Rubble pile asteroids are forever.

Rubble piles asteroids consist of reassembled fragments from shattered monolithic asteroids and are much more abundant than previously thought in the solar system. Although monolithic asteroids that are a kilometer in diameter have been predicted to have a lifespan of few 100 million years, it is currently not known how durable rubble pile asteroids are. Here, we show that rubble pile asteroids can survive ambient solar system bombardment processes for extremely long periods and potentially 10 times longer than their monolith counterparts. We studied three regolith dust particles recovered by the Hayabusa space probe from the rubble pile asteroid 25143 Itokawa using electron backscatter diffraction, time-of-flight secondary ion mass spectrometry, atom probe tomography, and 40Ar/39Ar dating techniques. Our results show that the particles have only been affected by shock pressure of ca. 5 to 15 GPa. Two particles have 40Ar/39Ar ages of 4,219 ± 35 and 4,149 ± 41 My and when combined with thermal and diffusion models; these results constrain the formation age of the rubble pile structure to ≥4.2 billion years ago. Such a long survival time for an asteroid is attributed to the shock-absorbent nature of rubble pile material and suggests that rubble piles are hard to destroy once they are created. Our results suggest that rubble piles are probably more abundant in the asteroid belt than previously thought and provide constrain to help develop mitigation strategies to prevent asteroid collisions with Earth.

What Are the Complication Rates and Factors Associated With Total Femur Replacement After Tumor Resection? Findings From the Japanese Musculoskeletal Oncology Group.

BACKGROUND: Patients undergoing massive tumor resection and total femur replacement (TFR) face a substantial risk of hip dislocation and infection, often resulting in multiple implant revisions or hip disarticulation. These complications can impact their independence and prognosis. Additionally, their shorter life expectancy is influenced by challenges in achieving local radical resection and controlling metastases. Identifying suitable candidates for TFR is vital, necessitating investigations into dislocation, infection, implant failure rates, local recurrence, overall survival, and associated factors. QUESTIONS/PURPOSES: (1) What is the postsurgical complication (hip dislocation and infection) rate and factors associated with postsurgical complications in patients who underwent TFR after tumor resection? (2) What is the local recurrence rate, implant failure rate, overall survival rate, and factors associated with local recurrence and implant failure? METHODS: We retrospectively evaluated 42 patients (median [range] age 47 years [10 to 79 years]) who underwent TFR and tumor resection at the time of the same surgical procedure between 1990 and 2020 at 12 registered institutions that specialized in tumor treatment in Japan. A total of 55% (23) of the patients were men, and 79% (33) had bone sarcoma. The median (range) follow-up period was 36.5 months (2 to 327 months). Of the 42 patients, 12% (5) were lost to follow-up before 2 years without meeting a study endpoint (postsurgical complications, revision, or amputation), and another 19% (8) died before 2 years with implants intact, leaving 69% (29) of the original group who had either follow-up of at least 2 years or met a study endpoint before the minimum surveillance duration. Another 10% (4) had a minimum of 2 years of follow-up but had not been seen in the past 5 years. Infection was defined as deep-seated infection involving soft tissues, bones, joints, and the area around the implant. We did not consider superficial infections. Implant failure was defined when a patient underwent reimplantation or amputation. The complication and implant failure rates were assessed by the cumulative incidence function method, considering competing events. The Kaplan-Meier method was used to estimate the overall survival rate. RESULTS: The 1-month, 6-month, 1-year, and 2-year dislocation rates were 5%, 12%, 14%, and 14%, respectively. The 1-month, 6-month, 1-year, and 2-year infection rates were 5%, 7%, 10%, and 15%, respectively. Multivariable analyses for hip dislocation and infection revealed that resection of the abductor muscles and large tumor size were positively associated with hip dislocation. The 6-month, 1-year, and 2-year local recurrence rates were 5%, 15%, and 15%, respectively. The 6-month, 1-year, 2-year, and 5-year implant failure rates were 5% (95% confidence interval 1% to 15%), 7% (95% CI 2% to 18%), 16% (95% CI 6% to 29%), and 16% (95% CI 6% to 29%), respectively. Multivariable analyses of local recurrence and implant failure that led to reimplantation or amputation revealed that a positive surgical margin was positively associated with local recurrence. The 1-year, 2-year, and 5-year overall patient survival rates were 95% (95% CI 87% to 102%), 77% (95% CI 64% to 91%), and 64% (95% CI 48% to 81%), respectively. CONCLUSION: Hip dislocation, infection, and local recurrence were frequently observed in patients who received massive tumor resection and TFR in our study, eventually leading to reimplantation or amputation. Preserving the abductor muscles and resecting the tumor with a wide margin can prevent postoperative dislocation and local recurrence. Future research should focus on patient selection criteria, prevention of hip dislocation, and innovative treatments. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Comparison of clinical outcome between surgical treatment and particle beam therapy for pelvic bone sarcomas: A retrospective multicenter study in Japan.

