Can DNA Methylation Profiling Classify Histologic Subtypes and Grades in Soft Tissue Sarcoma?

BACKGROUND: A clear classification of the subtype and grade of soft tissue sarcoma is important for predicting prognosis and establishing treatment strategies. However, the rarity and heterogeneity of these tumors often make diagnosis difficult. In addition, it remains challenging to predict the response to chemotherapy and prognosis. Thus, we need a new method to help diagnose soft tissue sarcomas and determine treatment strategies in conjunction with traditional methods. Genetic alterations can be found in some subtypes of soft tissue sarcoma, but many other types show dysregulated gene expression attributed to epigenetic changes, such as DNA methylation status. However, research on DNA methylation profiles in soft tissue sarcoma is still insufficient to provide information to assist in diagnosis and therapeutic decisions. QUESTIONS/PURPOSES: (1) Do DNA methylation profiles differ between normal tissue and soft tissue sarcoma? (2) Do DNA methylation profiles vary between different histologic subtypes of soft tissue sarcoma? (3) Do DNA methylation profiles differ based on tumor grade? METHODS: Between January 2019 and December 2022, we treated 85 patients for soft tissue sarcomas. We considered patients whose specimens were approved for pilot research by the Human Biobank of St. Vincent's Hospital, The Catholic University of Korea, as potentially eligible. Based on this, 41% (35 patients) were eligible; 1% (one patient) was excluded because of gender mismatch between clinical and genetic data after controlling for data quality. Finally, 39 specimens (34 soft tissue sarcomas and five normal samples) were included from 34 patients who had clinical data. All tissue samples were collected intraoperatively. The five normal tissue samples were from muscle tissues. There were 20 female patients and 14 male patients, with a median age of 58 years (range 19 to 82 years). Genomic DNA was extracted from frozen tissue, and DNA methylation profiles were obtained. Genomic annotation of DNA methylation sites and hierarchical cluster analysis were performed to interpret results from DNA methylation profiling. A t-test was used to analyze different methylation probes. Benjamini-Hochberg-adjusted p value calculations were used to account for bias resulting from evaluating thousands of methylation sites. RESULTS: The most common histologic subtypes were liposarcoma (n = 10) and leiomyosarcoma (n = 9). The tumor grade was Fédération Nationale des Centres de Lutte Contre Le Cancer Grades 1, 2, and 3 in 3, 15, and 16 patients, respectively. DNA methylation profiling demonstrated differences between soft tissue sarcoma and normal tissue as 21,188 cytosine-phosphate-guanine sites. Despite the small number of samples, 72 of these sites showed an adjusted p value of < 0.000001, suggesting a low probability of statistical errors. Among the 72 sites, 70 exhibited a hypermethylation pattern in soft tissue sarcoma, with only two sites showing a hypomethylation pattern. Thirty of 34 soft tissue sarcomas were distinguished from normal samples using hierarchical cluster analysis. There was a different methylation pattern between leiomyosarcoma and liposarcoma at 7445 sites. Using the data, hierarchical clustering analysis showed that liposarcoma was distinguished from leiomyosarcoma. When we used the same approach and included other subtypes with three or more samples, only leiomyosarcoma and myxofibrosarcoma were separated from the other subtypes, while liposarcoma and alveolar soft-part sarcoma were mixed with the others. When comparing DNA methylation profiles between low-grade (Grade 1) and high-grade (Grades 2 and 3) soft tissue sarcomas, a difference in methylation pattern was observed at 144 cytosine-phosphate-guanine sites. Among these, 132 cytosine-phosphate-guanine sites exhibited hypermethylation in the high-grade group compared with the low-grade group. Hierarchical clustering analysis showed a division into two groups, with most high-grade sarcomas (28 of 31) separated from the low-grade group and few (3 out of 31) clustered together with the low-grade group. However, three high-grade soft tissue sarcomas were grouped with the Grade 1 cluster, and all of these sarcomas were Grade 2. When comparing Grades 1 and 2 to Grade 3, Grade 3 tumors were separated from Grades 1 and 2. CONCLUSION: We observed a different DNA methylation pattern between soft tissue sarcomas and normal tissues. Liposarcoma was distinguished from leiomyosarcoma using methylation profiling. High-grade soft tissue sarcoma samples showed a hypermethylation pattern compared with low-grade ones. Our findings indicate the need for research using methylation profiling to better understand the diverse biological characteristics of soft tissue sarcoma. Such research should include studies with sufficient samples and a variety of subtypes, as well as analyses of the expression and function of related genes. Additionally, efforts to link this research with clinical data related to treatment and prognosis are necessary. LEVEL OF EVIDENCE: Level III, diagnostic study.

