primary RPS.

METHODS

In this study, 26 sarcoma centers that are members of the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) retrospectively identified consecutive patients who underwent distal pancreatectomy for primary RPS from 2008 to 2017. The outcomes measured were 90-day severe complications (Clavien-Dindo ≥ 3), postoperative pancreatic fistula (POPF) rate, and oncologic outcomes.

RESULTS

Between 2008 and 2017, 280 patients underwent distal pancreatectomy for primary RPS. The median tumor size was 25 cm, and the median number of organs resected, including the pancreas, was three. In 96% of the operations, R0/R1 resection was achieved. The 90-day severe complication rate was 40 %. The grades B and C POPF complication rates were respectively 19% and 5% and not associated with worse overall survival. Administration of preoperative radiation and factors to mitigate POPF did not have an impact on the risk for the development of a POPF. The RPS invaded the pancreas in 38% of the patients, and local recurrence was doubled for the patients who had a microscopic, positive pancreas margin (hazard ratio, 2.0; p = 0.042).

CONCLUSION

Distal pancreatectomy for primary RPS has acceptable morbidity and oncologic outcomes and is a reasonable approach to facilitate complete tumor resection.

Cross-flow microfiltration for isolation, selective capture and release of liposarcoma extracellular vesicles

We present a resource‐efficient approach to fabricate and operate a micro‐nanofluidic device that uses cross‐flow filtration to isolate and capture liposarcoma derived extracellular vesicles (EVs). The isolated extracellular vesicles were captured using EV‐specific protein markers to obtain vesicle enriched media, which was then eluted for further analysis. Therefore, the micro‐nanofluidic device integrates the unit operations of size‐based separation with CD63 antibody immunoaffinity‐based capture of extracellular vesicles in the same device to evaluate EV‐cargo content for liposarcoma. The eluted media collected showed ∼76% extracellular vesicle recovery from the liposarcoma cell conditioned media and ∼32% extracellular vesicle recovery from dedifferentiated liposarcoma patient serum when compared against state‐of‐art extracellular vesicle isolation and subsequent quantification by ultracentrifugation. The results reported here also show a five‐fold increase in amount of critical liposarcoma‐relevant extracellular vesicle cargo obtained in 30 min presenting a significant advance over existing state‐of‐art.

Surgical Outcome and Oncological Survival of Osteofibrous Dysplasia-Like and Classic Adamantinomas: An International Multicenter Study of 318 Cases

BACKGROUND

Osteofibrous dysplasia-like adamantinoma (OFD-AD) and classic adamantinoma (AD) are rare, neoplastic diseases with only limited data supporting current treatment protocols. We believe that our retrospective multicenter cohort study is the largest analysis of patients with adamantinoma to date. The primary purpose of this study was to describe the disease characteristics and evaluate the oncological outcomes. The secondary purpose was to identify risk factors for local recurrence after surgical treatment and propose treatment guidelines.

METHODS

Three hundred and eighteen confirmed cases of OFD-AD and AD for which primary treatment was carried out between 1985 and 2015 were submitted by 22 tertiary bone tumor centers. Proposed clinical risk factors for local recurrence such as size, type, and margins were analyzed using univariable and multivariate Cox regression analysis.

RESULTS

Of the 318 cases, 128 were OFD-AD and 190 were AD. The mean age at diagnosis was 17 years (median, 14.5 years) for OFD-AD and 32 years (median, 28 years) for AD; 53% of the patients were female. The mean tumor size in the OFD-AD and AD groups combined was 7.8 cm, measured histologically. Sixteen percent of the patients sustained a pathological fracture prior to treatment. Local recurrence was recorded in 22% of the OFD-AD cases and 24% of the AD cases. None of the recurrences in the OFD-AD group progressed to AD. Metastatic disease was found in 18% of the AD cases and fatal disease, in 11% of the AD cases. No metastatic or fatal disease was reported in the OFD-AD group. Multivariate Cox regression analysis demonstrated that uncontaminated resection margins (hazard ratio [HR] = 0.164, 95% confidence interval [CI] = 0.092 to 0.290, p < 0.001), pathological fracture (HR = 1.968, 95% CI = 1.076 to 3.600, p = 0.028), and sex (female versus male: HR = 0.535, 95% CI = 0.300 to 0.952, p = 0.033) impacted the risk of local recurrence.

CONCLUSIONS

OFD-AD and AD are parts of a disease spectrum but should be regarded as different entities. Our results support reclassification of OFD-AD into the intermediate locally aggressive category, based on the local recurrence rate of 22% and absence of metastases. In our study, metastatic disease was restricted to the AD group (an 18% rate). We advocate wide resection with uncontaminated margins including bone and involved periosteum for both OFD-AD and AD.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Multi-Layer Micro-Nanofluidic Device for Isolation and Capture of Extracellular Vesicles Derived from Liposarcoma Cell Conditioned Media

We report on isolation, capture, and subsequent elution for analysis of extracellular vesicles derived from human liposarcoma cell conditioned media, using a multi-layer micro-nanofluidic device operated with tangential flow separation. Our device integrates size-based separation followed by immunoaffinity-based capture of extracellular vesicles in the same device. For liposarcomas, this is the first report on isolating, capturing, and then eluting the extracellular vesicles using a micro-nanofluidic device. The results show a significantly higher yield of the eluted extracellular vesicles (~84%) compared to the current methods of ultracentrifugation (~6%) and ExoQuick-based separations (~16%).

