Embryonal and alveolar rhabdomyosarcoma in adolescents/young adults, adults and older adults: a population-based cohort study.

BACKGROUND: The clinical characteristics, outcomes, and prognostic factors of adult embryonal rhabdomyosarcomas (ERMS) and alveolar rhabdomyosarcomas (ARMS), particularly the differences among adolescents/young adults (AYA), adults, and older adults, remain unclear. We assessed the clinicopathological features and survival outcomes of adult patients with ERMS and ARMS in Japan and to compare these features among AYA, adult, and older adult patients. METHODS: We retrospectively analyzed data from the Bone and Soft Tissue Tumor Registry of Japan and enrolled patients aged ≥15 years with ERMS and ARMS. Disease-specific overall survival (DOS) was estimated using the Kaplan-Meier method, and a Cox regression model was used to identify prognostic factors. RESULTS: Among 184 patients with ERMS and ARMS (median age, 27 years; interquartile range, 18-49 years), a high rate of distant and regional nodal metastases was initially observed in 65 (35%) and 66 (36%) cases, respectively. Older age and distant metastasis at first presentation were statistically poor prognostic factors, and histological subtype and site of tumor origin were not associated with DOS. In patients with localized ERMS and ARMS, older age and nodal metastasis were poor prognostic factors; the 5-year DOS rates of patients with and without nodal metastasis were 23% and 72%, respectively. CONCLUSIONS: Older patients with rhabdomyosarcoma had a dismal prognosis, and distant metastasis was a poor prognostic factor. The prognostic factors differed between adult and pediatric patients with rhabdomyosarcoma; biological analyses, such as genome analysis of adult rhabdomyosarcoma and clinical trials with pediatric oncologists, are needed to improve the prognosis of adult rhabdomyosarcoma.

Clinical genomic profiling of malignant giant cell tumor of bone: A retrospective analysis using a real­world database.

Malignant giant cell tumor of bone (GCTB) is identified by the presence of multinucleated giant cells, with an aggressive behavior and a high risk of metastasis, which has not been genetically characterized in detail. H3 histone family member 3A (H3F3A) gene mutations are highly recurrent and specific in GCTB. The present study analyzed the clinical information and genomic sequencing data of eight cases of malignant GCTB (out of 384 bone sarcoma samples) using an anonymized genomic database. There were 5 males and 3 females among the cases, with a median age of 33 years at the time of the initial diagnosis. H3F3A G34W and G34L mutations were detected in 3 patients and 1 patient, respectively. In 75% of cases without H3F3A mutation, mitogen-activated protein kinase (MAPK) signaling pathway gene alterations were found (KRAS single nucleotide variant, KRAS amplification, nuclear respiratory factor 1-BRAF fusion). Moreover, the collagen type I alpha 2 chain-ALK fusion was detected in remaining one case. The most frequent gene alterations were related to cell cycle regulators, including TP53, RB1, cyclin-dependent kinase inhibitor 2A/B and cyclin E1 (75%, 6 of 8 cases). On the whole, the present study discovered recurrent MAPK signaling gene alterations or other gene alterations in cases of malignant GCTB. Of note, two fusion genes should be carefully validated following the pathology re-review by sarcoma pathologists. These two fusion genes may be detected in resembling tumors, which contain giant cells, apart from malignant GCTB. The real-world data used herein provide a unique perspective on genomic alterations in clinicopathologically diagnosed malignant GCTB.

Prognostic factors and treatment outcomes in patients with pleomorphic rhabdomyosarcoma: a population-based cohort study.

