Clinical Outcome in Patients With High-grade Soft-tissue Sarcoma Receiving Prosthetic Replacement After Tumor Resection of the Lower Extremities: Tokai Musculoskeletal Oncology Consortium Study.

AIM: This multicenter retrospective study aimed to clarify the surgical and oncological outcomes of patients with high-grade soft tissue sarcoma (STS) who underwent prosthetic replacement reconstruction after lower extremity tumor resection. PATIENTS AND METHODS: We retrospectively collected the data of 27 patients with high-grade STS. The mean follow-up duration after prosthetic replacement was 44.7 months. RESULTS: The mean age at surgery was 63 years. The mean tumor size was 16 cm. For reconstruction, proximal femur replacement was performed in 15 patients, distal femur replacement in six, and total femur replacement in six. The major complications were infections in nine patients and aseptic loosening in four. Nine patients developed local recurrence. The cause of revision surgery was infection in five patients, aseptic loosening in three, and metal allergy in one. The 5-year prosthetic survival rate was 51.1%. At the final follow-up, amputation was performed in five patients. The 5-year limb salvage rate was 76.8%. The mean functional score of the 25 patients who could be assessed was 16.0 (53%). Of the 27 patients, five were excluded from the survival analysis because they underwent prosthetic replacement for local recurrence. The 5-year overall survival rate in the remaining 22 patients was 45.3%. CONCLUSION: We identified a high rate of surgical complications and poor survival in patients with high-grade STS who underwent tumor resection and reconstruction using prosthetic replacement of the lower extremities, although limb salvage was achieved in 81.5% of the patients. Careful follow-up is needed for surgical complications and oncological events after surgery.

A clinical trial of a unidirectional porous tricalcium phosphate filling for defects after resection of benign bone lesions: a prospective multicenter study.

Affinos (Kuraray, Japan) is a ß-tricalcium phosphate bone substitute with a unidirectional porous structure. This study aimed to investigate its efficacy on the healing process after filling for bone defects. Fifty-six patients who met the inclusion criteria were divided into cohort 1 (n = 30), including bones other than phalanges and metacarpal/tarsal bones, and cohort 2 (n = 26), including phalanges and metacarpal/tarsal bones. Semi-quantified scores for material resorption and trabeculation through the defect were evaluated with radiographs after surgery. In some patients, levels of bone metabolic markers were assessed. The values of resorption and trabeculation increased steadily with time, and trabeculation progressed compared with resorption in both cohorts. In cohort 1, multiple regression analyses showed that the diaphyseal lesion, smaller defect volume, and increased resorption values at 3 months were associated with increased values of resorption 12 months after surgery (R2 = 0.66, p < 0.001). The trabeculation values at 2 months were positively related to the trabeculation values 12 months after surgery (R2 = 0.35, p = 0.002). In cohort 2, the increased resorption values at 2 months and smaller defect volume significantly correlated with the increased resorption values 12 months after surgery (R2 = 0.58, p < 0.001). The ratio from the baseline of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen at 3 months was negatively associated with the trabeculation values 12 months after surgery (R = - 0.791, p = 0.004). Evaluation of radiographic images and bone metabolic markers in the early postoperative period may predict the healing status at 12 months postoperatively in the defects followed by Affinos filling.

Clinical features and treatment outcomes of dedifferentiated and grade 3 chondrosarcoma: A multi-institutional study.