Abstract 6213: Extracellular vesicles MDM2-DNA derived from dedifferentiated liposarcoma induces MMP2 production from preadipocytes

Dedifferentiated liposarcoma (DDLPS) is molecularly characterized by wt p53 and MDM2 gene amplification causing MDM2 protein over-production, the key oncogenic process in DDLPS. Commonly located in fat-bearing retroperitoneal areas, almost 60% of DDLPS patients undergo multifocal recurrence, typically amenable to palliative treatment only, and occasionally develop distant metastasis. These factors lead to an abysmal 10% 10 year overall survival rate. Tumor cell-derived extracellular vesicles (EVs) can facilitate loco-regional malignancy dissemination by depositing molecular factors that participate in the development of pre-metastatic niches for tumor cell implantation and growth. High number of MDM2 DNA molecules was identified within EVs from DDLPS patient serum (ROC vs normal; 0.95) as well as from DDLPS cell lines. This MDM2 DNA could be transferred to preadipocytes (P-a), a major and ubiquitous cellular component of the DDLPS tumor microenvironment (TME), with subsequent P-a production of matrix metalloproteinase 2 (MMP2), a critical component in the metastatic cascade. Since multifocal loco-regional DDLPS spreading is the main cause of the remarkably high lethality of this disease, a better understanding of the underlying oncogenic processes and their regulatory mechanisms is essential to improve the outcome of this devastating disease.

Citation Format: Lucia Casadei, Federica Calore, Ameya Deshmukh, Abeba Zewdu, Paolo Fadda, Danielle Braggio, Martin Wabitsch, Carlo M. Croce, Dina Lev, Raphael Pollock. Extracellular vesicles MDM2-DNA derived from dedifferentiated liposarcoma induces MMP2 production from preadipocytes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6213.

Activity of PD1 inhibitor therapy in advanced sarcoma: a single-center retrospective analysis

BACKGROUND

Sarcomas constitute a heterogeneous group of tumors with different clinical behaviors and variable responses to systemic therapies. Recent immunotherapy studies with PD1 inhibitors (PD1i) show promising results with use in certain soft-tissue sarcomas; however, the clinical and molecular features that best predict response to PD1i remain unclear.

METHODS

Demographic, imaging, histologic, and genetic sequencing data was collected for sarcoma patients who received nivolumab or pembrolizumab (PD1i) treatment at our institution between January 1st 2015 and April 23rd 2018. The primary objective was to determine progression-free survival (PFS) in patients with advanced sarcomas receiving PD1i. Secondary objectives included determining overall survival (OS) and assessment of characteristics associated with response to PD1i. Fifty-six patients who were treated with PD1i therapy met inclusion criteria for this study.

RESULTS

Partial response towards PD1i treatment was seen in 3 in 26 evaluable patients, but no complete responses were observed (overall response rate 11.5%). Within this group of patients, the 90 day PFS was found to be 48.8%. In patients in whom PD1 expression was known, there was a statistically significant positive correlation between expression of PD1 and longer PFS and OS rates. Patients that were treated with more than four cycles of PD1i therapy were also more likely to have a greater OS.

CONCLUSIONS

This study suggests activity of PD1i in a pretreated cohort of advanced sarcoma patients, particularly for the subset of patients with PD1 positive tumors. Our results highlight the importance of further research to better target the optimal patient population and markers of response.

Targeted muscle reinnervation in oncologic amputees: Early experience of a novel institutional protocol

BACKGROUND

We describe a multidisciplinary approach for comprehensive care of amputees with concurrent targeted muscle reinnervation (TMR) at the time of amputation.

METHODS

Our TMR cohort was compared to a cross-sectional sample of unselected oncologic amputees not treated at our institution (N = 58). Patient-Reported Outcomes Measurement Information System (NRS, PROMIS) were used to assess postamputation pain.

RESULTS

Thirty-one patients underwent amputation with concurrent TMR during the study; 27 patients completed pain surveys; 15 had greater than 1 year follow-up (mean follow-up 14.7 months). Neuroma symptoms occurred significantly less frequently and with less intensity among the TMR cohort. Mean differences for PROMIS pain intensity, behavior, and interference for phantom limb pain (PLP) were 5.855 (95%CI 1.159-10.55; P = .015), 5.896 (95%CI 0.492-11.30; P = .033), and 7.435 (95%CI 1.797-13.07; P = .011) respectively, with lower scores for TMR cohort. For residual limb pain, PROMIS pain intensity, behavior, and interference mean differences were 5.477 (95%CI 0.528-10.42; P = .031), 6.195 (95%CI 0.705-11.69; P = .028), and 6.816 (95%CI 1.438-12.2; P = .014), respectively. Fifty-six percent took opioids before amputation compared to 22% at 1 year postoperatively.

CONCLUSIONS

Multidisciplinary care of amputees including concurrent amputation and TMR, multimodal postoperative pain management, amputee-centered rehabilitation, and peer support demonstrates reduced incidence and severity of neuroma and PLP.

Delays in the diagnosis and treatment of bone and joint tuberculosis in the United Kingdom

Aims

Tuberculosis (TB) infection of bones and joints accounts for 6.7% of TB cases in England, and is associated with significant morbidity and disability. Public Health England reports that patients with TB experience delays in diagnosis and treatment. Our aims were to determine the demographics, presentation and investigation of patients with a TB infection of bones and joints, to help doctors assessing potential cases and to identify avoidable delays.