BACKGROUND: Few studies have compared the clinical outcomes of patients with pelvic bone sarcomas treated surgically and those treated with particle beam therapy. This is a multicenter retrospective cohort study which compared the clinical outcomes of patients with pelvic bone sarcoma who underwent surgical treatment and particle beam therapy in Japan. METHODS: A total of 116 patients with pelvic bone sarcoma treated at 19 specialized sarcoma centers in Japan were included in this study. Fifty-seven patients underwent surgery (surgery group), and 59 patients underwent particle beam therapy (particle beam group; carbon-ion radiotherapy: 55 patients, proton: four patients). RESULTS: The median age at primary tumor diagnosis was 52 years in the surgery group and 66 years in the particle beam group (P < 0.001), and the median tumor size was 9 cm in the surgery group and 8 cm in the particle beam group (P = 0.091). Overall survival (OS), local control (LC), and metastasis-free survival (MFS) rates were evaluated using the Kaplan-Meier method and compared among 116 patients with bone sarcoma (surgery group, 57 patients; particle beam group, 59 patients). After propensity score matching, the 3-year OS, LC, and MFS rates were 82.9% (95% confidence interval [CI], 60.5-93.2%), 66.0% (95% CI, 43.3-81.3%), and 78.4% (95% CI, 55.5-90.5%), respectively, in the surgery group and 64.9% (95% CI, 41.7-80.8%), 86.4% (95% CI, 63.3-95.4%), and 62.6% (95% CI, 38.5-79.4%), respectively, in the particle beam group. In chordoma patients, only surgery was significantly correlated with worse LC in the univariate analysis. CONCLUSIONS: The groups had no significant differences in the OS, LC, and MFS rates. Among the patients with chordomas, the 3-year LC rate in the particle beam group was significantly higher than in the surgery group.

A Novel Approach to Reducing Lung Metastasis in Osteosarcoma: Increasing Cell Stiffness with Carbenoxolone.

AIM: Primary malignant bone tumor osteosarcoma can metastasize to the lung. Diminishing lung metastasis would positively affect the prognosis of patients. Our previous studies demonstrated that highly metastatic osteosarcoma cell lines are significantly softer than low-metastasis cell lines. We therefore hypothesized that increasing cell stiffness would suppress metastasis by reducing cell motility. In this study, we tested whether carbenoxolone (CBX) increases the stiffness of LM8 osteosarcoma cells and prevents lung metastasis in vivo. METHODS: We evaluated the actin cytoskeletal structure and polymerization of CBX-treated LM8 cells using actin staining. Cell stiffness was measured using atomic force microscopy. Metastasis-related cell functions were analyzed using cell proliferation, wound healing, invasion, and cell adhesion assays. Furthermore, lung metastasis was examined in LM8-bearing mice administered with CBX. RESULTS: Treatment with CBX significantly increased actin staining intensity and stiffness of LM8 cells compared with vehicle-treated LM8 cells (p < 0.01). In Young's modulus images, compared with the control group, rigid fibrillate structures were observed in the CBX treatment group. CBX suppressed cell migration, invasion, and adhesion but not cell proliferation. The number of LM8 lung metastases were significantly reduced in the CBX administration group compared with the control group (p < 0.01). CONCLUSION: In this study, we demonstrated that CBX increases tumor cell stiffness and significantly reduces lung metastasis. Our study is the first to provide evidence that reducing cell motility by increasing cell stiffness might be effective as a novel anti-metastasis approach in vivo.

Advances in treatment of alveolar soft part sarcoma: an updated review.

Alveolar soft part sarcoma is a rare neoplasm of uncertain histogenesis that belongs to a newly defined category of ultra-rare sarcomas. The neoplasm is characterized by a specific chromosomal translocation, der (17) t(X; 17)(p11.2;q25), that results in ASPSCR1-TFE3 gene fusion. The natural history of alveolar soft part sarcoma describes indolent behaviour with slow progression in deep soft tissues of the extremities, trunk and head/neck in adolescents and young adults. A high rate of detection of distant metastasis at presentation has been reported, and the most common metastatic sites in decreasing order of frequency are the lung, bone and brain. Complete surgical resection remains the standard treatment strategy, whereas radiotherapy is indicated for patients with inadequate surgical margins or unresectable tumours. Although alveolar soft part sarcoma is refractory to conventional doxorubicin-based chemotherapy, monotherapy or combination therapy using tyrosine kinase inhibitors and immune checkpoint inhibitors have provided antitumor activity and emerged as new treatment strategies. This article provides an overview of the current understanding of this ultra-rare sarcoma and recent advancements in treatments according to the clinical stage of alveolar soft part sarcoma.

What Are the Complications, Function, and Survival of Tumor-devitalized Autografts Used in Patients With Limb-sparing Surgery for Bone and Soft Tissue Tumors? A Japanese Musculoskeletal Oncology Group Multi-institutional Study.