Chondrosarcoma is the second most common primary malignant bone tumor. In this multicenter study, we sought to evaluate the disease-specific survival (DSS) and disease-free survival (DFS), and prognostic factors in patients with dedifferentiated chondrosarcoma (DDCS) or grade 3 chondrosarcoma (G3CS) in Japan. We retrospectively investigated the treatment outcomes and prognostic factors in 62 patients with DDCS and 19 patients with G3CS at 15 institutions participating in the Japanese Musculoskeletal Oncology Group. We also clarified significant clinicopathological factors for oncological outcomes. In surgery for primary lesions aimed at cure, a histologically negative margin (R0) was obtained in 93% (14/15) of patients with G3CS and 100% (49/49) of patients with DDCS. The 5-year DSS was 18.5% in patients with DDCS and 41.7% in patients with G3CS (p = 0.13). Local control was obtained in 80% (12/15) and 79.6% (39/49) of patients with G3CS and DDCS in the primary lesion after surgery with a wide surgical margin, respectively. In multivariate analysis, stage and no treatment/palliative treatment for the primary lesion were independent prognostic factors for DSS of DDCS, and age and no treatment/palliative treatment for DSS of G3CS. The 5-year DFS rate was 22.8% in 26 patients with DDCS who did not receive adjuvant chemotherapy, and 21.4% in 14 patients who received adjuvant chemotherapy. The prognosis of DDCS remains poor, although R0 resection was carried out in most cases. Effective and/or intensive chemotherapeutic regimens or agents should be considered or developed for patients with high-grade chondrosarcoma, particularly for those with DDCS.

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.

Clinical Outcome in Soft Tissue Sarcoma Patients with Lung Metastasis Who Received Metastasectomy and/or Radiofrequency Ablation: Tokai Musculoskeletal Oncology Consortium Study.

PURPOSE: Here, we investigated the oncological outcomes of lung metastasectomy and/or radiofrequency ablation (RFA) of 92 patients with soft tissue sarcoma (STS) at nine institutions. METHODS: The study cohort included 65 men and 27 women with a mean age of 59 years at the time of metastasis. The mean follow-up duration was 51 months. All patients underwent metastasectomy and/or RFA for lung metastasis. RESULTS: The mean maximum size of the initial lung metastasis was 14.6 mm. At the initial evaluation, 41 patients had a single metastasis, whereas 51 patients had multiple metastases. The mean number of metastasectomies and/or RFA was 2 per patient. A total of 70 patients underwent lung metastasectomy, whereas the other 13 underwent lung RFA. The remaining nine patients underwent both RFA and metastasectomy. The 5-year post-metastatic survival rate was 52%. The patients who underwent complete treatment for the initial metastasis had better post-metastatic survival rates than those who underwent incomplete treatment. A univariate analysis of all possible prognostic factors for complete treatment confirmed the predictive value of disease-free interval, metastasis at initial presentation, distribution, tumor size, and number of lung metastases. Of the 92 patients, 74 underwent complete treatment for initial metastasis; in these patients, univariate and multivariate analyses showed that a smaller tumor size and single-lung metastasis were prognostic factors for superior post-metastatic survival. The patients with a smaller (<11.5 mm) single metastasis had better post-metastasis survival. The 5-year post-metastatic survival rates were 89.9% for patients with a smaller (<11.5 mm) single metastasis versus 22.7% for patients with larger (>11.5 mm) and multiple metastases. DISCUSSION: We propose that complete treatment for lung metastasis in patients with STS may improve post-metastatic survival rates. Furthermore, tumor number and size are important variables for clinical decision-making.

Tumor location and type affect local recurrence and joint damage in tenosynovial giant cell tumor: a multi-center study.

Osteochondral destruction and a high recurrence rate after surgery are major concerns that make difficult the treatment course of tenosynovial giant cell tumor. The aims of this study were to elucidate rates of postoperative local recurrence and osteochondral destruction, as correlated with various demographic factors. Eighty surgically treated patients with intra-articular tumors (knee: 49, ankle and foot: 12, hip: 10, others: 9) were included in this study. Factors including age, disease type (diffuse/localized), location, existence of osteochondral destruction were correlated with local recurrence or development/progression of osteochondral destruction. The 5-year local recurrence free survival rate was 71.4%. Diffuse type (n = 59, localized: n = 21) (P = 0.023) and knee location (P = 0.002) were independent risk factors for local recurrence. Diffuse type (P = 0.009) was a significant risk factor, and knee location (P = 0.001) was a negative factor for osteochondral destruction at the initial examination. Progression of osteochondral destruction was observed more often in cases with local recurrence (P = 0.040) and findings of osteochondral destruction at the initial examination (P = 0.029). Diffuse type is a factor that should be noted for both local recurrence and osteochondral destruction, while local recurrence occurs but osteochondral destruction is less observed in the knee.