BACKGROUND: Pleomorphic rhabdomyosarcoma is a rare sarcoma in adults. The clinical characteristics, outcomes and prognostic factors associated with pleomorphic rhabdomyosarcoma remain unclear. METHODS: We retrospectively analyzed data from the Bone and Soft Tissue Tumor Registry of Japan, and enrolled patients with pleomorphic rhabdomyosarcoma. Disease-specific overall survival, local recurrence-free survival and distant metastasis-free survival were estimated using the Kaplan-Meier method; Cox regression model was used to identify prognostic factors. RESULTS: In total, 182 patients with pleomorphic rhabdomyosarcoma were included. Median age was 63 (range 20-95) years. The lower extremity (48%) was the most frequent tumor origin site, while head and neck were rare (4%). A total of 43 patients (24%) had distant or regional nodal metastases at first presentation. In all cases, the 2-year and 5-year survival rates were 66.3% and 54.1%, respectively. Distant metastasis was a significant poor prognostic factor (Hazard ratio 6.65; 95% confidence intervals, 3.00-14.75, P < 0.0001), with median survival of such patients being 9.4 (95% confidence intervals: 5.3-12.2) months. In 134 localized cases, the 2-year and 5-year survival rates were 91.5% and 68.3%, respectively. Large tumor size and older age were associated with poorer prognosis. Through data from localized and locally curative cases extracted and adjusted by propensity score matching, we found that perioperative chemotherapy did not improve disease-specific overall survival, distant metastasis-free survival or local recurrence-free survival. CONCLUSIONS: Clinical characteristics and outcomes of pleomorphic rhabdomyosarcoma are similar to those of other high-grade soft tissue sarcomas. Pleomorphic rhabdomyosarcoma may be less chemosensitive, and a strategy other than the standard cytotoxic chemotherapy is required to improve its prognosis.

Extended curettage for tumour-induced osteomalacia in the bone.

BACKGROUND: extended curettage is generally used to treat infiltrative bone tumours. However, the extent of the curettage performed in previous studies remains unclear. This study aimed to investigate the efficacy of extended curettage for bone tumour-induced osteomalacia. METHODS: we included 12 patients with tumour-induced osteomalacia who underwent extended curettage at our hospital between 2000 and 2022. Extended curettage was applied in cases where tumour resection could cause functional impairment or necessitate complex reconstruction. We investigated patients' clinical and oncological outcomes. RESULTS: patients had a mean age of 55 (24-81) years, and the median follow-up duration after surgery was 3.9 (1.0-14.0) years. The causative tumours were located in the pelvis and lumbar spine. Imaging revealed the tumours to be of the sclerotic, intertrabecular, lytic and mixed types. Intraoperative 3D fluoroscopy was used in 10 patients. Extended curettage with high-speed burring and adjuvant therapy with cauterization using an electric scalpel and ethanol resulted in a remission rate of 83%; no recurrence or metastasis was observed in cases of early postoperative biochemical remission. In cases where the causative tumour was at the lumbar spine and ischium close to the acetabulum, no postoperative biochemical remission was observed, and conservative treatment was continued. Except for one patient with a tumour in the lumbar spine, all patients could walk without a cane. CONCLUSIONS: extended curettage for bone tumour-induced osteomalacia is oncologically and functionally favourable, especially in cases where resection of the causative tumour could cause functional impairment or necessitate complex reconstruction.

BRAF mutations and concurrent alterations in patients with soft tissue sarcoma.

BRAF alterations, including V600E and non-V600E mutations and fusions, in soft tissue sarcoma (STS) have been identified in a limited case series. Here, we aimed to evaluate the frequency of BRAF mutations and concurrent alterations in STS to understand their therapeutic action. In this retrospective analysis, we included data from 1964 patients with advanced STS who underwent comprehensive genomic profiling tests at hospitals in Japan between June 2019 and March 2023. The prevalence of BRAF and recurrent concurrent gene alterations were also investigated. BRAF mutations were detected in 24 (1.2%) of 1964 STS patients, with a median age of 47 (range 1-69) years. BRAF V600E was detected in 11 (0.6%) of the 1964 patients with STS, BRAF non-V600E mutations in 9 (4.6%), and BRAF fusions were detected in 4 (0.2%). BRAF V600E was identified in 4 (0.2%) cases of malignant peripheral nerve sheath tumors. The most common concurrent alteration was CDKN2A (11 cases, 45.8%), and the frequency was equivalent to that of the BRAF V600E (5/11 cases, 45.5%) and non-V600E (5/9 cases, 55.6%) groups. Recurrent concurrent alterations, such as TERT promoter mutations (7 cases, 29.2%), were detected at the same frequency in the V600E and non-V600E groups. In contrast, TP53 alterations (4/9 cases, 44.4%) and mitogen-activated protein kinase (MAPK)-activating genes, including NF1, GNAQ, and GNA11 (3/9 cases, 33.3%), were identified as relatively higher in the non-V600E group than in the V600E group (each 1/11 case, 9.1%). We identified BRAF alterations at a rate of 1.2% in all patients with advanced STS. Among them, BRAF V600E and BRAF fusions account for 45.8% and 16.7%, respectively. Collectively, our findings support the clinical characteristics and therapeutic strategies for patients with BRAF-altered advanced STS.

Patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia.

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition. The study included 33 patients with TIO who were treated between January 2000 and June 2022. The causative tumour was detected in all patients. We investigated the symptoms and evaluated the radiological patterns of insufficiency fractures of the rib, spine, and limbs. The mean age of the patients was 57 years (24 to 87), and the mean duration of pain from onset to time of presentation was 3.9 years (0.75 to 23). The primary symptoms were low back pain (ten patients), chest wall pain (eight patients), and hip pain (eight patients). There were symptoms at more sites at the time of presentation compared with that at the time of the onset of symptoms. Bone scans showed the uptake of tracer in the rib (100%), thoracic and lumbar vertebrae (83%), proximal femur (62%), distal femur (66%), and proximal tibia (72%). Plain radiographs or MRI scans identified femoral neck fractures in 14 patients, subchondral insufficiency fractures of the femoral head and knee in ten and six patients, respectively, distal femoral fractures in nine patients, and proximal tibial fractures in 12 patients. Thoracic or lumbar vertebral fractures were identified in 23 of 29 patients (79.3%) when using any imaging study, and a biconcave deformity was the most common type of fracture. Insufficiency fractures in patients with TIO caused spinal pain, chest wall pain, and periarticular pain in the lower limbs. Vertebral fractures tended to be biconcave deformities, and periarticular fractures of the hips and knees included subchondral insufficiency fractures and epiphyseal or metaphyseal fractures. In patients with a tumour, the presence of one or more of these symptoms and an insufficiency fracture should suggest the diagnosis of TIO.

Generating in vitro models of NTRK-fusion mesenchymal neoplasia as tools for investigating kinase oncogenic activation and response to targeted therapy.

The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as pan-tumor oncogenic drivers has led to new personalized therapies in oncology. Recent studies investigating NTRK fusions among mesenchymal neoplasms have identified several emerging soft tissue tumor entities displaying various phenotypes and clinical behaviors. Among them, tumors resembling lipofibromatosis or malignant peripheral nerve sheath tumors often harbor intra-chromosomal NTRK1 rearrangements, while most infantile fibrosarcomas are characterized by canonical ETV6::NTRK3 fusions. However, appropriate cellular models to investigate mechanisms of how kinase oncogenic activation through gene fusions drives such a wide spectrum of morphology and malignancy are lacking. Progress in genome editing has facilitated the efficient generation of chromosomal translocations in isogenic cell lines. In this study we employ various strategies to model NTRK fusions, including LMNA::NTRK1 (interstitial deletion) and ETV6::NTRK3 (reciprocal translocation) in human embryonic stem (hES) cells and mesenchymal progenitors (hES-MP). Here, we undertake various methods to model non-reciprocal, intrachromosomal deletions/translocations by induction of DNA double strand breaks (DSBs) exploiting either the repair mechanisms of homology directed repair (HDR) or non-homologous end joining (NHEJ). Expression of LMNA::NTRK1 or ETV6::NTRK3 fusions in either hES cells or hES-MP did not affect cell proliferation. However, the level of mRNA expression of the fusion transcripts was significantly upregulated in hES-MP, and phosphorylation of the LMNA::NTRK1 fusion oncoprotein was noted only in hES-MP but not in hES cells. Similarly, an NTRK1-driven transcriptional profile related to neuronal and neuroectodermal lineage was upregulated mainly in hES-MP, supporting the importance of appropriate cellular context in modeling cancer relevant aberrations. As proof of concept of the validity of our in vitro models, phosphorylation was depleted by two TRK inhibitors, Entrectinib and Larotrectinib, currently used as targeted therapy for tumors with NTRK fusions.

Clinical analysis of multimodal treatment for localized synovial sarcoma: A multicenter retrospective study.