BACKGROUND: Tumor-devitalized autografts treated with deep freezing, pasteurization, and irradiation are biological reconstruction methods after tumor excision for aggressive or malignant bone or soft tissue tumors that involve a major long bone. Tumor-devitalized autografts do not require a bone bank, they carry no risk of viral or bacterial disease transmission, they are associated with a smaller immunologic response, and they have a better shape and size match to the site in which they are implanted. However, they are associated with disadvantages as well; it is not possible to assess margins and tumor necrosis, the devitalized bone is not normal and has limited healing potential, and the biomechanical strength is decreased owing to processing and tumor-related bone loss. Because this technique is not used in many countries, there are few reports on the results of this procedure such as complications, graft survival, and limb function. QUESTIONS/PURPOSES: (1) What was the rate of complications such as fracture, nonunion, infection, or recurrence in a tumor-devitalized autograft treated with deep freezing, pasteurization, and irradiation, and what factors were associated with the complication? (2) What were the 5-year and 10-year grafted bone survival (free from graft bone removal) of the three methods used to devitalize a tumor-containing autograft, and what factors were associated with grafted bone survival? (3) What was the proportion of patients with union of the tumor-devitalized autograft and what factors were associated with union of the graft-host bone junction? (4) What was the limb function after the tumor-devitalized autograft, and what factors were related to favorable limb function? METHODS: This was a retrospective, multicenter, observational study that included data from 26 tertiary sarcoma centers affiliated with the Japanese Musculoskeletal Oncology Group. From January 1993 to December 2018, 494 patients with benign or malignant tumors of the long bones were treated with tumor-devitalized autografts (using deep freezing, pasteurization, or irradiation techniques). Patients who were treated with intercalary or composite (an osteoarticular autograft with a total joint arthroplasty) tumor-devitalized autografts and followed for at least 2 years were considered eligible for inclusion. Accordingly, 7% (37 of 494) of the patients were excluded because they died within 2 years; in 19% (96), an osteoarticular graft was used, and another 10% (51) were lost to follow-up or had incomplete datasets. We did not collect information on those who died or were lost to follow-up. Considering this, 63% of the patients (310 of 494) were included in the analysis. The median follow-up was 92 months (range 24 to 348 months), the median age was 27 years (range 4 to 84), and 48% (148 of 310) were female; freezing was performed for 47% (147) of patients, pasteurization for 29% (89), and irradiation for 24% (74). The primary endpoints of this study were the cumulative incidence rate of complications and the cumulative survival of grafted bone, assessed by the Kaplan-Meier method. We used the classification of complications and graft failures proposed by the International Society of Limb Salvage. Factors relating to complications and grafted autograft removal were analyzed. The secondary endpoints were the proportion of bony union and better limb function, evaluated by the Musculoskeletal Tumor Society score. Factors relating to bony union and limb function were also analyzed. Data were investigated in each center by a record review and transferred to Kanazawa University. RESULTS: The cumulative incidence rate of any complication was 42% at 5 years and 51% at 10 years. The most frequent complications were nonunion in 36 patients and infection in 34 patients. Long resection (≥ 15 cm) was associated with an increased risk of any complication based on the multivariate analyses (RR 1.8 [95% CI 1.3 to 2.5]; p < 0.01). There was no difference in the rate of complications among the three devitalizing methods. The cumulative graft survival rates were 87% at 5 years and 81% at 10 years. After controlling for potential confounding variables including sex, resection length, reconstruction type, procedure type, and chemotherapy, we found that long resection (≥ 15 cm) and composite reconstruction were associated with an increased risk of grafted autograft removal (RR 2.5 [95% CI 1.4 to 4.5]; p < 0.01 and RR 2.3 [95% CI 1.3 to 4.1]; p < 0.01). The pedicle freezing procedure showed better graft survival than the extracorporeal devitalizing procedures (94% versus 85% in 5 years; RR 3.1 [95% CI 1.1 to 9.0]; p = 0.03). No difference was observed in graft survival among the three devitalizing methods. Further, 78% (156 of 200 patients) of patients in the intercalary group and 87% (39 of 45 patients) of those in the composite group achieved primary union within 2 years. Male sex and the use of nonvascularized grafts were associated with an increased risk of nonunion (RR 2.8 [95% CI 1.3 to 6.1]; p < 0.01 and 0.28 [95% CI 0.1 to 1.0]; p = 0.04, respectively) in the intercalary group after controlling for confounding variables, including sex, site, chemotherapy, resection length, graft type, operation time, and fixation type. The median Musculoskeletal Tumor Society score was 83% (range 12% to 100%). After controlling for confounding variables including age, site, resection length, event occurrence, and graft removal, age younger than 40 years (RR 2.0 [95% CI 1.1 to 3.7]; p = 0.03), tibia (RR 6.9 [95% CI 2.7 to 17.5]; p < 0.01), femur (RR 4.8 [95% CI 1.9 to 11.7]; p < 0.01), no event (RR 2.2 [95% CI 1.1 to 4.5]; p = 0.03), and no graft removal (RR 2.9 [95% CI 1.2 to 7.3]; p = 0.03) were associated with an increased limb function. The composite graft was associated with decreased limb function (RR 0.4 [95% CI 0.2 to 0.7]; p < 0.01). CONCLUSION: This multicenter study revealed that frozen, irradiated, and pasteurized tumor-bearing autografts had similar rates of complications and graft survival and all resulted in similar limb function. The recurrence rate was 10%; however, no tumor recurred with the devitalized autograft. The pedicle freezing procedure reduces the osteotomy site, which may contribute to better graft survival. Furthermore, tumor-devitalized autografts had reasonable survival and favorable limb function, which are comparable to findings reported for bone allografts. Overall, tumor-devitalized autografts are a useful option for biological reconstruction and are suitable for osteoblastic tumors or osteolytic tumors without severe loss of mechanical bone strength. Tumor-devitalized autografts could be considered when obtaining allografts is difficult and when a patient is unwilling to have a tumor prosthesis and allograft for various reasons such as cost or socioreligious reasons. LEVEL OF EVIDENCE: Level III, therapeutic study.