Patients and Methods

This was a retrospective observational study of all adults with positive TB cultures on specimens taken at a tertiary orthopaedic centre between June 2012 and May 2014. A laboratory information system search identified the patients. The demographics, clinical presentation, radiology, histopathology and key clinical dates were obtained from medical records.

Results

A total of 31 adult patients were identified. Their median age was 37 years (interquartile range (IQR): 29 to 53); 21 (68%) were male; 89% were migrants. The main sites affected were joints (10, 32%), the spine (8, 26%) and long bones (6, 19%); 8 (26%) had multifocal disease. The most common presenting symptoms were pain (29/31, 94%) and swelling (26/28, 93%). ‘Typical’ symptoms of TB, such as fever, sweats and weight loss, were uncommon. Patients waited a median of seven months (IQR 3 to 13.5) between the onset of symptoms and referral to the tertiary centre and 2.3 months (IQR 1.6 to 3.4.)) between referral and starting treatment. Radiology suggested TB in 26 (84%), but in seven patients (23%) the initial biopsy specimens were not sent for mycobacterial culture, necessitating a second biopsy. Rapid Polymerase Chain Reaction-based testing for TB using Xpert MTB/RIF was performed in five patients; 4 (80%) tested positive for TB. These patients had a reduced time between the diagnostic biopsy and starting treatment than those whose samples were not tested (median eight days versus 36 days, p = 0.016).

Conclusion

Patients with bone and joint TB experience delays in diagnosis and treatment, some of which are avoidable. Maintaining a high index of clinical suspicion and sending specimens for mycobacterial culture are crucial to avoid missing cases. Rapid diagnostic tests reduce delays and should be performed on patients with radiological features of TB. Cite this article: Bone Joint J 2018;100-B:119–24.

Mocetinostat combined with gemcitabine for the treatment of leiomyosarcoma: Preclinical correlates

Leiomyosarcoma (LMS) is a malignant soft tissue sarcoma (STS) with a dismal prognosis following metastatic disease. Chemotherapeutic intervention has demonstrated to have modest clinical efficacy with no curative potential in LMS patients. Previously, we demonstrated pan-HDAC inhibition to have a superior effect in various complex karyotypic sarcomas. In this study, our goal is to evaluate the therapeutic efficacy of mocetinostat alone and in combination with gemcitabine in LMS. Human leiomyosarcoma (LMS) cell lines were used for in vitro and in vivo studies. Compounds tested included the class I HDAC inhibitor, mocetinostat, and nucleoside analog, gemcitabine. MTS and clonogenic assays were used to evaluate the effect of mocetinostat on LMS cell growth. Cleaved caspase 3/7 analysis was used to determine the effects of mocetinostat on apoptosis. Compusyn software was used to determine in vitro synergy studies for the combination of mocetinostat plus gemcitabine. A LMS xenograft model in SCID mice was used to test the impact of mocetinostat alone, gemcitabine alone and the combination of mocetinostat plus gemcitabine. Mocetinostat abrogated LMS cell growth and clonogenic potential, and enhanced apoptosis in LMS cell lines. The combination of mocetinostat plus gemcitabine exhibited a synergistic effect in LMS cells in vitro. Similarly, mocetinostat combined with gemcitabine resulted in superior anti-LMS effects in vivo. Mocetinostat reduced the expression of gemcitabine-resistance markers RRM1, RRM2, and increased the expression of gemcitabine-sensitivity marker, hENT1, in LMS cells. LMS are aggressive, metastatic tumors with poor prognosis where effective therapeutic interventions are wanting. Our studies demonstrate the potential utility of mocetinostat combined with gemcitabine for the treatment of LMS.

Outcome of lumbar spinal fusion surgery in obese patients

The aim of this study was to determine whether obesity affects pain, surgical and functional outcomes following lumbar spinal fusion for low back pain (LBP).

A systematic literature review and meta-analysis was made of those studies that compared the outcome of lumbar spinal fusion for LBP in obese and non-obese patients. A total of 17 studies were included in the meta-analysis. There was no difference in the pain and functional outcomes. Lumbar spinal fusion in the obese patient resulted in a statistically significantly greater intra-operative blood loss (weighted mean difference: 54.04 ml; 95% confidence interval (CI) 15.08 to 93.00; n = 112; p = 0.007) more complications (odds ratio: 1.91; 95% CI 1.68 to 2.18; n = 43858; p < 0.001) and longer duration of surgery (25.75 mins; 95% CI 15.61 to 35.90; n = 258; p < 0.001). Obese patients have greater intra-operative blood loss, more complications and longer duration of surgery but pain and functional outcome are similar to non-obese patients. Based on these results, obesity is not a contraindication to lumbar spinal fusion.

Cite this article: Bone Joint J 2015;97-B:1395–1404.

Abstract LB-251: Histone deacetylase inhibition for the treatment of epithelioid sarcoma; novel cross talk between epigenetic components

Objective

Enhanced knowledge of epithelioid sarcoma (ES) molecular determinants will hopefully aid the development of urgently needed targeted therapies. The hallmark loss of INI1 causes a disruption in epigenetics, potentially contributing to the development of the disease. Recently, we have demonstrated that HDAC inhibitors (HDACi) to have efficacious value for the treatment various genetically complex sarcomas. Here, we aim to evaluate the potential therapeutic efficacy of HDACi in ES.