INTRODUCTION: Several prognostic factors for survival in synovial sarcoma have been proposed, but the role of adjuvant chemotherapy and radiotherapy is a matter of debate. The study aim was to clarify the effect of high-dose ifosfamide-containing chemotherapy and adjuvant radiotherapy for patients with localized synovial sarcoma. MATERIALS AND METHODS: Five tertiary musculoskeletal oncology hospitals participated in this retrospective study. The records of the patient diagnosed with synovial sarcoma without metastasis at diagnosis from 1990 to 2011 have been collected and reviewed. Overall, distant failure-free, and local failure-free survivals were calculated, and prognostic factors for each survival were evaluated by performing univariate and multivariate analyses. RESULTS: A total of 162 patients were enrolled in this study with a median follow-up period of 67 months (range, 5-267 months) for all surviving patients. The 5-year overall, distant failure-free, and local failure-free survival rates were 79.7%, 66.3%, and 98.4%, respectively. Univariate analyses demonstrated that high-dose ifosfamide-containing chemotherapy was significantly associated with better overall (p = 0.014) and distant failure-free survival (p = 0.0043) than that of low-dose or no ifosfamide-containing chemotherapy if we analyzed only patients with tumors >5 cm in size. Addition of radiotherapy was not a significant prognostic factor for overall survival in the univariate and multivariate analyses, but it did improve the overall survival of the patients with R1 resection (p = 0.053). CONCLUSION: Patients with localized synovial sarcoma >5 cm in size had better overall and distant failure-free survival after receiving adjuvant chemotherapy containing high-dose ifosfamide comparing to low-dose or no ifosfamide-containing chemotherapy. The addition of adjuvant radiotherapy was beneficial for the patients who received R1 resection. Alternatively, adjuvant radiotherapy could be avoided for patients who achieved an R0 margin.

Role of perioperative chemotherapy and radiotherapy for localized high-grade malignant peripheral nerve sheath tumor at the extremities and trunk wall: a population-based cohort study.

BACKGROUND: Primary tumor resection is the mainstay of treatment for malignant peripheral nerve sheath tumors. However, the efficacy of perioperative chemotherapy and radiotherapy for malignant peripheral nerve sheath tumors has not been elucidated. METHODS: This retrospective analysis based on a Japanese registry included patients with localized malignant peripheral nerve sheath tumors arising at the extremities and trunk wall. Disease-specific overall survival and local recurrence-free survival were estimated using the Kaplan-Meier method. A Cox regression model was used to identify prognostic factors. Characteristics of groups with or without chemotherapy were adjusted using propensity score matching. RESULTS: In total, 291 patients were included. The 5-year disease-specific overall survival rate was 70.6%. Multivariate analysis of disease-specific overall survival revealed that deep-seated tumors were a poor prognostic factor, but perioperative chemotherapy was not associated with disease-specific overall survival (hazard ratio, 0.81; 95% confidence interval, 0.45-1.43, P = 0.46). Local recurrence was observed in 55 patients (19.0%), and surgical margins (R1 and R2) were significant risk factors. Overall, perioperative chemotherapy did not prolong disease-specific overall survival (5-year disease-specific overall survival: 74.1% vs. 69.3%, P = 0.75) and had limited efficacy in the group with tumor size ≥ 5 cm, although the difference was not statistically significant (5-year disease-specific overall survival: 77.2% vs. 68.6%, respectively, P = 0.13). After adjustment by propensity score matching, perioperative chemotherapy significantly prolonged disease-specific overall survival (5-year disease-specific overall survival: 74.9% vs. 57.1%, P = 0.03), but this effect was not observed in local recurrence-free survival. In all patients, perioperative radiotherapy did not correlate with local recurrence-free survival (hazard ratio, 1.43; 95% confidence interval 0.78-2.62, P = 0.25). CONCLUSIONS: Perioperative chemotherapy had limited efficacy for disease-specific overall survival in patients with localized malignant peripheral nerve sheath tumors.

Dramatic response to entrectinib in a patient with malignant peripheral nerve sheath tumor harboring novel SNRNP70-NTRK3 fusion gene.