What is a useful marker for predicting survival in patients with high-grade soft tissue sarcoma who have non-inflammatory conditions?

BACKGROUND: The modified Glasgow prognostic score (mGPS) is a reliable system for identifying patients at high risk of death among patients with soft tissue sarcoma (STS). The scoring systems use a combination of C-reactive protein (CRP) and albumin levels. Although patients with high-grade STS are at risk of metastasis and death, even if their mGPS is 0, the prognostic indicators in these patients are unknown. Therefore, we investigated useful prognostic indicators for survival and the development of metastasis in patients with high-grade STS and an mGPS of 0. METHODS: One hundred and four patients with CRP and albumin levels of <1.0 mg/dl and >3.5 g/dl, respectively, indicating an mGPS of 0, were included. The mean follow-up period was 79 months. RESULTS: The 5-year disease-specific survival (DSS) rate was 79.2%. Cox proportional analysis showed that tumor size and absolute neutrophil count (ANC) were prognostic variables in multivariate analyses. Patients with higher ANC (ANC>3370/µl) had a worse DSS than those with lower ANC. The 5-year DSS was 74.7% vs. 91.7%, respectively (p = 0.0207). The 5-year metastasis-free survival was 67.2%. Tumor size and ANC remained significant variables for predicting the development of metastasis in the multivariate analysis. Patients with higher ANC had a worse metastasis-free survival than those with lower ANC. The 5-year metastasis-free survival was 59.5% vs. 87.3%, respectively (p = 0.00269). CONCLUSIONS: When patients with high-grade STS have an mGPS of 0, the ANC and tumor size should be carefully evaluated. A higher neutrophil count and larger tumor size may increase the risk of metastasis development.

Artifactual hypoglycaemia may be common in patients with soft tissue sarcoma who received pegfilgrastim-supported chemotherapy.

BACKGROUND: Recently, we identified artifactual hypoglycemia in patients with soft tissue sarcoma (STS) who received pegfilgrastim-supported chemotherapy. In the present study, we measured white blood cell count and fasting blood glucose levels after the administration of pegfilgrastim in patients with STS and showed the relationship between artifactual hypoglycemia and white blood cell count. PATIENTS: A total of 19 patients were included in this study. The mean age of the patients was 54 years. They received chemotherapy and administration of pegfilgrastim. Pegfilgrastim was injected subcutaneously 48 h after chemotherapy. No patient had a history of diabetes mellitus. RESULTS: Fifty-nine cycles were administered to 19 patients. One hundred and twenty-eight samples were obtained within one week after the of pegfilgrastim administration. Hypoglycemia was observed in 38 of the 13 patients. There were no symptoms of hypoglycemia in any patient. The white blood cell count in samples from patients with hypoglycemia was significantly higher than that in samples without hypoglycemia (p < 0.001). The median white blood cell count in samples with hypoglycemia was 29,415 and 3420 in samples without hypoglycemia. Age, sex, body mass index, performance status, and red blood cell count were not associated with hypoglycemia. White blood cell count was strongly negatively correlated with fasting blood glucose levels (Pearson's r: 0.786, 95% confidence interval: 0.844-0.709, p < 0.001). Of the 38 samples with hypoglycemia, 32 were measured within 2 days after pegfilgrastim administration. CONCLUSION: If a lack of symptoms due to hypoglycemia and leukocytes is confirmed, physicians should wait and identify the normalization of the level of glucose according to the neutrophil nadir following temporal leukocytes, which prevents further invasive examination for hypoglycemia.

Safety and effectiveness of eribulin in Japanese patients with soft tissue sarcoma including rare subtypes: a post-marketing observational study.

