Histological diagnostic discrepancy and its clinical impact in bone and soft tissue tumors referred to a sarcoma center.

Histological diagnosis of sarcomas (malignant bone and soft tissue tumors) is challenging due to their rarity, morphological diversity, and constantly evolving diagnostic criteria. In this study, we aimed to assess the concordance in histological diagnosis of bone and soft tissue tumors between referring hospitals and a tertiary sarcoma center and analyzed the clinical impact of the diagnostic alteration. We analyzed 628 consecutively accessioned specimens from 624 patients who visited a specialized sarcoma center for treatment. The diagnoses at referring hospitals and those at the sarcoma center were compared and classified into four categories: agreed, disagreed, specified, and de-specified. Of the 628 specimens, the diagnoses agreed in 403 (64.2%) specimens, whereas some changes were made in 225 (35.8%) specimens: disagreed in 153 (24.3%), specified in 52 (8.3%), and de-specified in 20 (3.2%) cases. The benign/intermediate/malignant judgment changed for 92 cases (14.6%). The diagnostic change resulted in patient management modification in 91 cases (14.5%), including surgical and medical treatment changes. The main inferred reason for the diagnostic discrepancies was a different interpretation of morphological findings of the tumor, which accounted for 48.9% of the cases. This was followed by the unavailability of specialized immunohistochemical antibodies and the unavailability of genetic analysis. In summary, our study clarified the actual clinical impact of diagnostic discrepancy in bone and soft tissue tumors. This may underscore the value of pathology consultation, facilitating access to specialized diagnostic tools, and continued education. These measures are expected to improve diagnostic precision and ultimately benefit patients.

Statistics of Visceral Sarcoma in Japan: Report From the Population-Based National Cancer Registry (NCR) in Japan.

BACKGROUND AND OBJECTIVES: Sarcomas developing in the visceral organs are extremely rare, with no previous reports to describe their national epidemiology. We analyzed Japanese domestic statistics for visceral sarcoma, using the National Cancer Registry (NCR) in Japan, a population-based database launched in 2016. METHODS: We identified 3245 cases of visceral sarcomas in the NCR dated 2016-2019 to analyze demographic and disease information, initial diagnostic process, volume and type of the hospitals, treatment, and prognosis. RESULTS: Visceral sarcoma shows a higher prevalence in the older generation (60+ years), with a significant male predominance (p = 0.006). Leiomyosarcomas occurred frequently in the gastrointestinal tract (N = 240; 39.5%), and angiosarcomas in the liver, gall bladder, pancreas, and spleen (N = 244; 43.9%). Visceral sarcomas were often treated in facilities of lower volume without specific adjuvant treatments (p < 0.001). The cumulative 3-year overall survival was 44.8%, and several factors such as surgery or absence of chemotherapy positively affected survival. CONCLUSIONS: This is the first nationwide study in Japan to analyze the inclusive epidemiology of visceral sarcomas. Visceral sarcomas are characterized by senior and male predominance with relatively poor prognosis, often managed in nonspecialized facilities and rarely with adjuvant therapies. Several histologic subtypes had the propensity to develop in specific organs.

Soft-tissue sarcoma in Japan: National Cancer Registry-based analysis from 2016 to 2019.