Percutaneous Cementoplasty for the Pelvis in Bone Metastasis: 12-Year Experience.

BACKGROUND: In advanced cancer patients, pelvic bone metastasis often causes pain and gait disturbance. The use of percutaneous bone cement [polymethylmethacrylate (PMMA)] injection for pain management and strengthening in pelvic bone metastasis has rarely been reported. To evaluate this method, we aimed to determine surgical outcomes and complications over a long-term follow-up period using a large patient group. PATIENTS AND METHODS: We retrospectively collected data from 178 patients who underwent percutaneous cementoplasty for pelvic metastatic lesions, 201 in total. Surgical outcomes evaluated included pain reduction and improvement of ambulation. Mortality within 1 month after procedure and pulmonary embolism caused by thrombus, fat, tumor emboli, or bone cement were investigated as surgical complications. For long-term survivors, pain relapse and mechanical failure were analyzed. The mean follow-up period was 12.6 months, and there were 159 fatalities at last follow-up. RESULTS: The mean regional pain numerical rating scale scores decreased from 6.1 preoperatively to 2.4 1 month after procedure (p < 0.01). Gait function was maintained, worsened, and uncheckable in 68%, 24%, and 8% of patients, respectively, 1 month after procedure. Of long-term survivors followed up for > 12 months (n = 53), there were no significant changes in serial plain radiographs, and regional pain aggravation was observed in 9%. Pulmonary cement embolism and bone cement implantation syndrome was observed in 11% and 10%, respectively. However, all patients with these complications were asymptomatic. CONCLUSIONS: Percutaneous cement injection into the pelvis is a feasible and safe palliative surgical option for patients with advanced malignancy in terms of pain reduction and maintenance of ambulatory function under regional anesthesia.

The application of 3D-printing technology in pelvic bone tumor surgery.

BACKGROUND: Three-dimensional (3D)-printing technology provides an advanced approach to pelvic bone tumor resection and reconstruction. However, only a few cases of pelvic bone tumor surgery using 3D-printing have been reported due to limited time since the introduction of the new implant. This study introduces pelvic bone tumor surgeries using 3D-printed bone-cutting guides and implants. METHODS: This single-center retrospective review included 12 patients who underwent malignant pelvic bone tumor surgeries using a 3D-printed bone-cutting guide and/or implant. Clinical information was collected regarding patient demographics, tumor characteristics, pathologic diagnosis, surgery details, and functional recovery. RESULTS: Type I internal hemipelvectomy was performed using 3D-printed bone-cutting guides for 4 patients that underwent cavitary bone tumor resection of the ilium. For 3 of these 4 patients, cavitary bone defects were filled with structural allobone graft precisely trimmed by the 3D-printed allograft-shaping guide (n = 1) and 3D-printed mesh-style titanium spacer (n = 2). For type II and III areas, one and two patients, respectively, underwent 3D-printing-assisted surgery. Five patients underwent type I, II, and III pelvic resection using 3D-printed cutting guides and reconstruction with 3D-printed implants. In all patients, independent gait was recovered except for a patient who underwent hindquarter amputation 4 months postoperatively because of local recurrence. CONCLUSIONS: This study provides preliminary, short-term data on the efficacy and safety of pelvic bone tumor surgery using 3D-printing.

Histologic Response and Toxicity following Interval-Compressed Four-Drug Therapy Given Preoperatively in Children and Young Adults with Osteosarcoma: A Retrospective Study.