BACKGROUND: Soft tissue sarcomas (STSs) are a heterogeneous group of cancers with over 100 described subtypes. While these cancers are infrequent, the prognosis is quite poor, particularly for those with stage IV metastatic disease. Patients for whom curative resection is difficult or those with recurrent metastatic disease are treated with chemotherapy, although the options are very limited. Eribulin is an approved treatment of all STS subtypes in Japan. Efficacy and safety data for the treatment of rare STS subtypes other than liposarcoma and leiomyosarcoma (L-type sarcomas) are limited. This nationwide, multicenter, prospective, post-marketing observational study was conducted to assess the real-world effectiveness and safety of eribulin in Japanese patients with STS. METHODS: Patients with all types of STS and who consented to eribulin treatment were eligible to participate. The observation period was 1 year, starting at treatment initiation, and clinical outcomes were followed up for 2 years after initiating treatment. The primary endpoint was overall survival (OS). Additional outcomes included time-to-treatment failure (TTF), objective response rate (ORR), disease control rate (DCR), and safety. ORR and DCR were evaluated using imaging findings. Effectiveness results were analyzed both for all patients and by STS subtype. RESULTS: A total of 256 patients were enrolled; 252 and 254 were included in the effectiveness and safety analysis set, respectively. Most patients (83.1%) received an initial eribulin dose of 1.4 mg/m2 (standard dose). Respective median OS (95% confidence interval [CI]) was 10.8 (8.5-13.1), 13.8 (10.1-22.3) and 6.5 (5.7-11.1) months for all, L-type, and non-L-type subtypes. The respective median TTF (95% CI) was 2.5 (2.1-2.8), 2.8 (2.3-3.7), and 2.2 (1.6-2.6) months. The ORR and DCR were 8.1 and 42.6%, respectively. Adverse drug reactions (ADRs) and serious ADRs were reported for 83.5 and 18.9% of patients, respectively. The main ADRs were associated with myelosuppression. No significant difference was observed in the incidence of ADRs for patients ≥65 versus <65 years old. CONCLUSIONS: Eribulin demonstrated effectiveness and a manageable safety profile for patients with STS, although the effectiveness of eribulin was not demonstrated for some non-L-type subtypes. TRIAL REGISTRATION: NCT03058406 ( ClinicalTrials.gov ).

Do coagulation or fibrinolysis reflect the disease condition in patients with soft tissue sarcoma?

BACKGROUND: Coagulation and fibrinolysis are distinct processes that are highly correlated. Cells control coagulation and fibrinolysis by expression of tissue factor and urokinase-type plasminogen activator receptor on their surface. Tumor cells express these proteins, adjust their microenvironment and induce tumor exacerbation. We hypothesized that the expression of plasma markers for coagulation and fibrinolysis in patients with soft tissue sarcomas (STSs) was dependent on the level of tumor malignancy. To elucidate which markers are predictive of recurrence, metastasis and prognosis, coagulation or fibrinolysis, we analyzed the correlation between plasma levels of thrombin-antithrombin III complex (TAT), soluble fibrin (SF), plasmin-α2 plasmin inhibitor complex (PIC), D-dimer (DD) and clinical parameters in patients with STSs. METHODS: TAT, SF, PIC or DD were measured in pre-treatment blood samples from 64 patients with primary STSs and analyzed with clinicopathological parameters, and 5-year recurrence free survival (RFS), 5-year metastasis free survival (MFS) and 5-year overall survival (OS) were evaluated. RESULTS: The metastasis group had significantly higher DD (p = 0.0394), PIC (p = 0.00532) and SF (p = 0.00249) concentrations than the group without metastasis. The group that died of disease showed significantly higher DD (p = 0.00105), PIC (p = 0.000542), SF (p = 0.000126) and TAT (p = 0.0373) than surviving patients. By dividing the patients into low and high groups, the group with high DD, PIC, SF and TAT showed significantly lower 5-year MFS and 5-year OS than the corresponding low group. Furthermore, in multivariate COX proportional hazard analysis of continuous variables for 5-year MFS, only PIC was found to be a significant factor (HR: 2.14). CONCLUSION: Fibrinolysis was better than coagulation at reflecting the disease condition of patients with STS. Notably, PIC levels ≥ 1.1 can not only predict the risk of metastasis and poor prognosis, but also increasing PIC levels correspond to further increases in risks of metastasis and poor prognosis.

Short-term clinical outcomes of Kyocera Modular Limb Salvage System designed cementless stems for the endoprosthetic reconstruction of lower extremities: a Japanese Musculoskeletal Oncology Group multi-institutional study.

BACKGROUND: The high rate of aseptic loosening of cemented stems has led to their frequent use in endoprosthetic reconstruction. However, problems, such as stem breakage and stress shielding at the insertion site, remain. The Japanese Musculoskeletal Oncology Group (JMOG) has developed Kyocera Modular Limb Salvage System (KMLS) cementless stems with a unique tapered press-fit and short fixation design. This study aimed to clarify the short-term postoperative outcomes of this prosthesis and validate the stem design. METHODS: One hundred cases of KMLS cementless stems (51 male patients; median age, 49 years; mean follow-up period, 35 months), with a minimum follow-up of 2 years, for the proximal femur (PF), distal femur (DF), and proximal tibia were prospectively registered for use. Prosthesis survival, complication rates, postoperative functional, and radiographical evaluation were analyzed. Complications or failures after insertion of the KMLS endoprostheses were classified into five types and functional results were analyzed according to the MSTS scoring system at postoperative 1 year. The diaphyseal interface and anchorage were graded by the ISOLS system at postoperative 2 years. RESULTS: The overall prosthesis survival rates at 2 and 4 years were 88.2 and 79.6%, respectively. The prosthesis-specific survival rate excluding infection and tumor recurrence was 90.2 and 87.9%, respectively. Younger age (p = 0.045) and primary tumor (p = 0.057) were associated with poor prognosis of prosthesis-specific survival excluding infection and tumor recurrence. Complications were observed in 31 patients, 13 patients underwent revision surgery. The mean MSTS functional score at 1 year postoperatively was 68%. Early implant loosening was significantly more common in the DF (p = 0.006) and PF/DF straight stem (p = 0.038). The ISOLS radiographic evaluation at 2 years after surgery revealed good bone remodeling and anchorage in most cases (bone remodeling: 90% / excellent and good, anchorage: 97% / excellent and good). CONCLUSIONS: Tumor endoprosthesis long-term fixation to the diaphysis of the lower extremity remains challenging. The KMLS cementless stem with a unique tapered press fit design showed good short-term results in maintaining bone stock. To prevent early loosening, a curved stem should be used in PF and DF, but long-term follow-up is necessary.