Methods

Three ES cell lines were used for this study: Epi-544, HS-ES, VAESBJ. MTS and clonogenic assays were utilized to evaluate the effect of HDACi on cell line growth. Cell cycle FACS and annexin V PI/FACS analysis with WB for cleaved caspase 3 were used to determine the effects of HDACi on cell cycle and apoptosis, respectively. In vivo growth effects of HDACi were evaluated using SCID mouse ES xenograft models. An Illumina gene array was used to evaluate HDACi-induced gene change.

Results

HDACi inhibited ES cell growth and colony formation. HDACi induced G2 cell cycle arrest and enhanced apoptosis in all ES cell lines tested. Similarly, HDACi abrogated ES xenograft growth and increased apoptosis in vivo. Due to the HDACi mechanisms of function, one of the major

consequences of this therapy is gene expression modulation. Using an Illumina gene array, we sought to identify genes responsible for the in vitro and in vivo anti-ES effects observed. Array analysis showed Survivin be significantly down-regulated in response to HDACi treatment. HDACi-induced decrease of Survivin was confirmed via WB. For enrichment analysis of our genes set with published annotated gene signatures, the Molecular Signatures Database (MSigDB) was used. MSigDB analysis identified a curated gene set of regulated genes after EZH2 knockdown (KD) with significant commonality of our gene array. We demonstrated HDACi-induced decrease of EZH2. EZH2 KD resulted in reduced cell growth and increased apoptosis in VAESBJ cells.

Conclusion

HDACs play a role in the progression of ES, where HDACi abrogate ES cell growth and enhance apoptosis in vitro and in vivo. Gene array analysis revealed various genes modulated by HDACi that may contribute to the progression of the disease. Anti-ES effects may be in part through the HDACi-induced repression of EZH2.

Citation Format: Gonzalo Lopez, Yechun Song, Dennis Ruder, Chad Creighton Creighton, Svetlana Bolshakov, Xiaoli Zhang, Dina Lev, Raphael Pollock. Histone deacetylase inhibition for the treatment of epithelioid sarcoma; novel cross talk between epigenetic components. [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 LB-251. doi:10.1158/1538-7445.AM2015-LB-251

Accuracy of preoperative percutaneous biopsy for the diagnosis of retroperitoneal liposarcoma subtypes

BACKGROUND

Surgery is the primary treatment for all subtypes of retroperitoneal liposarcoma, but neoadjuvant therapy may be warranted in cases of dedifferentiated liposarcoma (DDLS), which has an increased risk of recurrence and metastasis. Therefore, an accurate subtype-specific diagnosis is vital for appropriate consideration of neoadjuvant therapy. Previous studies assessing the subtype-specific accuracy of percutaneous biopsy are limited. We aimed to analyze the accuracy of preoperative percutaneous biopsy in the subtype-specific diagnosis of retroperitoneal liposarcoma and thus the reliability of percutaneous biopsy in guiding decisions about neoadjuvant treatment.

METHODS

We retrospectively reviewed the medical records, including the pathologic reports, interventional radiology reports, and operative reports, of patients registered in the retroperitoneal/well-differentiated liposarcoma (WDLS/DDLS) database at The University of Texas MD Anderson Cancer Center between 1993 and 2013.

RESULTS

We identified 120 patients who underwent 137 preoperative percutaneous biopsies followed by surgical resections. Pathologic examination following resection indicated that 74 of the patients had WDLS and 63 had DDLS. The overall diagnostic accuracy of percutaneous biopsy for identifying the subtype of liposarcoma was 62.8 % (86/137); the accuracy for identifying WDLS was significantly higher (85.1 %; 63/74) than that for identifying DDLS (36.5 %; 23/63) (p < 0.01).

CONCLUSIONS

Percutaneous biopsy has low accuracy in the diagnosis of retroperitoneal DDLS. This can potentially mislead physicians in the decision to implement neoadjuvant treatment. When developing treatment strategies, including clinical trials for patients with retroperitoneal liposarcoma, physicians should carefully consider the low accuracy of percutaneous biopsy in detecting DDLS.

The outcome of resection of the distal ulna for tumour without soft-tissue or prosthetic reconstruction

In patients with a tumour affecting the distal ulna it is difficult to preserve the function of the wrist following extensive local resection. We report the outcome of 12 patients (nine female, three male) who underwent excision of the distal ulna without local soft-tissue reconstruction. In six patients, an aggressive benign tumour was present and six had a malignant tumour. At a mean follow-up of 64 months (15 to 132) the mean Musculoskeletal Tumour score was 64% (40% to 93%) and the mean DASH score was 35 (10 to 80). The radiological appearances were satisfactory in most patients. Local recurrence occurred in one patient with benign disease and two with malignant disease. The functional outcome was thus satisfactory at a mean follow-up in excess of five years, with a relatively low rate of complications. The authors conclude that complex reconstructive soft-tissue procedures may not be needed in these patients.