OBJECTIVES: The histologic response to chemotherapy is an important prognostic factor in osteosarcoma. Thus, we attempted to develop an effective neoadjuvant regimen to achieve an improvement in histologic response. METHODS: Twenty-nine patients with a high-grade osteosarcoma received 2 courses of neoadjuvant chemotherapy non-randomly with either the MAP regimen (methotrexate 12 g/m2, cisplatin 120 mg/m2, and doxorubicin 75 mg/m2) or MAPI regimen (MAP plus ifosfamide 9 g/m2). We applied interval compression to MAPI by shortening the preoperative period to be aligned with that of MAP. Adjuvant chemotherapy was tailored according to the necrosis rate of resected tumor specimens. Necrosis rate, toxicity, and survival outcome were compared retrospectively between the 2 groups. RESULTS: The median interval between the beginning of neoadjuvant chemotherapy and surgery was 97.0 days in the MAPI group (17 patients) and 90.5 days in the MAP group (12 patients; p = 0.19). The good histologic response (>90% of necrosis) was observed in 71% of MAPI and in 42% of MAP (p = 0.12). Major toxicities of grade 3 or worse were not different between the 2 groups. The probability of 5-year progression-free survival and overall survival of the MAPI group were 74 and 83%, and those in the MAP group were 50 and 75%, showing no difference. CONCLUSIONS: Interval-compressed MAPI therapy given in a similar duration of the preoperative phase to that of conventional MAP therapy showed a marginal trend toward a better histologic response without a significant increase in major toxicities. Regarding the proportion of good histologic response, 71% is one of the highest values ever reported in the literature. The results warrant further testing in a prospective way in a larger cohort.

Preliminary results: use of multi-hole injection nails for intramedullary nailing with simultaneous bone cement injection in long-bone metastasis.

OBJECTIVE: For symptomatic metastasis of the long bones, intramedullary nailing has been the most accepted fixation method. Intramedullary nailing has effective control of pain, perioperative bleeding, and local tumor progression by augmentation with bone cement around the nail. Here, we report the preliminary results of a new surgical implant that allows for simultaneous injection of bone cement while inserting a percutaneous, flexible intramedullary nail. MATERIALS AND METHODS: We performed palliative surgeries for long-bone metastasis using a multi-hole injection nail (MIN) with multiple side holes in the distal one third. When the nail tip entered the metastatic cancer lesion, the bone cement injection was started, and continued until the nail was completely seated. Ten patients with advanced cancer underwent palliative surgery using the new implant with simultaneous bone cement injection for humeral (n = 4), femoral (n = 4), and tibial (n = 2) metastases. RESULTS: The mean operative time was 42 min (range, 36-52 min). The mean length of the injection nail was 23.0 cm (range, 18.0-33.0 cm), and the mean volume of cement was 28.0 ml (range, 14.0-40.0 ml). Marked pain palliation (p < 0.001) and functional recovery (p = 0.01) were verified. The mean Musculoskeletal Tumor Society (MSTS) functional score improved significantly from 12.5 at 6 weeks preoperatively, to 24.9 postoperatively. No acute postoperative complications, including cement embolism, occurred. CONCLUSION: This minimally invasive surgical method with MIN could be useful for stabilization of long-bone metastases in patients with advanced cancer.

Integrated molecular characterization of adult soft tissue sarcoma for therapeutic targets.

BACKGROUND: Several studies have investigated the molecular drivers and therapeutic targets in adult soft tissue sarcomas. However, such studies are limited by the genomic heterogeneity and rarity of sarcomas, particularly in those with complex and unbalanced karyotypes. Additional biomarkers are needed across sarcoma types to improve therapeutic strategies. To investigate the molecular characteristics of complex karyotype sarcomas (CKSs) for therapeutic targets, we performed genomic profiling. RESULTS: The mutational landscape showed that TP53, ATRX, and PTEN genes were highly mutated. CKS samples were categorized into three groups based on copy number variations that were associated with CDK4 and RB1 signatures. Integrated analysis of genomic and transcriptomic data revealed several pathways related to PDGFR, which could be a strategic target for anti-sarcoma therapy. CONCLUSIONS: This study provides a detailed molecular classification of CKSs and proposes several therapeutic targets. Targeted or combinational therapies for treating CKS should be considered before chemotherapy.