Effect of Neoadjuvant Therapies on Soft Tissue Sarcomas with Tail-like Lesions: A Multicenter Retrospective Study.

Several types of soft tissue sarcomas have peripheral infiltrative growth characteristics called tail-like lesions. The efficacy of neoadjuvant therapy for tumors with tail-like lesions has not been elucidated. From 2012 to 2019, we analyzed 36 patients with soft tissue sarcoma with tail-like lesions treated with neoadjuvant therapy, including chemotherapy, radiotherapy, or both. The effect of neoadjuvant therapy on the tail sign was investigated by analyzing the change in tail-like lesions during neoadjuvant therapy and histological responses. The median length of the tail-like lesion reduced from 29.5 mm at initiation to 19.5 mm after neoadjuvant therapy. The extent of shrinkage in tail-like lesions was related to the histopathological responses in the main part of the tumor. Complete disappearance of the tail-like lesion was observed in 12 patients; however, it was not related to achieving a microscopically negative margin. The oncologic outcomes did not significantly differ between cases with and without the complete disappearance of tail-like lesions. This study indicated that the shrinkage of tail-like lesions did not have a significant effect on complete resection or improvements of clinical outcomes. A more comprehensive evaluation is needed to elaborate on the surgical strategy.

The clinical outcome of eribulin treatment in Japanese patients with advanced soft tissue sarcoma: a Tokai Musculoskeletal Oncology Consortium study.

The efficacy and safety of eribulin in Japanese patients with advanced soft-tissue sarcomas (STS) have not been evaluated in a large-scale cohort study. Thus, we aimed to investigate the clinical outcome of 82 Japanese patients with STS receiving eribulin across multiple study centers retrospectively. Of 82 STS patients receiving eribulin treatment, 13 were treated for locally unresectable tumor, 46 for metastasis, and 23 for both. The primary endpoint of this study was to evaluate the efficacy of eribulin against STS. The median age was 60 years. Thirty-seven were diagnosed with L-sarcoma (leiomyosarcoma or liposarcoma) and 45 had non-L-sarcoma. The median progression-free survival (PFS) for all patients was 2.7 months, with 3.4 months in those with L-sarcoma and 2.2 months in those with non-L-sarcoma. Patients with L-sarcoma showed a better PFS than those with non-L-sarcoma. Overall, the median survival time was 11.1 months, and 12.3 months and 7.9 months in patients with L-sarcoma and non-L-sarcoma, respectively; however, there was no significant differences between the groups. The prognostic significance of PS = 0 and both existence of local and metastatic STS was evaluated by multivariate analysis. We also evaluated the overall survival (OS) in patients with undifferentiated pleomorphic sarcoma (UPS) and other non-L-sarcomas. Patients with UPS had better OS than those with the other non-L-sarcomas. In conclusion, there was a significant difference in PFS between patients with L-sarcoma and non-L-sarcoma following treatment with eribulin. The anti-tumor potential of eribulin was evident in patients with UPS.

Surgical complication and postoperative pulmonary function in patients undergoing tumor surgery with thoracic wall resection.

Postoperative complications of thoracic wall resection include respiratory complications, skin necrosis and infection. The aim of the present study was to examine postoperative complications in patients who required combined thoracic wall resection during the surgical removal of a tumor. The present study included 68 patients; there were 50 patients with lung tumors and 18 patients with musculoskeletal tumors. The clinical factors associated with complications were compared between the two groups. Preoperative and postoperative pulmonary function tests were performed to examine the residual pulmonary function in 16 patients. Thoracic cage reconstruction was performed in 46 patients. Postoperative complications occurred in 30 (44.1%) patients, and one patient died from postoperative pneumonitis. Compared with the pulmonary function preoperative test results, the postoperative results revealed a decrease in the mean vital capacity percentage and an increase in the mean forced expiratory volume within 1 sec as a percent of the forced vital capacity. In patients with lung tumors, pneumonectomy can result in an increased rate of complications following thoracic wall resection. Residual pulmonary function is affected by impaired thoracic cage expansion and removal of the lung. However, the results of the present study demonstrated that these complications can be somewhat stabilized by thoracic wall reconstruction.