BACKGROUND: No previous reports have characterized national profiles of soft-tissue sarcoma overall. We examined the nationwide statistics for soft-tissue sarcoma in Japan using data from the population-based National Cancer Registry. METHODS: We identified 23 522 soft-tissue-sarcoma patients who were entered in the National Cancer Registry during 2016-19 using International Classification of Diseases-Oncology, Third Edition codes for cancer topography and morphology. We extracted data on patient demographics, tumor details (reason for diagnosis, tumor location, histology, extent of disease), hospital volume/type, treatment, and prognosis for each patient. RESULTS: Soft-tissue sarcoma showed a slight male preponderance. Approximately 5500-6000 new cases were diagnosed as soft-tissue sarcoma per year, with the age-adjusted incidence of soft-tissue sarcoma being 3.22/100000/year. The age distribution showed a single peak in the 70-79 age range, and sex-stratified data showed it was higher in men. The most common histologic subtype was liposarcoma. The most frequent tumor locations were the soft tissue and skin, followed by the retroperitoneum. Extent of disease was categorized as: "localized" (31.3%), "regional" (38.9%), or "distant" (10.5%). We found significant associations between overall survival and sex, age, tumor location, facility type, hospital volume, reason for diagnosis, extent of disease, and surgical treatment. CONCLUSIONS: This is the first study to outline the epidemiology, clinical features, treatment, prognosis, and significant factors affecting prognosis of soft-tissue sarcoma in Japan using the National Cancer Registry. Documenting our data regarding elderly patients' outcomes is essential so other countries showing similar population-aging trends can learn from our experiences. LEVEL OF EVIDENCE: Prognostic studies, Level III.

Clear cell sarcoma in Japan: an analysis of the population-based cancer registry in Japan.

BACKGROUND: Clear cell sarcoma is rare, so no reports have previously characterized its national profiles. We examined the nationwide epidemiology and clinical outcomes of patients with clear cell sarcoma based on the National Cancer Registry in Japan. METHODS: Overall, 23 522 patients with soft tissue sarcoma-entered in the National Cancer Registry in 2016-2019 using the International Classification of Diseases for Oncology, Third Edition cancer topography and morphology codes-were enrolled in either the clear cell or the non-clear cell sarcoma group. Data extracted included: demographics (sex and age), tumor details (reason for diagnosis, tumor location, histology and stage), hospital volume and facility type, treatment and prognosis for each patient. RESULTS: Of 23 522 soft tissue sarcoma patients, 122 were enrolled in the clear cell sarcoma group and 23 400 in the non-clear cell sarcoma group. The incidence of clear cell sarcoma was 0.52% of all soft tissue sarcoma, with an age-adjusted incidence of 0.024/100 000/year. The age at diagnosis was significantly younger, and more tumors were at the localized stage in the clear cell than the non-clear cell sarcoma group. In addition, the overall survival in the clear cell group was worse than in the non-clear cell group (P < 0.001). Of 122 patients with clear cell sarcoma, the localized stage, surgical treatment and treatment without chemotherapy were associated with better overall survival in the univariate analyses. CONCLUSIONS: The present study is the first to have clarified the epidemiology, clinical features, treatment, prognosis and significant factors affecting the prognosis of patients with clear cell sarcoma in Japan.

The diagnostic and prognostic value of tartrate-resistant acid phosphatase isoform 5b for giant cell tumor of bone.

BACKGROUND: Serum level of tartrate-resistant acid phosphatase 5b (TRACP5b) is an excellent serum marker of bone resorption. In patients with giant cell tumor of bone (GCTB), TRACP5b levels are reportedly elevated. This study investigated whether TRACP5b could be a diagnostic serum marker and be useful for detecting postoperative disease progression for GCTB. METHODS: Cohort 1: We abstracted data from 120 patients with TRACP5b measurements from our database: 49 patients with GCTB and 71 patients non-GCTB. We compared serum TRACP5b values between the GCTB and non-GCTB groups. Cohort 2 included 47 patients with GCTB who had more than 6 months of follow-up and multiple TRACP5b values. For patients with local recurrence, TRACP5b change rate was calculated by comparing the TRACP5b value just before progression (a) with the value at the time of progression (b): Change rate = [(b)-(a)]/(a). In the non-progression group, the change rate was calculated from the two consecutive TRACP5b values, (c) and (d): Change rate =[(c)-(d)]/(c). We compared TRACP5b change rates between the progression and non-progression groups. RESULTS: Cohort 1: The GCTB group had a significantly higher mean TRACP5b value (1756 ± 2021 mU/dL) than the non-GCTB group (415 ± 219 mU/dL) (p < 0.0001). Cohort 2: The mean TRACP5b change rate of the progression group was significantly higher than the non-progression group (8.53 ± 8.52 and 0.24 ± 0.27, respectively; p < 0.0001). CONCLUSION: TRACP5b is a useful diagnostic marker in GCTB. The rate of change in serum TRACP5b values is a highly sensitive marker for predicting local recurrence in GCTB.