Deep learning approach for survival prediction for patients with synovial sarcoma.

Synovial sarcoma is a rare disease with diverse progression characteristics. We developed a novel deep-learning-based prediction algorithm for survival rates of synovial sarcoma patients. The purpose of this study is to evaluate the performance of the proposed prediction model and demonstrate its clinical usage. The study involved 242 patients who were diagnosed with synovial sarcoma in three institutions between March 2001 and February 2013. The patients were randomly divided into a training set (80%) and a testing set (20%). Fivefold cross validation was performed utilizing the training set. The test set was retained for the final testing. A Cox proportional hazard model, simple neural network, and the proposed survival neural network were all trained utilizing the same training set, and fivefold cross validation was performed. The final testing was performed utilizing the isolated test data to determine the best prediction model. The multivariate Cox proportional hazard regression analysis revealed that size, initial metastasis, and margin were independent prognostic factors. In fivefold cross validation, the median value of the receiver-operating characteristic curve (area under the curve) was 0.87 in the survival neural network, which is significantly higher compared to the area under the curve of 0.792 for the simple neural network (p = 0.043). In the final test, survival neural network model showed the better performance (area under the curve: 0.814) compared to the Cox proportional hazard model (area under the curve: 0.629; p = 0.0001). The survival neural network model predicted survival of synovial sarcoma patients more accurately compared to Cox proportional hazard model.

Bone tumor resection guide using three-dimensional printing for limb salvage surgery.

BACKGROUND AND OBJECTIVES: The three-dimensional (3D)-printed bone tumor resection guide can be personalized for a specific patient and utilized for bone tumor surgery. It is noninvasive, eidetic, and easy to use. We aimed to categorize the use of the 3D-printed guide and establish in vivo accuracy data. METHODS: We retrospectively reviewed 12 patients, who underwent limb salvage surgery using the 3D-printed guide at a single institution. To confirm the achievement of a safe bone margin, we compared the actual and planned distances between the cutting surface and tumor, which were reported in the final pathological report and measured from the same virtual cutting plane using graphical data of the cutting guide design, respectively. RESULTS: The use of the 3D-printed guide was categorized as follows: (a) wide excision only, (b) wide excision and biological reconstruction with a structural bone allograft shaped in accordance with the 3D-printed guide, and (c) wide excision and reconstruction with a 3D-printed personalized implant. The maximal cutting error was 3 mm. CONCLUSIONS: The 3D-printed resection guide is easy to use and shows promise in the field of orthopedic oncology, with its application in bone tumor resection and reconstruction with a structural bone allograft or 3D-printed implant.

What Factors Are Associated With Early Mortality in Patients Undergoing Femur Surgery for Metastatic Lung Cancer?

BACKGROUND: Pathologic fractures of the femur resulting from metastasis severely increase mortality in patients with nonsmall cell lung cancer (NSCLC). However, factors associated with early mortality after surgery have not been elucidated. QUESTIONS/PURPOSES: The purpose of this study was to identify clinical and laboratory factors available to surgeons before surgery for a metastatic femur in patients with metastatic lung cancer that might be associated with mortality at 1 and 3 months. METHODS: Between 2010 and 2014 we treated 126 patients for pathologic fracture of the femur caused by NSCLC. Of those, complete data sets for the parameters of interest (including clinical factors, laboratory factors, and survivorship) were available in 105 (83%). The factors we considered included sex, age, fracture location, surgical procedure, postoperative complications, blood cell counts, serum biomarkers, genetic alterations of primary cancer, chemotherapeutic agents, preoperative radiation therapy, pleural effusion, bone and internal organ metastasis, performance scores, and medical center where the treatment was performed. Multivariate logistic regression was performed to identify factors associated with mortality at 1 and 3 months. RESULTS: Intertrochanteric location was associated with a higher risk of death (odds ratio [OR], 17.0; 95% confidence interval [CI], 2.65-109.5), lower serum albumin level was associated with an increased risk of death (OR, 0.13; 95% CI, 0.028-0.60), and availability of a suitable chemotherapeutic target agent was associated with a lower risk of death (OR, 0.28; 95% CI, 0.08-0.91) within 3 months of surgery. Undergoing reconstruction with an endoprosthesis was associated with a higher risk of death (OR, 48.3; 95% CI, 1.7-1329) and elevated serum leukocyte count (OR, 1.2; 95% CI, 1.0-1.4) and elevated alanine aminotransferase (ALT) were associated with a higher risk of death (OR, 1.1; 95% CI, 1.0-1.2) within 1 month of surgery. CONCLUSIONS: Although the risk factors for early mortality need to be validated by prospective studies, surgical options need to be reconsidered in patients with femoral metastases from NSCLS showing high ALT or leukocytosis on the preoperative blood test. LEVEL OF EVIDENCE: Level III, prognostic study.