Neurotropic tropomyosin receptor kinase (NTRK) gene rearrangements have been reported in limited cases of sarcomas; however, to date, there has been only one report of such rearrangements in malignant peripheral nerve sheath tumors (MPNSTs). Herein, we describe a 51-year-old male patient with a buttock tumor arising from the sciatic nerve, which was diagnosed as MPNST with positive S-100 staining, negative SOX10 staining, and loss of trimethylation at lysine 27 of histone H3 (H3K27me3) confirmed by immunohistochemistry. Soon after the resection of the primary tumor, the patient was found to have pulmonary and lymph node metastases. Chemotherapy with eribulin and trabectedin showed limited effects. However, the patient responded rapidly to pazopanib, but severe side effects caused discontinuation of the treatment. RNA panel testing revealed a novel fusion gene between Small Nuclear Ribonucleoprotein U1 Subunit 70 (SNRNP70) gene and NTRK3 gene. Furthermore, loss of NF1, SUZ12, and CDKN2A genes was confirmed by DNA panel testing, which is compatible with a histological diagnosis of MPNST. SNRNP70 possesses a coiled-coiled domain and seems to induce constitutive activation of NTRK3 through dimerization. In fact, immunohistochemistry revealed diffuse staining of pan-TRK within tumor cells. Treatment with entrectinib, which is an NTRK inhibitor, showed a quick and durable response for 10 months. Although NTRK rearrangements are very rare in MPNST, this case highlights the importance of genetic testing in MPNST, especially using an RNA panel for the detection of rare fusion genes.

Preoperative arterial embolization and wound complications after resection of malignant bone tumor in the pelvis: a nationwide database study.

BACKGROUND: Massive intraoperative blood loss is common in pelvic malignant bone tumor surgery, and preoperative arterial embolization may be used in selected cases. Preoperative arterial embolization reportedly increases wound complications in pelvic fracture surgery, but little evidence is available regarding pelvic bone tumor surgery. METHODS: Using a Japanese nationwide database (Diagnosis Procedure Combination database), we searched for patients who underwent pelvic malignant bone tumor surgery between July 2010 and March 2018. The primary endpoint was wound complications, defined as any wound requiring re-operation, negative pressure wound therapy or both. Univariate analyses (the chi-squared test for categorical variables, the unpaired t-test for continuous variables) and multivariate logistic regression analyses were performed to examine the association between preoperative arterial embolization and wound complications. RESULTS: Among the 266 eligible patients, 43 (16%, 43/266) underwent embolization and 69 (26%, 69/266) developed wound complications. In the univariate analyses, preoperative arterial embolization (P < 0.001), duration of anesthesia (P < 0.001), the volume of blood transfusion (P < 0.001) and duration of indwelling drain tube (P < 0.001) were associated with wound complications. In the multivariate logistic regression analysis, preoperative arterial embolization was significantly associated with wound complications (odds ratio, 3.92; 95% confidence interval, 1.80-8.56; P = 0.001). CONCLUSIONS: Preoperative arterial embolization may be associated with increased wound complications after pelvic malignant tumor surgery.

Clinical characteristics of undifferentiated pleomorphic sarcoma of bone and the impact of adjuvant chemotherapy on the affected patients: a population-based cohort study.

BACKGROUND: Clinical characteristics of undifferentiated pleomorphic sarcoma of bone are not elucidated. Herein, we clarify its clinical features and analyze the efficacy of adjuvant chemotherapy in patients with undifferentiated pleomorphic sarcoma of bone. METHODS: Prognostic factors and estimated disease-specific survival in 247 patients with primary undifferentiated pleomorphic sarcoma of bone were identified from a registry in Japan. The effect of adjuvant chemotherapy was evaluated in localized resectable cases, and the characteristics of the two groups treated with or without chemotherapy were adjusted using propensity score matching. RESULTS: The 5-year disease-specific survival rates were 47.4% in the entire cohort and 56.4 and 16.9% in the M0 and M1 groups, respectively. Multivariate disease-specific survival analysis revealed that metastasis on initial presentation and age ≥ 65 years were poor prognostic factors. Overall, 132 localized and resectable primary lesions were extracted. Adjuvant chemotherapy administration was a favorable prognostic factor (hazard ratio: 0.43, P = 0.04), and it significantly prolonged disease-specific survival compared with no adjuvant chemotherapy (5-year disease-specific survival: 78.8% vs. 51.8%, P = 0.008). Adjuvant chemotherapy prolonged disease-specific survival in patients with tumor size <8 cm (5-year disease-specific survival: 100% vs. 54.6%, P = 0.02); however, its efficacy decreased in those with tumor size ≥8 cm (5-year disease-specific survival: 68.7% vs. 42%, P = 0.09). After propensity score matching, adjuvant chemotherapy was significantly associated with good disease-specific survival (P = 0.02). CONCLUSIONS: Metastasis in the initial presentation was the poorest prognostic factor. On evaluating localized and resectable cases only, adjuvant chemotherapy significantly improved disease-specific survival, although its effect decreased in cases with large tumors.