Statistics of bone sarcoma in Japan: report from the population-based cancer registry in Japan.

BACKGROUND: No previous reports have characterized national bone sarcoma profiles overall. We examined the nationwide statistics for bone sarcoma in Japan using data from the National Cancer Registry (NCR), a population-based cancer registry. METHODS: We identified 3,755 patients with bone sarcomas entered in the NCR during 2016-2019 using International Classification of Diseases-Oncology, Third Edition codes for cancer topography and morphology. We extracted data on patient demographics, tumor details (reason for diagnosis, tumor location, histology, extent of disease), hospital volume/type, treatment, and prognosis for each patient. RESULTS: Bone sarcoma showed a slight male preponderance. The age distribution peaked at ages 10-20 and 60-80; approximately 44% of patients were aged over 60 years. Chordoma, chondrosarcoma, and malignant fibrous histiocytoma of bone peaked in the elderly, and Ewing's sarcoma peaked in children. Osteosarcoma had two peaks in Japan as well as in Western countries. The most frequent tumor locations were the limb (45%) and the pelvis (21%). Extent of disease was categorized as: "localized" (39%), "regional" (27%), and "distant" (11%). We found significant associations between overall survival and age, tumor location, facility type, hospital volume, histologic subtype, reason for diagnosis, and extent of disease. The latter had the poorest survival. CONCLUSIONS: This is the first study to outline the epidemiology, clinical features, treatment, prognosis, and significant factors affecting prognosis of bone sarcoma in Japan using the NCR. Documenting our data regarding elderly patients' outcomes is essential so other countries showing similar population-aging trends can learn from our experiences. LEVEL OF EVIDENCE: Prognostic studies, Level III.

Infection of surgery for bone and soft tissue sarcoma with biological reconstruction: Data from the Japanese nationwide bone tumor registry.

BACKGROUND: Although biological reconstruction (such as recycled autograft, vascularized autograft, allograft, or bone transport) is possible for bone defects after malignant bone or soft tissue tumor resection, a high incidence of postoperative complications, including infection, poses a problem. The difficulty in accumulating cases has resulted in a lack of reliable etiological information, such as the incidence and risk factors of postoperative infections. METHODS: We conducted a retrospective study on the nationwide registry data. The primary endpoint was the need for additional surgical intervention for infection control. The overall incidence of postoperative infection and the related risk factors were analyzed. RESULTS: We included 707 malignant bone and soft tissue tumors with biological reconstruction, including recycled autograft, vascularized autograft, allograft, bone transport, and combinations of these. The incidence of postoperative infection was 10.8%. Patients reconstructed by pedicled autograft showed a higher incidence of infection, while cases involving the combination of recycled and pedicled autograft or allograft showed a lower incidence. Independent risk factors for infection included age over 17, tumor diameter over 10 cm, the tumor located on the trunk or being high grade, reconstruction by pedicled autograft, and delayed wound healing. CONCLUSION: Infection incidence was comparable to those in previous reports. Several conventional and novel risk factors were extracted by administering nationwide registry data. Data from the nationwide registry was informative for analyzing the incidence of postoperative infection in biological reconstruction with malignant bone and soft tissue tumor resection.

Predictive value of peripheral blood markers in soft tissue sarcoma patients treated with eribulin.