Joint-preserving palliative surgery using self-locking screws of intramedullary nail and percutaneous cementoplasty for proximal humeral metastasis in the advanced cancer patients.

BACKGROUND: We introduced a palliative joint-preserving surgery using proximal self-locking screws of intramedullary (IM) nail and percutaneous cementoplasty (PC) in patients with proximal humeral metastases, including the head and neck, and evaluated the outcome of the surgical method. METHODS: Twenty-three patients (mean age = 63.0 ± 11.8 years, M:F = 14:9) had IM nailing with a self-locking screw system and PC for the treatment of humeral head and neck metastases. Usually, three proximal locking screws were inserted after IM nailing, and 20.9 ± 8.0 ml of polymethylmethacrylate (PMMA) bone cement was injected in the perimetal osteolytic area. RESULTS: Regional anesthesia with interscalene block was performed in 87.0% (20/23), and the duration of surgery (from anesthesia to awakening) was approximately 40-55 min. Red blood cell was not transfused intra- and/or postoperatively in 65.2% (15/23). The localized preoperative pain (visual analog scale (VAS), 8.2 ± 3.1) was gradually decreased at postoperative 1 week (VAS, 4.9 ± 2.1) and at 6 weeks (VAS, 2.9 ± 2.1) (P < 0.001). Among nine patients who underwent F-18-FDG PET/CT, the proximal humeral metastasis around PC showed improved, stable, and aggravated states in five (55.6%), three (33.3%), and one patient (11.1%), respectively. Meanwhile, 88.8% (8/9) of patients showed aggravation at the naive bone metastasis area. CONCLUSION: The selection of the self-locking screw type of the IM nail and PC was helpful in preventing fixation failure for joint-preserving palliative surgery in the proximal humeral metastasis.

Percutaneous Cementoplasty For Acetabulum In Patients With Bone Metastasis.

The purpose of this study is to demonstrate the surgical technique and to show the results of percutaneous cementoplasty (PC) for acetabular metastases using lateral approach under regional anesthesia. Forty-two cases underwent PC for acetabular metastases. The PC was performed using spinal anesthesia, lateral approach and fluoroscopic guidance. We assessed visual analogue scale (VAS) and revised musculoskeletal tumor society (MSTS) rating system and maximum standardized uptake value (SUVmax) of the acetabular lesion using F-18-FDG PET/CT before and after the PC. The mean injected volume of polymethylmethacrylamide to the pelvis was 21±11.8 ml. The mean of regional VAS (6.2±1.1 vs. 3.1±2.7, p<0.001), MSTS (10.3±3.9 vs. 18.3±3.2, p<0.001) and local SUVmax (8.6±5.2 vs. 5.7±3.6 , p = 0.012) on PET/CT showed significant reductions after surgery. Twenty-three patients (55%) died of disease at mean 11.8±4.8 months after surgery. PC using lateral approach and regional anesthesia could be a simple and safe surgical method for relieving pain and maintaining skeletal stability against acetabular metastasis.

Low-heat treated autograft versus allograft for intercalary reconstruction of malignant bone tumors.