Role of adjuvant chemotherapy in patients with localized, undifferentiated pleomorphic sarcoma of soft tissue: a population-based cohort study.

BACKGROUND: Primary tumor resection is the mainstay of treatment for undifferentiated pleomorphic sarcoma (UPS); however, the necessity of adjuvant chemotherapy has been debated. We aimed to clarify the effect of adjuvant chemotherapy on survival rates in patients with UPS with localized and resectable primary lesions. METHODS: This retrospective analysis included data of 2112 patients with localized UPS arising in the extremities and trunk, extracted from a registry in Japan. We estimated overall survival (OS), identified prognostic factors, and adjusted patient characteristics in the two groups treated with or without chemotherapy using propensity score matching (PSM). RESULTS: The 5-year OS rate was 79.4%. In multivariate OS analysis, adjuvant chemotherapy was a good prognostic factor (hazard ratio 0.65; 95% confidence interval 0.48-0.9, P = 0.009). Large tumor size was the poorest prognostic factor, and OS decreased with the tumor size (P < 0.0001). In all patients, adjuvant chemotherapy prolonged OS (5-year OS: 82.3% vs. 78.6%, P = 0.03). Adjuvant chemotherapy did not affect OS in patients with tumor size < 5 cm; the benefit was strong in patients with tumor size 10 to < 15 cm (5-year OS: 79.5% vs. 66.8%, P = 0.003). Adjuvant chemotherapy efficacy was not pronounced in patients with tumor size 5 to < 10 cm (5-year OS: 87% vs. 80%, P = 0.06) and ≥ 15 cm (5-year OS: 60.7% vs. 49.5%, P = 0.08). After PSM, adjuvant chemotherapy was significantly associated with improved OS (P = 0.02). CONCLUSIONS: In patients with localized UPS, adjuvant chemotherapy tended to improve OS when tumors were ≥ 5 cm, especially when they were 10 to < 15 cm.

Impact of the national sarcoma guidelines on the prevalence and outcome of inadvertent excisions of soft tissue sarcomas: An observational study from a UK tertiary referral centre.

OBJECTIVES: This study aims to investigate the impact of the national guideline on the prevalence and outcome in patients with soft-tissue sarcoma (STS) who had undergone inadvertent excisions. METHODS: A total of 2336 patients were referred to a tertiary sarcoma centre from six regions (North East, North West, East Midlands, West Midlands, Wales, and South West) in the United Kingdom with a diagnosis of STS between 1996 and 2016, of whom 561 patients (24.0%) had undergone inadvertent excisions. Patients were categorised into two groups of 10-year periods pre and post the National Institute for Health and Clinical Excellence (NICE) guideline implementation in 2006. RESULTS: The proportion of inadvertent excisions decreased after the NICE guideline implementation: 27.2% (pre-NICE) versus 19.8% (post-NICE) (p = 0.001). A substantial regional variation (17.4%-34.5%) in the proportion of inadvertent excisions in the pre-NICE era was reduced in the post-NICE era (14.3%-22.4%). The 5-year disease-specific survival was 77.7% (pre-NICE) versus 75.6% (post-NICE) (p = 0.961) and there was a trend toward lower incidence of local recurrence in the post-NICE era; 13.5% (pre-NICE) versus 10.5% (post-NICE) (p = 0.522). Multivariate analyses revealed that residual tumours in re-resection specimens were independently associated with an increased risk of disease-specific mortality (HR, 3.35; p < 0.001) and local recurrence (HR, 1.99; p = 0.017), which was significantly reduced after the NICE guideline implementation (53.2% versus 42.0%; p = 0.022). CONCLUSIONS: The NICE guideline implementation reduced the proportion of patients with STS who had undergone inadvertent excisions and residual tumour in re-resection specimens, indicating an improved pre-referral management of STSs.