OBJECTIVE: eribulin, an anticancer agent that inhibits microtubule growth, along with trabectedin and pazopanib, has been approved for the treatment of advanced soft tissue sarcoma (STS). However, there has been no consensus on the optimal second-line therapy among these three agents following treatment failure with doxorubicin. Recently, the effects of eribulin on the tumor microenvironment and immunity have been reported in breast cancer, and peripheral blood immune markers have also been reported to be a predictor of eribulin efficacy, though this remains unverified in STS. We aimed to evaluate the predictive value of various peripheral blood immune markers in STS patients treated with eribulin. METHODS: we retrospectively reviewed the medical records of STS patients treated with eribulin and examined whether peripheral blood immune markers at different time points could be prognostic factors for STS patients treated with eribulin. RESULTS: several peripheral blood immune markers were significantly associated with progression-free survival (PFS), specifically neutrophil-to-lymphocyte ratio (NLR) prestart (NLR before the initial administration of eribulin) (P = 0.019) and absolute lymphocyte count (ALC)8D (ALC on Day 8 of the first administration of eribulin) (P = 0.037). NLR prestart (P = 0.001) was significantly associated with overall survival. The combination of NLR prestart and ALC8D determined the PFS of STS patients treated with eribulin. CONCLUSIONS: the combined indicator of low NLR prestart and high ALC8D predicted the survival of patients treated with eribulin as well as the histology of L-sarcoma. Though further validation was needed, this finding would provide valuable prognostic factor that help treatment decision in the absence of consensus on the optimal second-line therapy following doxorubicin treatment in STS patients.

Incidence and risk of infection in malignant soft tissue tumor resection: Data from the nationwide soft tissue tumor registry.

BACKGROUND: Postoperative infection is a devastating complication in limb salvage surgery for malignant soft tissue tumors. The low absolute case numbers of these rare cancers represent a bottleneck for data collection and analysis. The administration of nationwide registry data is a practical option for the accumulation of cases. METHODS: Data on malignant soft tissue tumor resection were extracted from the Bone and Soft Tissue Tumor Registry in Japan. The incidence of postoperative infection and its risk factors were analyzed. RESULTS: A total of 14,460 cases were included. The incidence of infection was 2.6%. Significant risks for infection were male sex, lower extremity or trunk location, tumor diameter of over 10 cm, trans-compartmental invasion, high grade, autologous bone graft, myocutaneous flap, vascular reconstruction, reconstruction by prosthesis, postoperative radiotherapy, and delayed wound healing. CONCLUSIONS: The incidence was lower than those in the previous studies, perhaps because of less frequent radiotherapy application. Some of the significant risk factors represented local invasiveness of the tumor, suggesting the importance of the preservation of soft tissue for infection prevention. The administration of nationwide registry data was informative for the analysis of infection in malignant soft tissue tumor resection.

Incidence and risk of surgical site infection/periprosthetic joint infection in tumor endoprosthesis-data from the nationwide bone tumor registry in Japan.

BACKGROUND: Surgical site infection (SSI)/periprosthetic joint infection (PJI) is a devastating complication in limb salvage surgery with endoprosthesis reconstruction for malignant bone tumors. The main bottleneck for data collection and analysis for the status of SSI/PJI in tumor endoprosthesis is the low absolute case numbers of this rare cancer. The accumulation of many cases is possible by administrating nationwide registry data. METHODS: The data on malignant bone tumor resection with tumor endoprosthesis reconstruction were extracted from the Bone and Soft Tissue Tumor Registry in Japan. The primary endpoint was defined as the need for additional surgical intervention for infection control. The incidence of postoperative infection and its risk factors were analyzed. RESULTS: A total of 1342 cases were included. The incidence of SSI/PJI was 8.2%. The incidence of SSI/PJI in the proximal femur, distal femur, proximal tibia, and pelvis were 4.9%, 7.4%, 12.6%, and 41.2%, respectively. Location in the pelvis or proximal tibia, tumor grade, indication of myocutaneous flaps, and delayed wound healing proved to be independent risks for SSI/PJI, whereas age, sex, previous surgery, tumor size, surgical margin, application of chemotherapy and radiotherapy were not significant. CONCLUSIONS: The incidence was equal to those in previous studies. The result reconfirmed the high incidence of SSI/PJI in pelvis and proximal tibia cases and cases with delayed wound healing. Novel risk factors such as tumor grade and application of myocutaneous flaps were marked. The administration of nationwide registry data was informative for the analysis of SSI/PJI in tumor endoprosthesis.

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.

Soft tissue sarcoma in adolescent and young adult patients: a retrospective study using a nationwide bone and soft tissue tumor registry in Japan.