Treatment Strategy for Elderly Patients with Soft Tissue Sarcoma.

PURPOSE OF REVIEW: Surgical resection is the standard treatment for localized soft tissue sarcoma (STS), while systemic chemotherapy for advanced STS may be considered. However, less aggressive treatment is often administered to elderly patients with STS. Undertreatment may compromise the cure rate and survival of these individuals. We review the literatures and emphasize the importance of standard treatment for STS in elderly patients. RECENT FINDINGS: The outcome of surgical resection of STS in older individuals is comparable to that of younger ones, as long as patients are selected based on American Society of Anesthesiologists Physical Status (ASA-PS). Likewise, systemic treatment may prove beneficial as long as the risk of complications is estimated with a geriatric assessment. Elderly patients with STS benefit from standard treatment as long as the risks of surgical and systemic complications are assessed respectively with the ASA-PS and GA. Novel clinical trials with broader eligibility criteria are also necessary for elderly patients because of the increasing population of the elderly patients in the future.

Clinical outcome in patients who underwent amputation due to extremity soft tissue sarcoma: Tokai Musculoskeletal Oncology Consortium study.

BACKGROUND: Soft tissue sarcomas are a diverse group of rare malignant tumours, mostly occurring in the lower extremities. Amputations are necessary for achieving local control when the soft tissue sarcomas are too large and/or have neurovascular involvement. Patients who require amputation have a poorer prognosis than those who undergo limb-salvage surgery. PATIENTS AND METHODS: We investigated the tumour characteristics and the clinical outcomes in 55 patients with primary soft tissue sarcomas, who underwent amputation. We excluded patients with amputation performed distal to the wrist or ankle joints and those with recurrent soft tissue sarcomas. RESULTS: The mean tumour size was 11.1 cm. Hip disarticulation was performed in 6 patients, 20 underwent above the knee amputation, 8 underwent knee disarticulation and 12 underwent below the knee amputation. Shoulder disarticulation was performed in three patients, five underwent above the elbow amputation, and one underwent below the elbow amputation. The 5-year disease-specific survival rate was 52.8%. The 5-year recurrence-free survival rate and 5-year metastasis-free survival rates were 90.1% and 38.5%, respectively. Larger tumour size, age and the distant metastases at first presentation were predictors of poor prognosis for survival in multivariate analysis. Twenty-eight patients could walk using artificial limbs. The level of amputation (above versus below the knee) showed a significant difference in achieving independent gait. CONCLUSION: Amputation is a useful treatment option for achieving local control in patients with large soft tissue sarcomas. Patients had an opportunity of walking, especially for those who underwent below the knee amputation.

Extraterrestrial ribose and other sugars in primitive meteorites.

Sugars are essential molecules for all terrestrial biota working in many biological processes. Ribose is particularly essential as a building block of RNA, which could have both stored information and catalyzed reactions in primitive life on Earth. Meteorites contain a number of organic compounds including key building blocks of life, i.e., amino acids, nucleobases, and phosphate. An amino acid has also been identified in a cometary sample. However, the presence of extraterrestrial bioimportant sugars remains unclear. We analyzed sugars in 3 carbonaceous chondrites and show evidence of extraterrestrial ribose and other bioessential sugars in primitive meteorites. The 13C-enriched stable carbon isotope compositions (δ13C vs.VPDB) of the detected sugars show that the sugars are of extraterrestrial origin. We also conducted a laboratory simulation experiment of a potential sugar formation reaction in space. The compositions of pentoses in meteorites and the composition of the products of the laboratory simulation suggest that meteoritic sugars were formed by formose-like processes. The mineral compositions of these meteorites further suggest the formation of these sugars both before and after the accretion of their parent asteroids. Meteorites were carriers of prebiotic organic molecules to the early Earth; thus, the detection of extraterrestrial sugars in meteorites establishes the existence of natural geological routes to make and preserve them as well as raising the possibility that extraterrestrial sugars contributed to forming functional biopolymers like RNA on the early Earth or other primitive worlds.

Rare earth element identification and quantification in millimetre-sized Ryugu rock fragments from the Hayabusa2 space mission.

Millimetre-sized primordial rock fragments originating from asteroid Ryugu were investigated using high energy X-ray fluorescence spectroscopy, providing 2D and 3D elemental distribution and quantitative composition information on the microscopic level. Samples were collected in two phases from two sites on asteroid Ryugu and safely returned to Earth by JAXA's asteroid explorer Hayabusa2, during which time the collected material was stored and maintained free from terrestrial influences, including exposure to Earth's atmosphere. Several grains of interest were identified and further characterised to obtain quantitative information on the rare earth element (REE) content within said grains, following a reference-based and computed-tomography-assisted fundamental parameters quantification approach. Several orders of magnitude REE enrichments compared to the mean CI chondrite composition were found within grains that could be identified as apatite phase. Small enrichment of LREE was found for dolomite grains and slight enrichment or depletion for the general matrices within the Ryugu rock fragments A0055 and C0076, respectively. Supplementary Information: The online version contains supplementary material available at 10.1186/s40623-022-01705-3.