Abstract 2770: MGAT5B expression in malignant peripheral nerve sheath tumors and RAS-mutated tumors promote maturation of tyrosine kinase receptors through a PI3K/AKT/MGAT5B mechanism

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that occur either sporadically or in patients with Neurofibromatosis type I. Surgery is the main stay of treatment, however, due to the invasive growth, propensity to metastasis, limited sensitivity to chemotherapy and radiation therapy, 5-year survival rates is only 20%-50%. Recent studies have identified several altered intracellular signal transduction cascades and deregulated expression of kinase receptors in MPNSTs, posing the possibility of personalized, targeted therapeutics for these diseases. Kinase receptors depend on the glycosylation for stabilization, maturation, transport onto the cell surface, phosphorylation and activation. Aberrant glycosylation to stabilize the expression of kinase receptors on the cell surface is associated with many cancers. The appropriate and accurate modification of glycans to proteins mainly depends on the action of highly specific and precisely located enzymes known as glycosyltransferases and glycosidases in different tissues and cells. In this report, we found that glycoproteins were highly expressed in MPNST cell lines compared with normal Schwann cells (NSC). We used the Human Glycosylation PCR Array to profile the expression of 84 key genes encoding enzymes that regulate protein glycosylation. We did not identify any change in glycosidase mRNA expression levels, whereas multiple glycosyltransferases (B4GALT5, FUT8, MGAT3, MGAT4A, MGAT5, MGAT5B, GALNT13, GALNT14, POMT1, ST8SIA2) were overexpressed in different MPNST cell lines. This is especially true for MGAT5B, a glycosyltransferase that promotes N-linked or O-linked protein glycosylation, which was highly expressed in all MPNST cell lines, many MPNST clinical specimens, as well as colon and pancreatic cancer cell lines with K-ras mutations. Exogenous expression of K-ras (G12V) significantly upregulated MGAT5B expression to promote glycosylation of several tyrosine kinase receptors, whereas knockdown of MGAT5B significantly inhibited the glycosylation and phosphorylation of these kinase receptors. Moreover, we found AKT interacted with and phosphorylated Ser192 in MGAT5B to promote MGAT5B transport from the cytoplasm to the Golgi apparatus. Mutated MGAT5BS192A protein stayed in the cytoplasm significantly attenuated experimental lung tumor metastasis in vivo. Furthermore treatment of MPNST cells with the PI3K inhibitor Ly294002 inhibited MGAT5B glycosyltransferase activity to attenuate glycosylation and phosphorylation of tyrosine kinase receptors. Taken together, these data suggest that RAS-mediated MGAT5B expression plays a critical role in promoting glycosylation of many kinase receptors. Targeting MGAT5B-mediated protein glycosylation may open a new therapeutic window for the treatment of MPNSTs and RAS-related malignancies.

Citation Format: Quansheng Zhu, Hui Shang, Yechun Song, Yi Zhang, Raphael Pollock, Steven Hsesheng Lin. MGAT5B expression in malignant peripheral nerve sheath tumors and RAS-mutated tumors promote maturation of tyrosine kinase receptors through a PI3K/AKT/MGAT5B mechanism. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2770. doi:10.1158/1538-7445.AM2014-2770

Splenectomy in patients with myeloproliferative neoplasms: efficacy, complications and impact on survival and transformation

Splenectomy may be an effective therapeutic option for treating massive splenomegaly in patients with myeloproliferative neoplasms (MPNs). There are still limited data on its short- and long-term benefits and risks. Efficacy and short-term complications were analyzed in 94 patients with different MPNs who underwent splenectomy at M. D. Anderson Cancer Center. The long-term impact of splenectomy on overall survival (OS) and transformation free survival (TFS) was evaluated in 461 patients with myelofibrosis (MF) seen at M. D. Anderson, including 50 who underwent splenectomy during disease evolution. Splenectomy improved anemia and thrombocytopenia in 47% and 66% of patients, respectively. The most common complications were leukocytosis (76%), thrombocytosis (43%) and venous thromboembolism (16%). Post-operative mortality was 5%. Among patients with MF, splenectomy during disease evolution was associated with decreased OS (hazard ratio [HR] = 2.17, p < 0.0001) and TFS (HR = 2.17, p < 0.0001). This effect was independent of the Dynamic International Prognostic Scoring System. Splenectomy is a possible therapeutic option for patients with MF and other MPNs, and its greatest benefits are related to improvement in spleen pain and discomfort, anemia and thrombocytopenia. However, in patients with MF it appears to be associated with increased mortality.

Abstract 4258: Targeting MGAT5B-mediated glycosylation of kinase receptors for the treatment of malignant peripheral nerve sheath tumors and RAS-related malignancies