OBJECTIVE: The relationship between the adolescent and young adult age groups and poor overall survival in soft tissue sarcoma and the risk factors for poor outcomes in adolescent and young adult patients with soft tissue sarcoma were analyzed. METHODS: The medical records of 7759 Japanese patients diagnosed with soft tissue sarcoma from 2006-13 were accessed from the Bone and Soft Tissue Tumor registry. The epidemiological features of adolescent and young adult patients were compared with those of other age groups. The cancer survival rates were calculated using the Kaplan-Meier method. The prognostic factors for cancer survival were analyzed with the Cox proportional hazards models. The primary endpoint for prognosis was tumor-related death. RESULTS: There were 210 children, 1467 adolescent and young adults, 2771 adults and 3311 elderly among the 7759 patients identified with soft tissue sarcoma. Compared with other age groups, the proportions of myxoid/round cell liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor, primitive neuroectodermal tumor and rhabdomyosarcoma in adolescent and young adult patients were the highest, but none was significantly more prevalent in adolescent and young adult patients. On multivariate analysis, age was not a prognostic factor for poor cancer survival among adolescent and young adult patients with soft tissue sarcoma. The cancer survival rates of adolescent and young adult patients with malignant peripheral nerve sheath tumor were poorer than those of the other age groups; however, adolescent and young adult age was not a prognostic factor on multivariate analysis in malignant peripheral nerve sheath tumor patients. CONCLUSIONS: Our study is the first to investigate soft tissue sarcoma in adolescent and young adult patients using the nationwide Bone and Soft Tissue Tumor registry. Adolescent and young adult age is not a prognostic factor for poor cancer survival among those with soft tissue sarcoma in Japan.

The critical difference in the DASH (Disabilities of the Arm, Shoulder, and Hand) outcome measure after essential upper extremity tumor surgery.

BACKGROUND: The DASH (Disabilities of the Arm, Shoulder, and Hand) is a scored questionnaire that is widely used to evaluate the health-related quality of life of patients with upper limb musculoskeletal disorders. However, numerical changes in the measure scores lack clinical significance without meaningful threshold change values of outcome measures that are diagnostically specific. The minimal clinically important difference (MCID) is useful for the interpretation of scores by defining the smallest change that a patient would perceive. However, the MCIDs of the scores in orthopedic oncology patients has not been reported. We aimed to determine the MCIDs of the measure in orthopedic oncology patients. METHODS: Data from our health-related quality of life database from 1999 to 2005 were retrospectively reviewed after institutional review board approval. Seventy-eight patients who underwent surgery and completed 2 surveys during postoperative follow-up were evaluated. Two different methods were used to estimate the MCIDs: distribution-based and anchor-based approaches (the latter used receiver operating characteristic analysis). RESULTS: Using distribution-based methods, the MCIDs of the DASH questionnaire were 7.4 and 8.3 by half standard deviation and the 90% interval of minimal detectable change, respectively. By anchor-based method (receiver operating characteristic analysis), the MCID was 8.3. CONCLUSION: The MCID values calculated by each method validates that the results for upper extremity oncology patients were similar to those reported in other orthopedic conditions. These results identify the threshold for meaningful improvements in DASH scores in orthopedic oncology patients and establish the reference to evaluate health-related quality of life and the outcomes of upper extremity oncology surgery. These data should be further refined for disease- and reconstruction-specific analyses.

Experimental investigation on the temporal contrast of pre-pulses by post-pulses in a petawatt laser facility.

We experimentally explore the generation of pre-pulses by post-pulses, created through internal reflection in the optical components, by the nonlinear process associated with the B-integral in the laser chain of the petawatt (PW) facility J-KAREN-P. At a large time delay between the main and the post-pulses, we have found that the pre-pulses are not generated from their counterpart post-pulses at an identical time difference before the main pulse, and the temporal shapes of the pre-pulses are greatly distorted asymmetrically. We have also observed that the peak intensities of the pre-pulses are drastically suppressed compared to the expected value at a small time delay. We briefly describe the origins of the pre-pulses generated by the post-pulses and demonstrate the removal of the pre-pulses by switching to optical components with a small wedge angle at our PW laser facility.