Conditional knockdown of hyaluronidase 2 in articular cartilage stimulates osteoarthritic progression in a mice model.

The catabolism of hyaluronan in articular cartilage remains unclear. The aims of this study were to investigate the effects of hyaluronidase 2 (Hyal2) knockdown in articular cartilage on the development of osteoarthritis (OA) using genetic manipulated mice. Destabilization of the medial meniscus (DMM) model of Col2a promoter specific conditional Hyal2 knockout (Hyal -/- ) mice was established and examined. Age related and DMM induced alterations of articular cartilage of knee joint were evaluated with modified Mankin score and immunohistochemical staining of MMP-13, ADAMTS-5, KIAA11199, and biotinylated- hyaluronan binding protein staining in addition to histomorphometrical analyses. Effects of Hyal2 suppression were also analyzed using explant culture of an IL-1α induced articular cartilage degradation model. The amount and size of hyaluronan in articular cartilage were higher in Hyal2 -/- mice. Hyal2 -/- mice exhibited aggravated cartilage degradation in age-related and DMM induced mice. MMP-13 and ADAMTS-5 positive chondrocytes were significantly higher in Hyal2 -/- mice. Articular cartilage was more degraded in explant cultures obtained from Hyal2 -/- mice. Knockdown of Hyal2 in articular cartilage induced OA development and progression possibly mediated by an imbalance of HA metabolism. This suggests that Hyal2 knockdown exhibits mucopolysaccharidosis-like OA change in articular cartilage similar to Hyal1 knockdown.

Heat-stimuli-enhanced osteogenesis using clinically available biomaterials.

A recent study reported that heat stress stimulates osteogenesis in an in vivo rat model using alginate gel and magnetite cationic liposomes. However, for clinical use, the efficacy for promoting osteogenesis needs to be investigated using clinically approved materials, and preferably with animals larger than rats. The aim of this study was to evaluate multiple heat stimuli-triggered osteogenesis in rat tibial defect models using already clinically applicable materials (Resovist® and REGENOS®) and determine the efficacy also in the rabbit. Fifty-eight rats and 10 rabbits were divided into two groups, respectively, with or without hyperthermia treatment at 45°C for 15 min. (hyperthermia; 20 rats once a week, 8 rats three times a week, 5 rabbits once a week, control; 30 rats and 5 rabbits). Micro-CT assessment at 4 weeks revealed that a significantly stimulated osteogenesis was observed in the once a week group of both rats and rabbits as compared to the control group (p = 0.018 and 0.036, respectively). In contrast, the three times a week group did not show enhanced osteogenesis. Histological examination and image analysis showed consistent results in which the area of mineralized bone formation in the once a week hyperthermia group was significantly increased compared with that in the control group at four weeks (rat; p = 0.026, rabbit; p = 0.031). Newly formed bone was observed in the grafted materials from the periphery toward the center, and more osteoclasts were found in the once a week group. Heat stress also induced enhanced alkaline phosphatase expression in cultured osteoblastic cells, MC3T3, in vitro (p = 0.03). On the other hand, heat stress had no obvious effects on chondrogenic differentiation using ATDC5 cells. Our study demonstrates that heat-stimuli with clinically applicable novel heating materials can promote significant osteogenesis, and may thus be a promising treatment option for diseases associated with bone defects.

Antitumor effects of 4-methylumbelliferone, a hyaluronan synthesis inhibitor, on malignant peripheral nerve sheath tumor.