INTRODUCTION: Low-heat treated autograft may have an advantage over allograft in that they provide a size-matched and biologically compatible graft. MATERIALS AND METHODS: We compared the graft survival and complications between the low-heat treated autografts (n = 13) and allografts (17) for intercalary reconstruction of malignant bone tumors. Average age was 25 years with follow-up of 6.6 years (1.8-12.5). For low-heat treatment, the resected bone was treated in saline at 65°C for 30 min. Nineteen grafts were fixed with plates and 13 with intramedullary nails. RESULTS: Until last follow-up, five low-heat treated autografts (38%) and one allograft (6%) had been removed, with allografts showing a trend toward better survival on Kaplan-Meier analysis (P = 0.293). Complications were more common in low-heat treated autograft group [10/13 (77%) vs. 8/17 (47%), P = 0.098)]. Low-heat-treated autograft resulted in significantly higher rate of nonunion [11/26 (42%) vs. 5/34 (15%), P = 0.017] and required higher number of operations to treat nonunion (P = 0.004). Rates of graft fracture [3/13 (23%) vs. 2/17 (12%), P = 0.713)] or infection [2/13 (15%) vs. 1/17 (6%), P = 0.565)] were similar. CONCLUSION: Our data suggest that intercalary allograft has better survival and fewer complications than the low-heat treated autograft.

Whole Blood Titanium Concentration after Limb Salvage Surgery with Three-Dimensional-Printed Ti6Al4V Implants.

Background: Three-dimensional (3D)-printed customized implants can be fabricated and utilized for all bones with massive bone defects. The main safety issues with 3D-printed implants made of Ti6Al4V alloy are related to the release of metal debris and residual powder. In this study, we investigated the perioperative titanium concentrations in whole blood and peri-implant fluid samples of patients who underwent limb salvage surgery with a 3D-printed Ti6Al4V implant. Methods: Nineteen patients who underwent limb salvage surgery with 3D-printed Ti6Al4V implants were divided into two groups: the serial samples group and the follow-up group. To observe metal distribution and clearance in the body, serial samples of blood and peri-implant fluid from the surgical drain were prospectively collected for five patients in the serial samples group. For the remaining 14 patients who were followed up for more than a year, blood samples were collected only once. Results: In the serial samples group, the mean baseline titanium concentration was 0.78 µg/L (range, 0.1-2.2 µg/L): 3 patients showed peak concentration before the third postoperative month, while 2 patients still showed an increasing pattern at this point. Total titanium mass in the surgical drain showed a wash-out phenomenon in a week, with a significant uniform decrease (p = 0.04). In 14 patients in the follow-up group, the mean titanium concentration in the whole blood was 10.8 µg/L (range, 0.3-36.6 µg/L). For the 14 patients with a long-term follow-up, the aluminum and vanadium concentrations were all negligible. Conclusions: Whole blood titanium concentrations were higher after surgery using 3D-printed implants than after that using conventional orthopedic implants, but markedly lower than in patients with implant failure. None of the patients developed serious clinical adverse effects during follow-up.

Sarcoma Immunotherapy: Confronting Present Hurdles and Unveiling Upcoming Opportunities.

Sarcomas are rare and heterogeneous mesenchymal neoplasms originating from the bone or soft tissues, which pose significant treatment challenges. The current standard treatment for sarcomas consists of surgical resection, often combined with chemo- and radiotherapy; however, local recurrence and metastasis remain significant concerns. Although immunotherapy has demonstrated promise in improving long-term survival rates for certain cancers, sarcomas are generally considered to be relatively less immunogenic than other tumors, presenting substantial challenges for effective immunotherapy. In this review, we examine the possible opportunities for sarcoma immunotherapy, noting cancer testis antigens expressed in sarcomas. We then cover the current status of immunotherapies in sarcomas, including progress in cancer vaccines, immune checkpoint inhibitors, and adoptive cellular therapy and their potential in combating these tumors. Furthermore, we discuss the limitations of immunotherapies in sarcomas, including a low tumor mutation burden and immunosuppressive tumor microenvironment, and explore potential strategies to tackle the immunosuppressive barriers in therapeutic interventions, shedding light on the development of effective and personalized treatments for sarcomas. Overall, this review provides a comprehensive overview of the current status and potential of immunotherapies in sarcoma treatment, highlighting the challenges and opportunities for developing effective therapies to improve the outcomes of patients with these rare malignancies.