What Are the Minimum Clinically Important Differences in SF-36 Scores in Patients with Orthopaedic Oncologic Conditions?

BACKGROUND: The SF-36 is widely used to evaluate the health-related quality of life of patients with musculoskeletal tumors. The minimum clinically important difference (MCID) is useful for interpreting changes in functional scores because it defines the smallest change each patient may perceive. Since the MCID is influenced by the population characteristics, MCIDs of the SF-36 should be defined to reflect the specific conditions of orthopaedic oncology patients. QUESTIONS/PURPOSES: (1) What is the MCID of SF-36 physical component summary (PCS) and mental component summary (MCS) scores in patients with orthopaedic oncologic conditions when calculated with distribution-based methods? (2) What is the MCID of SF-36 PCS and MCS scores in patients with orthopaedic oncologic conditions when calculated by anchor-based methods? METHODS: Of all 960 patients who underwent surgery from 1999 to 2005, 32% (310) of patients who underwent musculoskeletal oncologic surgery and completed two surveys during postoperative follow-up were reviewed. We evaluated a dataset that ended in 2005, completing follow-up of data accrued as part of the cooperative effort between the American Academy of Orthopaedic Surgeons and the Council of Musculoskeletal Specialty Societies to create patient reported quality of life instruments for lower extremity conditions. This effort, started in 1994 was validated and widely accepted by its publication in 2004. We believe the findings from this period are still relevant today because (1) this critical information has never been available for clinicians and researchers to distinguish real differences in outcome among orthopaedic oncology patients, (2) the SF-36 continues to be the best validated and widely used instrument to assess health-related quality of life, and unfortunately (3) there has been no significant change in outcome for oncology patients over the intervening years. SF-36 PCS and MCS are aggregates of the eight scale scores specific to physical and mental dimension (scores range from 0 to 100, with higher scores representing better health). Their responsiveness has been shown postoperatively for several surgical procedures (such as, colorectal surgery). Two different methods were used to calculate the MCID: the distribution-based method, which was based on half the SD of the change in score and standard error of the measurement at baseline, and anchor-based, in which a receiver operating characteristic (ROC) curve analysis was performed. The anchor-based method uses a plain-language question to ask patients how their individual conditions changed when compared with the previous survey. Answer choices were "much better," "somewhat better," "about the same," "somewhat worse," or "much worse." The ROC curve-derived MCIDs were defined as the change in scores from baseline, with sensitivity and specificity to detect differences in patients who stated their outcome was, about the same and those who stated their status was somewhat better or somewhat worse. This approach is based on each patient's perception. It considers that the definition of MCID is the minimal difference each patient can perceive as meaningful. RESULTS: Using the distribution-based method, we found that the MCIDs of the PCS and MCS were 5 and 5 by half the SD, and 6 and 5 by standard error of the measurement. In the anchor-based method, the MCIDs of the PCS and MCS for improvement/deterioration were 4 (area under the curve, 0.82)/-2 (area under the curve, 0.79) and 4 (area under the curve, 0.72)/ (area under the curve, 0.68), respectively. CONCLUSIONS: Since both anchor-based and distribution-based MCID estimates of the SF-36 in patients with musculoskeletal tumors were so similar, we have confidence in the estimates we made, which were about 5 points for both the PCS and the MCS subscales of the SF-36. This suggests that interventions improving SF-36 by less than that amount are unlikely to be perceived by patients as clinically important. Therefore, those interventions may not justify exposing patients to risk, cost, or inconvenience. When applying new interventions to orthopaedic oncology patients going forward, it will be important to consider these MCIDs for evaluation purposes. LEVEL OF EVIDENCE: Level III, diagnostic study.

Minimal clinically important differences in Toronto Extremity Salvage Score for patients with lower extremity sarcoma.