The incidence of unplanned excision in patients with soft tissue sarcoma: Reports from the Bone and Soft Tissue Tumor registry in Japan.

BACKGROUND: Due to their rarity, soft tissue sarcomas (STS)s are often treated surgically as unplanned excisions (UE)s before referral to specialists. The Bone and Soft Tissue Tumor (BSTT) registry is a nationwide, organ-specific cancer registry for bone and soft-tissue tumors in Japan. The aim of this study was to elucidate the incidence and risk factors for UEs using data from the BSTT registry. METHODS: Our study comprised 8761 patients with STS including 4826 males and 3935 females, with a mean age of 59 years (range, 0-105 years). Patients were classified into primary STS and UE groups. RESULTS: Superficial and deep tumors were found in 2533 and 6120 patients, respectively. The mean STS size was 8.6 cm (range, 0.2-49 cm). We identified 6610 patients with high-grade, and 1758 patients with low-grade STS. Of the total 8761 patients, 7770 patients had primary STSs, whereas 991 patients were referred after undergoing UE. The UE mean incidence rate over 11 years was 11.3%. The UE incidence rates for leiomyosarcoma (LMS) (odds ratio [OR] = 1.75, p < 0.0001), fibrosarcoma (FS) (OR = 2.28, p < 0.0001), and epithelioid sarcoma (OR = 1.82, p = 0.01) were higher than the mean UE incidence rate (11.3%). Of 757 patients who underwent UE, 354 (47%) patients had superficial (≤5 cm) STSs, whereas 156 (20.6%) of patients had deep STSs (>5 cm) (p < 0.0001). Logistic regression analysis revealed that UE was frequently associated with males and small, superficial, and trunk STSs. CONCLUSIONS: In the present study, the mean UE incidence rate (11.3%) was significantly different from the individual UE incidence rates of histological diagnoses suggesting that surgeons should consider STS, even with small tumors. Continuous education during training for medical students and surgeons is essential to ensure awareness and correct diagnostic procedures for STS.

Is no additional excision after unplanned excision with positive margins justified in patients with small (≤5 cm) high-grade soft-tissue sarcoma?: Analysis from the Bone and Soft Tissue Tumor registry in Japan.

BACKGROUND: This study aimed to elucidate the clinical outcomes of patients with small (≤5 cm) high-grade soft tissue sarcoma, who underwent unplanned excision with positive surgical margin, using data from the Bone and Soft Tissue Tumor registry in Japan. METHODS: We examined 174 patients (101 males and 73 females; mean age, 59 years) with primary non-metastatic soft tissue sarcoma. The tumor size was ≤5 cm, and tumor histological grade was high in all patients. The mean follow-up duration was 50 months. RESULTS: Unplanned excision with R1 and R2 margins was reported in 115 (66%) and 59 patients (34%), respectively. After unplanned excision, immediate additional excision was performed in 154 patients, whereas no additional excision was performed in the remaining 20. Of the 154 patients who underwent additional excision, wide surgical margin resection was achieved in 140 patients, while marginal and intralesional resections were achieved in 10 and 3 patients, respectively. Additionally, 93 patients (60%) underwent reconstruction after additional excision. During the last follow-up, 8 patients died of the disease, 22 developed distant metastasis, and 14 reported local recurrence. The 5-year disease-specific survival rate and 5-year metastasis-free survival rate was 93.5% and 85%, respectively. Tumor depth and additional excision after unplanned excision showed statistical significance in the multivariate analysis. The 5-year metastasis-free survival rate was 89.1% in patients with additional excision and 39.2% in those without. Univariate analysis showed an association between additional excision and local control. The 5-year local recurrence-free survival was significantly worse in patients without additional excision after unplanned excision (52.6%) than in those with additional excision (92.8%). CONCLUSION: If unplanned excision is performed in patients with small high-grade soft tissue sarcoma, additional excision is recommended for preventing metastasis, along with necessary preparations for reconstruction.

Cytoskeletal Actin Structure in Osteosarcoma Cells Determines Metastatic Phenotype via Regulating Cell Stiffness, Migration, and Transmigration.