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that occur either sporadically or in patients with Neurofibromatosis type I. Surgery is the main stay of treatment, however, due to the invasive growth, propensity to metastasis, limited sensitivity to chemotherapy and radiation, 5-year survival rates is only 20%-50%. Recent work has identified several altered intracellular signal transduction cascades and deregulated kinase receptors, posing the possibility of personalized, targeted therapeutics. Kinase receptors depend on the glycosylation for stabilization, maturation, transportation onto the cell surface, phosphorylation and activation, and aberrant glycosylation to stabilize the expression of kinase receptors on the cell surface is associated with cancers. The appropriate and accurate modification of glycan to proteins mainly depends on the action of highly specific and precisely located enzymes known as glycosyltransferases and glycosidases in different tissues and cells. In this report, glycoproteins were highly expressed in MPNST cell lines compared with normal Schwann cells (NSC). Human Glycosylation PCR Array was used to profile the expression of 84 key genes encoding enzymes to regulate the glycosylation of proteins. Compared with NSC, we did not find any change in the mRNA expression levels of glycosidases, however, multiple glycosyltransferases (B4GALT5, FUT8, MGAT3, MGAT4A, MGAT5, MGAT5B, GALNT13, GALNT14, POMT1, ST8SIA2) were overexpressed in some MPNST cell lines, especially MGAT5B, one of glycosyltransferases to promote N-linked or O-linked glycosylation of proteins was highly expressed in MPNST cell lines and clinical specimens, and colon and pancreatic cancer cell lines with K-ras mutations. Exogenous expressing K-ras (G12V) significantly upregulated the expression of MGAT5B. The expression levels of MGAT5B were correlated with RAS kinase activity. We also found AKT interacted with MGAT5B and phosphorylation of S192 of MGAT5B promoted transportation from the cytoplasm into the Golgi apparatus and mutated MGAT5BS192A expression was distributed in the ER and cytoplasm. Experimental tumor lung metastasis was significantly inhibited in MPNST cells expressing MGAT5BS192A. Furthermore, we found that transient or stable knockdown of MGAT5B significantly attenuated the glycosylation and phosphorylation of kinase receptors to block their signaling, arrested cells in G1 phase and altered the morphology of MPNST cell lines. Taken together, these data suggest that RAS-driving the expression of MGAT5B plays a critical role in promoting glycosylation of kinase receptors to mediate their intracellular signaling and targeting MGAT5B-mediated glycosylation of kinase receptors may open a new therapeutic window for MPNSTs and RAS-related malignancies

Citation Format: Quansheng Zhu, Yechun Song, Hui Shang, Thresa Nguyen, Svetlana Bolshakov, Xiaoyan Ma, Alexander Lazar, Raphael Pollock, Dina Chelouche Lev. Targeting MGAT5B-mediated glycosylation of kinase receptors for the treatment of malignant peripheral nerve sheath tumors and RAS-related malignancies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4258. doi:10.1158/1538-7445.AM2013-4258

Identification of the biopsy track in musculoskeletal tumour surgery: a novel technique using India ink

Local recurrence along the biopsy track is a known complication of percutaneous needle biopsy of malignant musculoskeletal tumours. In order to completely excise the track with the tumour its identification is essential, but this becomes increasingly difficult over time. In an initial prospective study, 22 of 45 patients (48.8%) identified over a three-month period, treated by resection of a musculoskeletal tumour, had an unidentifiable biopsy site at operation, with identification statistically more difficult after 50 days. We therefore introduced the practice of marking the biopsy site with India ink. In all 55 patients undergoing this procedure, the biopsy track was identified pre-operatively (100%); this difference was statistically significant. We recommend this technique as a safe, easy and accurate means of ensuring adequate excision of the biopsy track.

Abstract 4577: Targeting N-glycosylation of tyrosine kinase receptors for preventing tumorigenesis and malignant transformation of neurofibromatosis type I

Neurofibromatosis type I (NF1) is a dominantly inherited disease affecting 1 in every 2,500 to 3,000 individuals, representing the most common familial cancer predisposition syndrome. The hallmark of clinical manifestation of NF1 is the development of multiple neurofibromas, which are highly heterotypic benign tumors of peripheral nerve sheath mainly composed of immature Schwann cells, fibroblasts, perineurial and inflammatory matrix. NF1 patients are also at high risk for the development of certain maligancies such as pheochromocytomas, childhood myeloid leukemias, neuroblastomas, rhabdomyosarcomas, and malignant peripheral nerve sheath tumors (MPNSTs). Because of the potential involvement of underlying nerves and blood vessels, surgical removal of tumors is not always an option. Once progressing to MPNSTs, although the resection is possible, most patients will eventually relapse locally or systemically. There is no effective treatment for NF1, nor effective approaches for predicting or preventing the occurrence of devastating complications. Thus, to develop agents for preventing or reversing the tumorigenesis and malignant transformation of NF1 are critically needed. In this report, we found HGF, c-MET, EGF and EGFR are aberrantly expressed in clinical specimens of neurofibromas and MPNSTs with NF and that autocrine and/or paracrine HGF/c-MET and EGF/EGFR loops promote MPSNT cell migration and invasion in vitro (Fig1). We also found that the loss of Nf1 in neurofibromas and MPNSTs results in hyperactive of Ras (Fig2). Compared with normal Schwann cells, MPNST cells express more N-glycoproteins and display different N-glycoprotein signatures (Fig3). In order to confirm our hypothesis, we treated cells with Tunicamycin, or 2-DG (N-glycosylation inhibitors) respectively in variable doses for different time. We found that both Tunicamycin and 2-DG inhibited the proliferation and promoted apoptosis of MPNST cell lines but had no effect on normal human Schwann cells (Fig4); inhibited the glycosylation and phosphorylation of EGFR and c-MET and impaired receptor-mediated MEK-ERK1/2 and PI3K-AKT signaling in a dose-dependent manner (Fig5). Moreover, 2-DG inhibited the maturation of c-MET as demonstrated by the intact premature chain, failing to cleave into one mature α-chain and another mature α-chain. In addition, 2-DG inhibited the translocation of the receptors from the cytoplasm onto the cell surface and retained receptors in the ER and Golgi apparatus (Fig6). To date, 2-DG inhibition of N-glycosylation and phosphorylation of tyrosine kinase receptors has not been reported. These novel findings prompted us to explore whether 2-DG disrupts Ras-directed N-glycosylation of tyrosine receptors in Schwann cell progenitors and tumor cells and to evaluate its roles in preventing the tumorigenesis and malignant transformation of NF1.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4577. doi:1538-7445.AM2012-4577

Incorporation of adjuvant therapy into the multimodality management of gastrointestinal stromal tumors of the stomach in the United States

BACKGROUND

Gastrointestinal stromal tumors (GIST) treatment changed considerably with introduction of imatinib in 2001 and reports of early successes. However, little is known about imatinib incorporation into practice. Our objective was to examine the integration of adjuvant systemic therapy into GIST management.