New established cell lines from undifferentiated pleomorphic sarcoma for in vivo study.

As a high-grade soft-tissue sarcoma (STS), undifferentiated pleomorphic sarcoma (UPS) is highly recurrent and malignant. UPS is categorized as a tumor of uncertain differentiation and has few options for treatment due to its lack of targetable genetic alterations. There are also few cell lines that provide a representative model for UPS, leading to a dearth of experimental research. Here, we established and characterized new cell lines derived from two recurrent UPS tissues. Cells were obtained from UPS tissues by mincing, followed by extraction or dissociation using enzymes and culture in a standard culture environment. Cells were maintained for several months without artificial treatment, and some cell clones were found to be tumorigenic in an immunodeficient mouse model. Interestingly, some cells formed tumors in vivo when injected after aggregation in a non-adherent culture system for 24 h. The tissues from in vivo study and tissues from patients shared common histological characteristics. Pathways related to the cell cycle, such as DNA replication, were enriched in both cell clones. Pathways related to cell-cell adhesion and cell-cell signaling were also enriched, suggesting a role of the mesenchymal-to-epithelial transition for tumorigenicity in vivo. These new UPS cell lines may facilitate research to identify therapeutic strategies for UPS. [BMB Reports 2023; 56(4): 258-264].

Clinical characteristics and long-term outcomes of rhabdomyosarcoma in Korean children, adolescents and young adults: a single-center experience.

PURPOSE: This study aimed to analyze characteristics, treatment, long-term outcomes, and prognostic factors for children, adolescents and young adults with rhabdomysosarcoma (RMS). METHODS: This retrospective historical study included 75 patients with RMS treated between 2002 and 2019. Clinical data and follow-up results were collected including all diagnosis, treatment and prognosis information. RESULTS: Patients median-age-at-diagnosis was 6 years. Embryonal and alveolar histology occurred in 51 (68.0%) and 21 (28.0%) patients, respectively. The tumors most frequently originated from parameningeal site (28.0%). Of 74 evaluable patients for treatment outcome, 60 (81.1%) achieved complete response for first-line treatment, of whom, 34 (56.6%) maintained complete response, 26 (43.3%; 23/26, local relapse) showed relapse. Of 40 patients with treatment failure, 16 and 6 occurred in parameningeal area and retroperitoneum/perineum, respectively. The 5-year progression-free survival (PFS) and overall survival (OS) were 45.0% and 64.5%, respectively. In multivariate analyses, parameningeal site (p = 0.027), no gross total resection (p = 0.047), and no radiation therapy (RT) (p < 0.001) for PFS; and parameningeal site (p < 0.001) and no RT (p = 0.010) for worse OS, were significant. The median PFS and OS from treatment failure date in 40 patients with primary treatment failure were 1.3 and 4.1 years, respectively. Of 26 patients with relapse, interval to relapse < 7 months, retroperitoneum/perineum site, TNM stages III/IIV, and no salvage RT were independently associated with OS. CONCLUSION: The importance of adequate local therapy was highlighted in RMS treatment. Treatment failure was largely a local failure. Whether as a component of initial or salvage treatment, RT could improve patients' survival.

Prediction of tumour necrosis fractions using metabolic and volumetric 18F-FDG PET/CT indices, after one course and at the completion of neoadjuvant chemotherapy, in children and young adults with osteosarcoma.