Hyaluronan (HA) has been shown to play important roles in the growth, invasion and metastasis of malignant tumors. Our previous study showing that high HA expression in malignant peripheral nerve sheath tumors (MPNST) is predictive of poor patient prognosis, prompted us to speculate that inhibition of HA synthesis in MPNST might suppress the tumorigenicity. The aim of our study was to investigate the antitumor effects of 4-methylumbelliferone (MU), an HA synthesis inhibitor, on human MPNST cells and tissues. The effects of MU on HA accumulation and tumorigenicity in MPNST cells were analyzed in the presence or absence of MU in an in vitro as well as in vivo xenograft model using human MPNST cell lines, sNF96.2 (primary recurrent) and sNF02.2 (metastatic). MU significantly inhibited cell proliferation, migration and invasion in both MPNST cell lines. HA binding protein (HABP) staining, particle exclusion assay and quantification of HA revealed that MU significantly decreased HA accumulation in the cytoplasms and pericellular matrices in both MPNST cell lines. The expression levels of HA synthase2 (HAS2) and HA synthase3 (HAS3) mRNA were downregulated after treatment with MU. MU induced apoptosis of sNF96.2 cells, but not sNF02.2 cells. MU administration significantly inhibited the tumor growth of sNF96.2 cells in the mouse xenograft model. To the best of our knowledge, our study demonstrates for the first time the antitumor effects of MU on human MPNST mediated by inhibition of HA synthesis. Our results suggest that MU may be a promising agent with novel antitumor mechanisms for MPNST.

Impact of disease free status on prognosis in metastatic non-small round cell soft tissue sarcomas.

The aim of this study is to examine the impact of disease free (DF) status on the prognosis in patients with metastatic non-small round cell soft tissue sarcoma (STS). We retrospectively reviewed 51 metastatic STS patients who were treated in Nagoya University Hospital from 2005 to 2015. The relation between various clinical factors and overall survival (OS) was analyzed. The log rank test and Cox's proportional hazards test were used to evaluate the differences between groups. p-values of <0.05 were considered to indicate significance. The median follow-up period after first metastasis was 23.5 (1.6-97.1) months. There were 30 males and 21 females with a median age of 62 (15-88) years at first metastasis. The histologic subtypes were 17 undifferentiated pleomorphic sarcoma, 10 liposarcoma, 8 malignant peripheral nerve sheath tumor, and 16 others. Thirty patients had more than 2 metastases, and 15 patients had primary or local recurrent tumors. The metastatic sites were 31 lung only, 8 bone only, and 12 others. Twenty-two patients achieved DF status after surgeries and in one case proton radiotherapy for bone metastasis. DF status was marginally or significantly associated with good prognosis in patients with both pulmonary (p = 0.055) and extrapulmonary metastasis (p = 0.029). On multivariate analysis, DF status (p = 0.010) was an independent good prognostic factors for OS. In metastatic non-small round cell STS, it is an important treatment concept to achieve DF status whenever possible. This concept can apply both to pulmonary and extrapulmonary metastasis.

Simple resection of truncal desmoid tumors: A case series.

Desmoid tumors of the extra-abdominal and abdominal wall have been associated with morbidity due to the aggressive nature of the surgery and high recurrence rates. Surgery that does not cause functional impairment is desired for patients with desmoid tumors. In the present study, among patients with desmoid tumors who were prospectively and consecutively treated with identical conservative treatment with meloxicam, a selected patients of patients were treated with less invasive surgery than wide-resection. Out of 60 patients pathologically diagnosed with desmoid tumors, 9 patients with tumors refractory to conservative treatment and 4 patients who refused to receive this type of treatment were treated with planned simple resection. Subsequently, the clinical outcome of the patients and the mutational status of the catenin ß-1 (CTNNB1) gene in the tumors were analyzed. The mean age of the 13 patients that underwent planned simple resection was 39 years, and the tumors were located in the abdominal wall in 6 cases, the chest wall in 4 cases and the neck in 3 cases. All excised specimens were evaluated and positive microscopic margins were identified; however, during the mean follow-up period of 30 months, 12/13 cases, 7 of which had T41A mutations and 5 of which had no mutations (wild-type), did not develop recurrence. Only 1 initial case with an S45F mutation in the CTNNB1 gene developed recurrence. The results of the present prospectively treated with simple resection and retrospectively analyzed study suggest that planned simple resection could serve as a therapeutic modality for extraperitoneal desmoid tumors, particularly truncal ones with a wild-type or T41A mutational status.