METHODS

Patients with gastric GIST were identified (n = 4508) from the National Cancer Data Base (2001-2007). Separate regression models were developed to examine factors associated with adjuvant and neoadjuvant therapy use.

RESULTS

A total of 3050 patients underwent surgical resection. From 2001-2003 to 2006-2007, use of adjuvant therapy increased from 29 to 47% (P < 0.001). Patients were less likely to receive adjuvant therapy if tumors were <3 cm, low grade, had negative margins, were treated at low-volume centers, or were diagnosed during 2001-2003 (P < 0.01). Adjuvant systemic therapy for lesions <3 cm also increased (17 to 25%, P = 0.001). For high-risk GISTs, adjuvant therapy use increased from 41 to 58% overall, with increases of 46 to 70% at high-volume centers and 40 to 48% at low-volume centers (P < 0.001). Neoadjuvant therapy increased from 0 to 8%; patients were more likely to receive neoadjuvant treatment if their tumor was >6 cm, treated at high-volume centers, or were diagnosed during 2006-2007 (P < 0.001).

CONCLUSIONS

Adjuvant systemic therapy use for GISTs was increasing and widespread prior to FDA approval of adjuvant imatinib, suggesting that contemporaneous advances in management of advanced GIST were being simultaneously and rapidly translated into the adjuvant setting. As relatively costly therapies are integrated into practice, more robust tracking systems are needed to monitor the incorporation of new treatments.

Efficacy of less invasive posterior lumbar interbody fusion as revision surgery for patients with recurrent symptoms after discectomy

Recurrence of back or leg pain after discectomy is a well-recognised problem with an incidence of up to 28%. Once conservative measures have failed, several surgical options are available and have been tried with varying degrees of success. In this study, 42 patients with recurrent symptoms after discectomy underwent less invasive posterior lumbar interbody fusion (LI-PLIF). Clinical outcome was measured using the Oswestry Disability Index (ODI), Short Form 36 (SF-36) questionnaires and visual analogue scales for back (VAS-BP) and leg pain (VAS-LP). There was a statistically significant improvement in all outcome measures (p < 0.001). The debate around which procedure is the most effective for these patients remains controversial. Our results show that LI-PLIF is as effective as any other surgical procedure. However, given that it is less invasive, we feel that it should be considered as the preferred option.

Unique patterns of metastases in common and rare types of malignancy

This review on the unique patterns of metastases by common and rare types of cancer addresses regional lymphatic metastases but also demonstrates general principles by consideration of vital organ metastases. These general features of successfully treated metastases are relationships to basic biological behavior as illustrated by disease-free interval, organ-specific behavior, oligo-metastatic presentation, genetic control of the metastatic pattern, careful selection of patients for surgical resection, and the necessity of complete resection of the few patients eligible for long-term survival after resection of vital organ metastasis. Lymph node metastases, while illustrating these general features, are not related to overall survival because lymph node metastases themselves do not destroy a vital organ function, and therefore have no causal relationship to overall survival. When a cancer cell spreads to a regional lymph node, does it also simultaneously spread to the systemic site or sites? Alternatively, does the cancer spread to the regional lymph node first and then it subsequently spreads to the distant site(s) after an incubation period of growth in the lymph node? Of course, if the cancer is in its incubation stage in the lymph node, then removal of the lymph node in the majority of cases with cancer cells may be curative. The data from the sentinel lymph node era, particularly in melanoma and breast cancer, is consistent with the spectrum theory of cancer progression to the sentinel lymph node in the majority of cases prior to distant metastasis. Perhaps, different subsets of cancer may be better defined with relevant biomarkers so that mechanisms of metastasis can be more accurately defined on a molecular and genomic level.

Proximal humeral replacement using a fixed-fulcrum endoprosthesis

Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%). Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18). Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation.

Custom-made endoprostheses for the femoral amputation stump: an alternative to hip disarticulation in tumour surgery

Disarticulation of the hip in patients with high-grade tumours in the upper thigh results in significant morbidity. In patients with no disease of the proximal soft tissue a femoral stump may be preserved, leaving a fulcrum for movement and weight-bearing. We reviewed nine patients in whom the oncological decision would normally be to disarticulate, but who were treated by implantation of an endoprosthesis in order to create a functioning femoral stump. The surgery was undertaken for chondrosarcoma in four patients, pleomorphic sarcoma in three, osteosarcoma in one and fibrous dysplasia in one. At follow-up at a mean of 80 months (34 to 132), seven patients were alive and free from disease, one had died from lung metastases and another from a myocardial infarction. The mean functional outcome assessment was 50 (musculoskeletal tumor society), 50 and 60 (physical and mental Short-form 36 scores). Implantation of an endoprosthesis into the stump in carefully selected patients allows fitting of an above-knee prosthesis and improves wellbeing and the functional outcome.