Comparison of clinical features and outcomes of patients with leiomyosarcoma of bone and soft tissue: a population-based cohort study.

BACKGROUND: Leiomyosarcoma commonly occurs in soft tissue but rarely in the bone. Whether leiomyosarcoma of bone and soft tissue have similar clinical characteristics and outcomes remains unknown. METHODS: This retrospective analysis was based on data from the Bone and Soft Tissue Tumor Registry in Japan. Patients with leiomyosarcoma of bone and soft tissue were enrolled. Overall survival and distant metastasis-free survival were estimated using the Kaplan-Meier method, and the Cox regression model was used to identify the prognostic factors. RESULTS: A total of 888 patients (60 leiomyosarcoma of bone and 828 leiomyosarcoma of soft tissue) were included in the study. Clinical characteristics were similar between the two groups, except for younger age in leiomyosarcoma of bone than in leiomyosarcoma of soft tissue (median 56 years vs. 66 years, P < 0.0001). To evaluate the prognostic factors and efficacy of adjuvant chemotherapy, data of localized and locally curative cases were extracted (total 572: 33 leiomyosarcoma of bone and 539 leiomyosarcoma of soft tissue). The 5-year overall survival rates of leiomyosarcoma of bone and soft tissue patients were similar (63.8% vs. 75.2%, P = 0.43); the 5-year distant metastasis-free survival tended to be worse in leiomyosarcoma of bone than in leiomyosarcoma of soft tissue (37.4% vs. 57.9%, P = 0.28). Larger tumor size (≥5 cm) and older age (≥65 years) correlated with poor overall survival in leiomyosarcoma of soft tissue patients. Adjuvant chemotherapy tended to prolong the overall survival of both leiomyosarcoma of bone (P = 0.11) and leiomyosarcoma of soft tissue patients with tumor size >10 cm (P = 0.06). CONCLUSIONS: The clinical characteristics and outcomes of leiomyosarcoma of bone and soft tissue patients were similar. In localized cases, adjuvant chemotherapy may improve the survival of leiomyosarcoma of bone and soft tissue patients with large-size tumor.

Atypical Neurofibromatous Neoplasm with Uncertain Biologic Potential in the Posterior Mediastinum of a Young Patient with Neurofibromatosis Type 1: A Case Report.

Atypical neurofibromatous neoplasm with unknown biological potential (ANNUBP), proposed in a recent NIH consensus overview, is a rare precursor entity of malignant peripheral nerve sheath tumor (MPNST) in neurofibromatosis type 1 (NF1) patients. Only one report on imaging findings of ANNUBP is available. Herein, we present the case of a 19-year-old female, diagnosed with a mediastinal tumor by chance, who visited to our hospital. She had café-au-lait spots on her trunk and a past history of resected neurofibroma. Her family also had café-au-lait spots; therefore, an NF1-induced tumor was strongly suspected. MRI revealed a paravertebral mass of 7.5 cm in size consisting of an inner rim with low T2 signal intensity and an outer rim with high T2 intensity, which was similar to a target sign, adjacent to the pulmonary veins; the center of the tumor was well enhanced by gadolinium, and the peripheral region was myxoid and slightly enhanced. FDG-PET showed high FDG uptake, SUVmax of 8.5, although the peripheral region represented low FDG accumulation. CT-guided needle biopsy was repeated because of the suspicion of an MPNST, which resulted in the histopathological diagnosis of ANNUBP. Marginal tumor resection was performed, and the final post-resection histopathological diagnosis was ANNUBP transformed from neurofibroma; the region of ANNUBP lost p16 immunostaining, although it was retained in the peripheral region of the neurofibroma. There has been no recurrence or metastasis 1 year after treatment. In conclusion, ANNUBP could be represented as a well-enhanced homogeneous mass on MRI and a high FDG accumulated region on FDG PET/CT, as seen in MPNST, in NF1 patients.

Extra-articular resection of the hip joint for pelvic sarcomas: Are there any oncological and functional risks compared with intra-articular resection?