Giant cell tumor of bone arising in long bones possibly originates from the metaphyseal region.

Giant cell tumor of bone (GCTB) is a primary benign bone tumor with a locally aggressive character. Definitive descriptions of the site of origin for this type of tumor are not available. The aim of the present study was to evaluate the site of origin of GCTB of long bones with regards to epiphyseal lines by means of radiographic examination. For that purpose, plain X-ray scans of 71 GCTBs arising in long bones were retrospectively reviewed. The tumor locations were the distal femur in 31 cases, proximal femur in 11 cases, proximal tibia in 13 cases, distal radius in 6 cases, proximal humerus in 5 cases and proximal fibula in 5 cases. The vertical center (VC) of the tumor was determined with X-ray anteroposterior view, and the correlation between the VC and the epiphyseal line, and between the distance from the epiphyseal line to the VC and tumor area or volume were analyzed using a regression model equation based on scatter plot diagrams. The VC of the tumor was located in the metaphyseal region in 57 cases, in the epiphyseal line in 11 cases and in the epiphyseal region in 3 cases. In cases of GCTB located in the distal femur or proximal tibia, significant correlations between the distance from the VC to the epiphyseal line and tumor area or volume were identified. The site of origin of GCTB was estimated to be located in the metaphyseal region. GCTB often occurs in mature patients, which renders it challenging to estimate the true site of origin of this lesion, since the metaphyseal line has disappeared in mature patients. The results of the present study suggest that GCTB possibly originates in the metaphyseal region.

Characteristics of cultured desmoid cells with different CTNNB1 mutation status.

Desmoid tumors are benign mesenchymal neoplasms with a locally aggressive nature. The mutational status of ß-catenin gene (CTNNB1) is presumed to affect the tumorous activity of the cells. In this study, we isolated three kinds of desmoid cell with different CTNNB1 status, and compared their characteristics. Cells were isolated from three patients with abdominal wall desmoid during surgery, all of which were resistant to meloxicam treatment. The mutational status of the CTNNB1 exon 3 was determined for both parental tumor tissues and isolated cultured cells. ß-catenin expression was determined with immunohistochemistry. Responsiveness to meloxicam was investigated with MTS assay together with COX-2 immunostaining. mRNA expressions of downstream molecules of Wnt/ß-catenin pathway were determined with real-time RT-PCR. Three kinds of cell isolated from desmoid tumors harboring different CTNNB1 mutation status (wild type, T41A, and S45F), all exhibited a spindle shape. These isolated cells could be cultured until the 20th passage with unchanged proliferative activity. Nuclear accumulation of ß-catenin was observed in all cultured cells, particularly in those with S45F. Proliferating activity was significantly suppressed by meloxicam (25 µmol/L, P < 0.007) in all three cell cultures, of which parental desmoid was resistant to meloxicam clinically. The mRNA expressions of Axin2, c-Myc, and Cyclin D1 differently increased in the three cultured cell types as compared with those in human skin fibroblast cells (HDF). Inhibitors of Wnt/ß-catenin pathway downregulated Axin2, c-Myc, and Cyclin D1 significantly. Isolated and cultured desmoid tumor cells harboring any one of the CTNNB1 mutation status had unique characteristics, and could be useful to investigate desmoid tumors with different mutation status of CTNNB1.

Increased expression and activation of cathepsin K in human osteoarthritic cartilage and synovial tissues.

Few studies have analyzed Cathepsin K (CatK) expression in human osteoarthritic tissues. We investigated CatK expression and activation in human articular cartilage using clinical specimens. Human osteoarthritic cartilage was obtained during surgery of total hip arthroplasty (n = 10), and control cartilage was from that of femoral head replacement for femoral neck fracture (n = 10). CatB, CatK, CatL, CatS, and Cystatin C (CysC) expressions were evaluated immunohistochemically and by real-time PCR. Intracellular CatK protein was quantified by ELISA. Intracellular CatK activity was also investigated. Osteoarthritis (OA) chondrocytes were strongly stained with CatK, particularly in the superficial layer and more damaged areas. CatB, CatL, CatS, and CysC were weakly stained. CatK mRNA expression was significantly higher in OA group compared to that in control group (p = 0.043), whereas those of CatB, CatL, CatS, and CysC did not differ significantly. Mean CatK concentration (4.83 pmol/g protein) in OA chondrocytes was higher than that (3.91 pmol/g protein) in control chondrocytes (p = 0.001). CatK was enzymatically more activated in OA chondrocytes as compared with control chondrocytes. This study, for the first time, revealed increased CatK expression and activation in human OA cartilage, suggesting possible crucial roles for it in the pathogenesis of osteoarthritic change in articular cartilage.