Cartilage repair: A review of Stanmore experience in the treatment of osteochondral defects in the knee with various surgical techniques

Articular cartilage damage in the young adult knee, if left untreated, it may proceed to degenerative osteoarthritis and is a serious cause of disability and loss of function. Surgical cartilage repair of an osteochondral defect can give the patient significant relief from symptoms and preserve the functional life of the joint. Several techniques including bone marrow stimulation, cartilage tissue based therapy, cartilage cell seeded therapies and osteotomies have been described in the literature with varying results. Established techniques rely mainly on the formation of fibro-cartilage, which has been shown to degenerate over time due to shear forces. The implantation of autologous cultured chondrocytes into an osteochondral defect, may replace damaged cartilage with hyaline or hyaline-like cartilage. This clinical review assesses current surgical techniques and makes recommendations on the most appropriate method of cartilage repair when managing symptomatic osteochondral defects of the knee. We also discuss the experience with the technique of autologous chondrocyte implantation at our institution over the past 11 years.

An integrated study of aberrant gene copy number and gene expression in GIST and LMS

Increased chromosomal instability that alters the gene copy numbers throughout the genome is known to have a role in molecular pathogenesis of tumors. The impact of gene dosage effect to the expression levels of genes in GIST and LMS is unknown. In this paper, we used a combination of array comparative genomic hybridization (aCGH) and gene expression data to gain insights into the interplay of structural and functional changes of the genome in GIST and LMSs. We identified specific target genes that change their expression due to the gene dosage effect. Statistical analysis identified four chromosomal regions, 1p, 14q, 15q, and 22q, where both copy number and mRNA expression were significantly different between the tumor types. Multi-dimensional scaling (MDS) analysis showed that the gene expression profiles of these four regions accurately distinguish GIST and LMS. In addition, the gene dosage sensitive genes in these regions are differently involved in several tumor growth promoting pathways, implying that there are different mechanisms underlying the GIST and LMS carcinogenesis. Integration of aCGH and gene expression data has not only provided insights into how DNA copy number variations affect the gene expression patterns in these cancers, but also proves to be a promising method to choose biologically relevant biomarkers.

The early results of joint-sparing proximal tibial replacement for primary bone tumours, using extracortical plate fixation

This paper describes the preliminary results of a proximal tibial endoprosthesis which spares the knee joint and enables retention of the natural articulation by replacing part of the tibial metaphysis and diaphysis. In eight patients who had a primary malignant bone tumour of the proximal tibia, the distal stem, which had a hydroxyapatite-coated collar to improve fixation, was cemented into the medullary canal. The proximal end had hydroxyapatite-coated extracortical plates which were secured to the remaining proximal tibial metaphysis using cortical screws. The mean age of the patients at operation was 28.9 years (8 to 43) and the mean follow-up was for 35 months (4 to 48). The mean Musculoskeletal Tumour Society score was 79% (57% to 90%), the mean Oxford Knee score was 40 points of 48 (36 to 46) and the mean knee flexion was 112° (100° to 120°). In one patient, revision to a below-knee amputation through the prosthesis was required because of recurrence of the tumour. Another patient sustained a periprosthetic fracture which healed with a painful malunion. This was revised to a further endoprosthesis which replaced the knee.

In the remaining six patients the prosthesis allowed preservation of the knee joint with good function and no early evidence of loosening. Further follow-up is required to assess the longevity of these prostheses.

Resection of pulmonary and extrapulmonary sarcomatous metastases is associated with long-term survival

BACKGROUND

The presence of extrapulmonary sarcomatous metastases has traditionally been a contraindication for the resection of pulmonary metastases. We, therefore, reviewed our experience with resection of pulmonary metastases in patients who had documented extrapulmonary metastases to determine long-term outcome.

METHODS

From 1998 to 2006, 234 patients underwent pulmonary metastasectomy. They were grouped as follows: group A (lung metastasectomy only); group B1 (with either synchronous or prior extrapulmonary metastasectomy); group B2 (with nonsurgical treatment of synchronous or prior extrapulmonary metastases); group C1 (with later extrapulmonary metastasectomy); group C2 (with later extrapulmonary metastasis which was not resected).

RESULTS

Groups A, B1, and B2 consisted of 147 (62.8%), 26 (11.1%), and 13 (5.6%) patients, respectively. The median survival from lung metastasectomy date was 35.5, 37.8, and 13.5 months in groups A, B1, and B2, respectively. Comparison among the three groups showed no significant survival difference in groups A versus B1 (p = 0.96), but a survival difference was found comparing groups A versus B2 (p < 0.001) and B1 versus B2 (p < 0.001). Prognostic factors for increased survival included 3 or greater redo pulmonary operations, greater than 12 month mean time between pulmonary recurrences, greater than 24 month mean time between extrathoracic recurrences, and a prolonged disease-free interval. Prognostic factors for decreased survival included 3 or greater pulmonary metastases and group B2 patients.

CONCLUSIONS

These results suggest extrapulmonary metastases should no longer be viewed as a contraindication to resection of sarcomatous pulmonary metastases. Long-term survival can be achieved when a complete resection is possible for both the pulmonary and extrapulmonary metastases.