BACKGROUND: While extra-articular resection (EAR) of the knee and shoulder joint is associated with poorer clinical outcomes, the oncological and functional risks of EAR of the hip joint are unknown. We aimed to compare these risks between EAR of the hip joint and intra-articular resection (IAR). METHODS: We conducted a comparative study of 75 patients who underwent en-bloc tumour resection and limb-salvage reconstruction for bone sarcomas of the peri-acetabulum between 1996 and 2016. We divided patients into two groups for analyses; EAR (n = 21) and IAR (n = 54). RESULTS: There was no statistical difference in oncological outcomes; the 5-year cumulative incidence of disease-specific death was 34% and 35% in the EAR and IAR groups, respectively (p = 0.943), and the 5-year cumulative incidence of LR was 26% and 34%, respectively (p = 0.482). The most common complications were dislocation (28%) and deep infection (28%); there was equally no difference between the groups. The mean Musculoskeletal Tumour Society score was 66% and 65% in the EAR and IAR groups, respectively (p = 0.795), and were significantly lower in patients with deep infection (52% vs. 69%; p = 0.013). In a sub-analysis on the outcomes in patients who underwent PI-uninvolved PII-resection for chondrosarcoma, no major differences in oncologic and functional outcomes were confirmed. CONCLUSION: Patients undergoing EAR and limb-salvage reconstructions of the hip joint have undistinguishable oncological, clinical and functional outcomes compared to those undergoing IAR and reconstructions. If preoperative imaging suggests articular tumour involvement, there appears to be no detrimental effect of undertaking EAR to optimise local control.

Hemangioma of the Rib Mimicking Chondrosarcoma: A Report of Two Cases and Literature Review.

CASES: Case 1 was a 58-year-old man who presented with an incidentally detected, slowly growing mass in the right hypochondrium area. An imaging study showed the mass arising from the 11th rib, with ill-defined margins and cortical destruction. Differential diagnoses included chondrosarcoma and metastatic malignant tumor. Open biopsy was associated with moderate bleeding (300 mL) despite small incision. Microscopic findings showed numerous irregular, dilated, and thin-walled vessels, consistent with the diagnosis of hemangioma of bone, and en bloc excision was performed with no surgical complication. Case 2 was a 49-year-old man who presented with an incidentally detected 4th rib mass with calcification on computed tomography scan. Chondrosarcoma was suspected according to imaging features. An open biopsy was considered to have a risk of tumor seeding because the tumor was located behind the scapula. En bloc excision of the tumor without biopsy was performed. The pathological findings were consistent with hemangioma of bone. CONCLUSION: We reported two cases of rare hemangioma arising from the rib, which mimicked chondrosarcoma. The preoperative diagnosis was challenging, both clinically and radiologically. Because biopsy for hemangioma of the rib is associated with a bleeding risk, the en bloc excision without biopsy can be a practical treatment option.

Regional variation in the survival of patients with a soft-tissue sarcoma of the extremity and trunk wall under a centralized care system : what has been the impact of national policies in the UK?

AIMS: While a centralized system for the care of patients with a sarcoma has been advocated for decades, regional variations in survival remain unclear. The aim of this study was to investigate regional variations in survival and the impact of national policies in patients with a soft-tissue sarcoma (STS) in the UK. METHODS: The study included 1,775 patients with a STS who were referred to a tertiary sarcoma centre. The geographical variations in survival were evaluated according to the periods before and after the issue of guidance by the National Institute for Health and Care Excellence (NICE) in 2006 and the relevant evolution of regional management. RESULTS: There had been a significant difference in survival between patients referred from the North East, North West, East Midlands, West Midlands, South West, and Wales in the pre-NICE era (five-year disease-specific survival (DSS); South West, 74% vs North East, 47% (p = 0.045) or West Midlands, 54% (p = 0.049)), which was most evident for patients with a high-grade STS. However, this variation disappeared in the post-NICE era, in which the overall DSS for high-grade STS improved from 47% to 68% at five years (p < 0.001). Variation in the size of the tumour closely correlated with the variation in DSS, and the overall size of the tumour and incidence of metastasis at the time of diagnosis also decreased after the national policies were issued. CONCLUSION: The survival of patients with a STS improved and regional variation corrected after the introduction of national policies, as a result of a decreasing size of tumour and incidence of metastasis at the time of diagnosis, particularly in patients with a high-grade STS. This highlights the positive impact of national guidelines on regional variation in the presentation, management, and outcome in patients with a STS. Cite this article: Bone Joint J 2021;103-B(9):1541-1549.