Development and external validation of nomograms predicting distant metastases and overall survival after neoadjuvant chemotherapy and surgery for patients with nonmetastatic osteosarcoma: A multi-institutional study.

BACKGROUND: In this era of individualized cancer treatment, data that could be applied to predicting the survival of patients with osteosarcoma are still limited because of the rarity of the disease and the difficulty in accumulating a sufficient number of patients. Therefore, a multi-institutional collaboration was implemented to develop and externally validate nomograms that would predict metastasis-free survival (MFS) and overall survival (OAS) for patients with nonmetastatic osteosarcoma. METHODS: This study retrospectively examined 1070 patients treated with neoadjuvant chemotherapy and surgery for nonmetastatic osteosarcoma. Data from Japanese patients (n = 557) were used to develop multivariate nomograms based on Cox regression. Six clinical and pathologic variables were built into nomograms estimating the probability of MFS and OAS 3 and 5 years after diagnosis. The model was internally validated for discrimination and calibration with bootstrap resampling and was externally validated with an independent patient cohort from Korea (n = 513). RESULTS: A patient's age, tumor site, and histologic response were found to have a stronger influence on MFS and OAS in the model than sex, tumor size, or pathologic fracture. The nomograms and calibration plots based on these results well predicted the probability of MFS (concordance index, 0.631) and OAS (concordance index, 0.679). The concordance indices for external validation were 0.682 for MFS and 0.665 for OAS. CONCLUSIONS: The nomograms were externally validated and verified to be useful for the prediction of MFS and OAS and for the assessment of the postoperative prognosis. They can be used for counseling patients and for establishing appropriate surveillance strategies after surgery.

Inhibition of hyaluronan synthesis alters sulfated glycosaminoglycans deposition during chondrogenic differentiation in ATDC5 cells.

In chondrogenic differentiation, expression and collaboration of specific molecules, such as aggrecan and type II collagen, in extracellular matrix (ECM) are crucial. However, few studies have clarified the roles of hyaluronan (HA) in proteoglycan aggregation during chondrogenic differentiation. We assessed the roles of HA in sulfated glycosaminoglycans deposition during chondrogenic differentiation by means of 4-methylumbelliferone (4-MU), an HA synthase inhibitor, using ATDC5 cells. ATDC5 cells were treated with 0.5 mM 4-MU for 7 or 21 days after induction of chondrogenic differentiation with insulin. Depositions of sulfated glycosaminoglycans were evaluated with Alcian blue staining. mRNA expression of ECM molecules was determined using real-time RT-PCR. The deposition of aggrecan and versican was investigated with immunohistochemical staining using specific antibodies. Effects of 4-MU on HA concentrations were analyzed by HA binding assay. 4-MU suppressed the positivity of Alcian blue staining, although this delay was reversible. Interestingly, stronger positivity of Alcian blue staining was observed at day 21 in cultures with 4-MU discontinuation than in the control. 4-MU significantly increased the mRNA expression of aggrecan, versican, and type II collagen, which was consistent with increased deposition of aggrecan and versican. The HA concentration in ECM and cell-associated region was significantly suppressed with 4-MU treatment. We conclude that the inhibition of HA synthesis slows sulfated glycosaminoglycans deposition during chondrogenic differentiation despite the increased deposition of other ECM molecules. Transient starvation of HA with 4-MU accelerates chondrogenic ECM formation, suggesting its potential to stimulate chondrogenic differentiation with adequate use.