PURPOSE: The utility of combined metabolic and volumetric (18)F-FDG PET/CT indices for predicting tumour necrosis fractions following neoadjuvant chemotherapy has not been extensively studied in osteosarcoma. Furthermore, little is known of the early PET/CT responses after only one chemotherapy course. METHODS: Enrolled in the study were 20 children and young adults with resectable osteosarcoma who had undergone (18)F-FDG PET/CT scans before and after neoadjuvant chemotherapy. Maximum standardized uptake value (mSUV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured. From among the 20 patients, 14 were prospectively recruited and underwent an additional PET/CT scan after one chemotherapy course. Histopathological necrosis fractions were compared with the above-mentioned PET/CT indices and their ratios. RESULTS: MTV at the SUV threshold of 2 g/ml was closely correlated with the magnetic resonance image volumes before therapy (r = 0.91). In the prospective cohort, five patients were classified as good responders and nine as poor responders. All the metabolic indices (mSUV and its ratio) and combined metabolic/volumetric indices (MTV, TLG, and their ratios) except the mSUV ratio determined after therapy showed significant differences between good and poor responders (P <0.05). Differences were also noted for all of these indices determined after one chemotherapy course. Furthermore, most of these indices determined after therapy as well as after one chemotherapy course had good sensitivity, specificity, positive predictive value and negative predictive value with respect to predicting histological response to chemotherapy. CONCLUSION: In our osteosarcoma patient population, (18)F-FDG PET/CT indices (either combined metabolic/volumetric or metabolic indices) determined after neoadjuvant chemotherapy were useful in predicting tumour responses. This held true after only one chemotherapy course.

Clinical features of partial anterior bursal-sided supraspinatus tendon (PABST) lesions.

BACKGROUND: We characterized partial anterior and bursal supraspinatus tendon (PABST) lesions and compared their clinical features, postoperative functional scores, and healing rate with full-thickness rotator cuff tears (FTRCTs) and small FTRCTs. MATERIALS AND METHODS: There were 31 PABST lesions (6.2%), 392 FTRCTs, and 32 small FTRCTs among 495 shoulders with rotator cuff disorders. The mean patient age was 52.7 years in the PABST group, 60.1 years in the FTRCT group, and 56.9 years in the small FTRCT group. Functional and clinical variables were compared between the groups, and cuff healing was evaluated with computed tomography arthrography or ultrasonography. RESULTS: The mean patient age was statistically lower, the mean symptom duration was shorter, and trauma was more frequent in the PABST group compared with the FTRCT and small FTRCT groups. Coronal acromial spurs were found more frequently in the PABST group than in the FTRCT group. In all groups, range of motion, visual analog scale for pain, and functional scores improved continuously throughout the follow-up. There were 2 unhealed cuffs (10.5%) in the PABST group, 72 (35.6%) in the FTRCT group (P = .146), and 5 (25%) in the small FTRCT group (P = .238). CONCLUSIONS: We characterized PABST lesions that may be overlooked because of their peculiar location in the far anterolateral insertional section of the supraspinatus tendon at the bursal side. PABST lesions usually occur in younger patients, and trauma is frequently associated with acute symptom onset. Surgical treatment was effective for pain reduction and functional improvement.

Evaluation of Intraosseous Pressure during Pelvic Percutaneous Cement Injection: An In Vitro Study in Swine.

Background: A minimally invasive procedure for symptomatic pelvic bone metastasis is a feasible option for advanced cancer patients, and bone cement injection plays an essential role. Pulmonary embolism caused by thrombus, fat, or tumor emboli is a major complication related to bone cement injection, and increasing intraosseous pressure is a predisposing factor. This study aimed to quantify the degree of pressure change in the pelvic bone during percutaneous bone cement injection and investigate whether there is a significant decrease in intraosseous pressure when a decompressive route is additionally established. Methods: Bone cement injection into the acetabulum of swine pelvises by simulating the actual surgical procedure in terms of the injection method, bone cement, and surgical instruments was performed while recording the intraosseous pressure. Twenty swine pelvises were used and grouped into a decompression group and a non-decompression group. Bone cement injection and pressure measurement were conducted in the same way in both groups, but an additional decompressive route was established for each pelvis in the decompression group. Continuous variables were compared using the Mann-Whitney test. Results: The mean amount of injected bone cement was 19.8 mL and 20.3 mL and the mean speed of bone cement injection was 0.14 mL/sec and 0.12 mL/sec in the decompression group and the non-decompression group, respectively. The mean peak intraosseous pressures was 10.5 kPa with decompression and 37.8 kPa without decompression, and the difference was statistically significant (p < 0.01). Conclusions: Intraosseous pressure during bone cement injection into swine pelvises was similar to that during vertebroplasty or kyphoplasty. When the additional decompression route was established, the intraosseous pressure decreased to one third the level.