BACKGROUND: The Toronto Extremity Salvage Score (TESS) is the most widely used patient-reported outcome measure for orthopaedic oncology patients. However, minimal clinically important differences (MCIDs) in the TESS have not been analyzed. The aim of this study was to define the MCIDs of TESS in patients with lower extremity sarcoma. METHODS: A total of 85 patients were investigated to calculate the MCIDs for TESS. Three different methods were used: 1) distribution-based methods based on one-half of the standard deviation and standard error of measurement (SEM) at the baseline, 2) anchor-based and receiver operating characteristic (ROC) analysis, and 3) anchor-based using Akaike's Information Criterion (AIC) analysis. RESULTS: The MCIDs at 6 months were 4.9-7.8 by distribution-based methods and 4.3-4.4 by anchor-based methods. The MCIDs at 12 months were 4.0-6.9 by distribution-based methods and 10.6-11.6 by anchor-based methods. CONCLUSIONS: We calculated MCID values for the TESS based on distribution- and anchor-based approaches. Our results seem reasonable since MCIDs calculated by the different approaches had similar values. This knowledge will enable clinicians to identify meaningful functional improvements in sarcoma patients.

Massively parallel sequencing of tenosynovial giant cell tumors reveals novel CSF1 fusion transcripts and novel somatic CBL mutations.

Tenosynovial giant cell tumor (TSGCT) is a rare neoplasm. Although surgical resection is the widely accepted primary treatment for TSGCT, recurrences are frequent, and patients' joint function may be severely compromised. Previous studies reported that CSF1-COL6A3 fusion genes were identified in approximately 30% of TSGCTs. The aim of our study was to comprehensively clarify the genomic abnormalities in TSGCTs. We performed whole exome sequencing in combination with target sequence validation on 34 TSGCT samples. RNA sequencing was also performed on 18 samples. RNA sequencing revealed fusion transcripts involving CSF1, including novel CSF1-VCAM1, CSF1-FN1 and CSF1-CDH1 fusions, in 13/18 (72%) cases. These fusion genes were validated by chromogenic in situ hybridization. All CSF1 fusions resulted in the deletion of CSF1 exon 9, which was previously shown to be an important negative regulator of CSF1 expression. We also found that 12 (35%) of the 34 TSGCT samples harbored CBL missense mutations. All mutations were detected in exons 8 or 9, which encode the linker and RING finger domain. Among these mutations, C404Y, L380P and R420Q were recurrent. CBL-mutated cases showed higher JAK2 expression than wild-type CBL cases (p = 0.013). CSF1 fusion genes and CBL mutations were not mutually exclusive, and both alterations were detected in six of the 18 (33%) tumors. The frequent deletion of CSF1 exon 9 in the fusion transcripts suggested the importance of this event in the etiology of TSGCT. Our results may contribute to the development of new targeted therapies using JAK2 inhibitors for CBL-mutated TSGCT.

Absence of H3F3A mutation in a subset of malignant giant cell tumor of bone.

Giant cell tumor of bone typically involves the epiphysis of the long bones of skeletally mature patients. It is genetically characterized by highly recurrent and specific mutations of the H3F3A gene, which encodes histone H3.3. The most common mutation H3F3A G34W can readily be detected by a recently developed mutation-specific antibody. Giant cell tumor of bone rarely transforms to a sarcoma (malignant giant cell tumor of bone), which has not been genetically characterized in detail. We studied seven clinicopathologically defined malignant giant cell tumors, as well as two H3F3A-mutant bone sarcomas without giant cell tumor histology using a combination of clinicopathological, immunohistochemical, and molecular methods (Sanger sequencing + pyrosequencing or next generation sequencing). The cases included five men and four women, with a median age at initial diagnosis of 27 years. The two H3F3A G34W-positive sarcomas without giant cell tumor histology involved the subarticular epiphyseal sites, suggesting relatedness with giant cell tumor of bone. In two of the seven clinicopathologically defined malignant giant cell tumor cases, the sarcoma tissue showed the H3F3A G34W mutation. However, in the remaining five cases, in contrast to their associated H3F3A G34W-mutant giant cell tumor, the sarcoma lacked the H3F3A G34W mutation, either entirely or sub-clonally in the samples tested. This discordant mutation status was confirmed in all instances by immunohistochemistry and sequencing. A FISH analysis suggested that the absence of the H3F3A G34W mutation may be related to deletion of the H3F3A gene. Therefore, we have demonstrated that H3F3A G34W mutation, a critical driver in giant cell tumor, is absent in a subset of malignant giant cell tumor of bone. This novel recurrent phenomenon has potential biological and diagnostic implications, and further study is required to better characterize this progression pathway and understand its mechanism.