Osteosarcoma is the most common primary malignant bone tumor. The cause of death due to osteosarcoma is typically a consequence of metastasis to the lung. Controlling metastasis leads to improved prognosis for osteosarcoma patients. The cell stiffness of several tumor types is involved in metastatic potential; however, it is unclear whether the metastatic potential of osteosarcoma depends on cell stiffness. In this study, we analyzed the cell stiffness of the low metastatic Dunn cell line and its highly metastatic LM8 subline, and compared actin organization, cell proliferation, and metastasis. Actin cytoskeleton, polymerization, stiffness, and other cellular properties were analyzed. The organization of the actin cytoskeleton was evaluated by staining F-actin with Alexa Fluor 488 phalloidin. Cell stiffness was measured using Atomic Force Microscopy (AFM). Cell proliferation, migration, invasion, and adhesion were also evaluated. All experiments were performed using mouse osteosarcoma cell lines cultured in the absence and presence of cytochalasin. In LM8 cells, actin polymerization was strongly suppressed and actin levels were significantly lower than in Dunn cells. Stiffness evaluation revealed that LM8 cells were significantly softer than Dunn. Young's modulus images showed more rigid fibrillar structures were present in Dunn cells than in LM8 cells. LM8 cells also exhibited a significantly higher proliferation. The migration and invasion potential were also higher in LM8 cells, whereas the adhesion potential was higher in Dunn cells. The administration of cytochalasin resulted in actin filament fragmentation and decreased actin staining intensity and cell stiffness in both LM8 and Dunn cells. Cells with high metastatic potential exhibited lower actin levels and cell stiffness than cells with low metastatic potential. The metastatic phenotype is highly correlated to actin status and cell stiffness in osteosarcoma cells. These results suggest that evaluation of actin dynamics and cell stiffness is an important quantitative diagnostic parameter for predicting metastatic potential. We believe that these parameters represent new reliable quantitative indicators that can facilitate the development of new drugs against metastasis.

Significance of coagulation and fibrinolysis markers for benign and malignant soft tissue tumors.

BACKGROUND: The intimate relationship between coagulation and fibrinolysis in malignant tumors is a well-known phenomena, with the malignant phenotype enhancing coagulation and fibrinolysis. We hypothesized that soft tissue sarcoma (STS) affects the expression of coagulation and fibrinolysis markers, which could be used to distinguish STS from benign soft tissue tumors. We analyzed the correlations between plasma levels of D-dimer (DD), plasmin-α2 plasmin inhibitor complex (PIC), soluble fibrin (SF), and thrombin-antithrombin III complex (TAT) in benign soft tissue tumors and STS to elucidate whether these markers can be used to predict STS. METHODS: Plasma DD, PIC, SF and TAT levels in primary soft tissue tumors (benign 67, STS 68) were measured before biopsy or treatment. The marker levels were analyzed and compared to various clinicopathological parameters. RESULTS: In malignancy (STS), the average DD, PIC and SF levels were significantly higher than in benign tumors. Multivariate logistic analysis of continuous variables indicated that only PIC exhibited a significant difference (OR: 24.5, 95%CI: 3.55-170, p = 0.0012). Receiver operating characteristic curve analysis produced area under the curve values for DD: 0.691, PIC: 0.784, SF: 0.734 and TAT: 0.588. Youden's index was used to establish thresholds of 0.37 (DD), 0.80 (PIC), 0.90 (SF) and 0.82 (TAT). Threshold values for PIC and SF indicated high specificity (0.881, 0.791) and high positive predictive value (0.818, 0.745), respectively. The highest accuracy value among the markers was observed for PIC (0.704). Significant differences in multivariate analysis of binary variables were demonstrated by categorizing low and high groups based on their threshold, PIC (≥0.80) (OR: 3.36, 95%CI: 1.19-9.43, p = 0.0212) and SF (≥0.90) (OR: 2.63, 95%CI: 1.04-6.66, p = 0.0404) . CONCLUSIONS: Of the coagulation and fibrinolysis markers studied, increased PIC levels were related to STS and over 0.80 PIC was the most suitable for the prediction of STS, which, along with other diagnostic tools, represents a helpful subsidiary tool for the prediction of STS.

Is perioperative chemotherapy recommended in childhood and adolescent patients with synovial sarcoma? A systematic review.

OBJECTIVE: Synovial sarcoma is the most common soft tissue sarcomas among childhood and adolescents, accounting for 8-10% of all soft tissue sarcoma. Synovial sarcoma is considered a relatively chemosensitive tumor compared with other soft tissue sarcomas. However, the role of perioperative chemotherapy in synovial sarcoma remains controversial. The purpose of this systematic review is to evaluate the role of perioperative chemotherapy in childhood and adolescent patients with synovial sarcoma. METHODS: We evaluated studies published between 1 January 1990 and 31 December 2017. The following databases were searched: MEDLINE, Cochrane database (via PubMed) and Ichushi (in Japanese). RESULTS: The search yielded 216 articles in English and Japanese. After the initial screening, based on the title and abstract, 160 articles were excluded. As a second screening, we then assessed the full text of the remaining 56 articles for eligibility. Finally, 10 articles were included in the systematic review. Surgical resection with R0 margin alone was recommended because of the excellent results of two prospective studies. Meta-analysis was performed using data from two retrospective studies of 261 patients. Perioperative chemotherapy did not have a significant effect on survival and event-free survival. CONCLUSIONS: We weakly do not recommend perioperative chemotherapy in patients with non-metastatic synovial sarcoma ≤ 5 cm when R0 resection is acquired. There was no consensus concerning the role of perioperative chemotherapy in patients with synovial sarcoma > 5 cm or those with ≤5 cm who undergo R1 or R2 resection.