Development of nomograms for prognostication of patients with primary soft tissue sarcomas of the trunk and extremity: report from the Bone and Soft Tissue Tumor Registry in Japan.

BACKGROUND: The use of nomograms for prognostication of individual cancer patients has been recommended in order to facilitate precision medicine. However, models for patients with soft tissue sarcomas (STSs) are limited because of the rarity and heterogeneity of such cancers. In addition, no model has been developed on the basis of an Asian cohort. Here, we attempted to develop and internally validate nomograms for patients with localized STSs of the trunk and extremity. METHODS: This study retrospectively extracted 2827 patients with primary trunk and extremity STSs after definitive surgery using the Bone and Soft Tissue Tumor Registry, which is a nationwide sarcoma database in Japan. We developed three nomograms predicting the probability of local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-specific survival (DSS) at 2 years after surgery, using the Cox multivariate model. The nomograms were internally validated for discrimination and calibration using bootstrap resampling and assessed for their clinical applicability by decision curve analysis (DCA). RESULTS: Local recurrence, distant metastasis and disease-specific death occurred in 241 patients (8.5%), 554 patients (19.6%) and 230 patients (8.1%), respectively. Histological diagnosis, grade and tumor size strongly influenced all three endpoints. The nomograms predicted accurately the probability of LRFS, DMFS and DSS (concordance index: 0.73, 0.70 and 0.75, respectively). DCA demonstrated that our nomograms had clinical applicability. CONCLUSION: We have developed the first nomograms for STSs based on an Asian cohort. These nomograms allowed accurate prediction of LRFS, DMFS and DSS at 2 years after definitive surgery, and can be used as a guide by clinicians for appropriate follow-up and counseling of patients.

Prediction of the pathological fracture risk during stance and fall-loading configurations for metastases in the proximal femur, using a computed tomography-based finite element method.

BACKGROUND: It is important to assess the fracture risk associated with metastasis in the proximal femur. The study aimed to clarify the effect of tumor location on the risk of pathological fracture of the proximal femur and investigate the fracture risk not only in the stance-loading configuration (SC), but also in the fall-loading configuration (FC) using a computed tomography (CT)-based finite element (FE) method based on a simulated metastatic model. METHODS: The axial CT scans of the proximal femora of non-osteoporotic healthy men (n = 4; age range, 42-48 years) and osteoporotic post-menopausal women (n = 4; age range, 69-78 years) were obtained with a calibration phantom, from which the three-dimensional FE models were constructed. A single 15-mm-diameter spherical void simulating a tumor was created at various locations from the neck to subtrochanteric level. Nonlinear FE analyses were performed. RESULTS: The mean predicted fracture loads without spherical voids in the SC were 7700 N in men and 4370 N in women. With the void at the medial femoral neck and in the region anteromedial to lesser trochanter, the mean predicted fracture load significantly reduced to 51.3% and 59.4% in men and 34.1% and 64.5% in women, respectively. The mean predicted fracture loads without a spherical void in the FC were 2500 N in men and 1862 N in women. With the void at the medial and posterior femoral neck, the predicted fracture load was significantly reduced to 65.7% and 79.7% in men and 48.3% and 65.4% in women, respectively. CONCLUSIONS: These results showed that the risk of pathologic fracture was quite high in both the SC and FC when the lytic lesion existed along the principal compressive trabecular trajectory or posterior neck. Prophylactic intervention should be considered for metastases at these locations.