Clinical features of patients with carcinoma soft tissue metastases as surgical indications: a retrospective cohort study

BACKGROUND

Soft-tissue metastasis of carcinoma is rare. In the present study, we investigated the surgical indications and clinical features of patients with soft tissue metastases of carcinoma.

METHODS

In this retrospective cohort study, we enrolled 26 patients with soft tissue carcinoma metastasis referred to our department for treatment. Sex, age, location, size, depth, pain due to the tumor, primary origin, serum C-reactive protein (CRP) level, MRI examinations, diagnosis by a previous physician, carcinoma markers from blood, history of carcinoma, other metastases, performance status (PS), and surgical procedures were documented. Associations between variables and surgery were statistically analyzed.

RESULTS

The primary cancer origin was found to be the lung (n = 10), kidney (n = 7), esophagus (n = 2), stomach (n = 1), breast (n = 1), liver (n = 1), ureter (n = 1), anus (n = 1), and unknown (n = 2). The mean CRP level of all patients was 2.3 mg/dL. Seven tumors (26.9%) were originally suspected to be soft tissue metastases of carcinoma, while 19 tumors (73.1%) were considered soft tissue sarcomas or inflammatory lesions by the previous treating physician. Twenty patients (76.9%) had other metastases. The PS of the 12 patients (46.2%) was zero. Eleven patients (42.3%) underwent surgery for soft tissue metastases. Diagnosis of soft tissue metastasis by a previous physician and good PS (p < 0.05) were significantly associated with surgery.

CONCLUSION

Overall, the present results show that surgical indications for soft tissue metastasis of carcinoma include diagnosis by the referring physician or good PS of the patients.

Development and validation of a nomogram to predict surgical site infection after soft-tissue sarcoma resection

Aims

Surgical site infection (SSI) after soft-tissue sarcoma (STS) resection is a serious complication. The purpose of this retrospective study was to investigate the risk factors for SSI after STS resection, and to develop a nomogram that allows patient-specific risk assessment.

Methods

A total of 547 patients with STS who underwent tumour resection between 2005 and 2021 were divided into a development cohort and a validation cohort. In the development cohort of 402 patients, the least absolute shrinkage and selection operator (LASSO) regression model was used to screen possible risk factors of SSI. To select risk factors and construct the prediction nomogram, multivariate logistic regression was used. The predictive power of the nomogram was evaluated by receiver operating curve (ROC) analysis in the validation cohort of 145 patients.

Results

LASSO regression analysis selected possible risk factors for SSI, including age, diabetes, operating time, skin graft or flap, resected tumour size, smoking, and radiation therapy. Multivariate analysis revealed that age, diabetes, smoking during the previous year, operating time, and radiation therapy were independent risk factors for SSI. A nomogram was developed based on the results of multivariate logistic regression analysis. In the development cohort, the incidence of SSI was 4.5% in the low-risk group (risk score < 6.89) and 26.6% in the high-risk group (risk score ≥ 6.89; p < 0.001). In the validation cohort, the incidence of SSI was 2.0% in the low-risk group and 15.9% in the high-risk group (p = 0.004).

Conclusion

Our nomogram will enable surgeons to assess the risk of SSI in patients with STS. In patients with high risk of SSI, frequent monitoring and aggressive interventions should be considered to prevent this.

Extensive Synergy Between Recombinant Methioninase and Eribulin Against Fibrosarcoma Cells But Not Normal Fibroblasts

BACKGROUND/AIM

The aim of the present study was to determine the synergy of recombinant methioninase (rMETase) and the anti-tubulin agent eribulin on fibrosarcoma cells, in comparison to normal fibroblasts, in vitro.

MATERIALS AND METHODS

HT1080 human fibrosarcoma cells and HS27 human fibroblasts were used for in vitro experiments. Four groups were analyzed in vitro: No-treatment control; eribulin; rMETase; eribulin plus rMETase. Dual-color HT1080 cells which express red fluorescent protein (RFP) in the cytoplasm and green fluorescent protein (GFP) in the nuclei were used to visualize cytoplasmic and nuclear dynamics during treatment.

RESULTS

Eribulin combined with rMETase greatly decreased the viability of HT 1080 cells. In contrast, eribulin combined with rMETase did not show synergy on Hs27 normal fibroblasts. Eribulin combined with rMETase also caused more fragmentation of the nucleus than all other treatments.

CONCLUSION

The combination treatment of eribulin plus rMETase demonstrated efficacy on fibrosarcoma cells in vitro. In contrast, normal fibroblasts were resistant to this combination, indicating the potential clinical applicability of the treatment.

High Clinical Concordance of Drug Resistance in Patient-derived Orthotopic Xenograft (PDOX) Mouse Models: First Step to Validated Precise Individualized Cancer Chemotherapy

Finding an effective drug for individual cancer patients among the many chemotherapies available and ruling out ineffective drugs are important challenges, especially for patients with advanced cancer. To accomplish this goal, we have pioneered and developed the patient-derived orthotopic xenograft (PDOX) nude mouse model for all cancer types, enabling the discovery and evaluation of novel therapeutics, as well as individualized therapy of patients with cancer. PDOX models can more precisely reproduce the original tumor microenvironment (TME) compared to subcutaneous-implanted xenografts including patient-derived xenograft (PDX) models. The present review presents the concordance of drug resistance in individual cancer patients and their PDOX models. There are 28 PDOX publications with 12 PDOX models from patients who were treated with chemotherapy. Sixteen chemotherapeutics were administrated to these patients and all of them were clinically ineffective. In PDOX models established from these patients' tumors, fourteen chemotherapeutics were resistant with a concordance rate of 88%. PDOX models should be established as early as possible from patients to predict and improve outcome. PDOX models mimic the clinical tumor aggressiveness, therefore enabling a high concordance with clinical outcomes. The present review shows a high concordance for drug resistance between cancer patients and their corresponding PDOX models. Future studies will include prospective clinical trials comparing both drug efficacy and resistance in patients and their PDOX models.

Case Report: Unresectable pulmonary metastases of a giant cell tumor of bone treated with denosumab: a case report and review of literature

Giant cell tumors of bone (GCTB) sometimes metastasize to distant organs. In this case report, we present pulmonary metastases of GCTB mimicking malignancies. A 49-year-old man underwent two surgical treatments for a GCTB of the right proximal radius. At the time of the second surgery, no lesions were observed on chest radiography. Three years after surgery, the patient presented with cough and dyspnea, and chest radiography and computed tomography (CT) revealed multiple lung nodules. Positron emission tomography/CT revealed a high accumulation of 18F-fluoro-2-deoxy-D-glucose (18F-FDG) in multiple lesions. Based on the rapid growth and accumulation of 18F-FDG, a metastatic malignant tumor was suspected. CT-guided needle biopsy was performed, and the histology showed proliferation of spindle cells and multinuclear giant cells without malignant changes. Denosumab was administered because multiple lung lesions were unresectable. One month after denosumab treatment, CT showed marked shrinkage of the lesions, and the symptoms significantly improved. Eighteen months after the initial treatment with denosumab, the patient had no symptoms or tumor growth. Although its long-term efficacy and safety remain unclear, denosumab may be a treatment option for patients with unresectable pulmonary GCTB.

Graft Survivals after Reconstruction Using Tumor-Bearing Frozen Bone in the Extremities

Tumor-bearing frozen autografts have been widely used for reconstruction of bone defects caused by tumor resection. However, some patients undergo removal of the grafted bone due to surgical site infection, tumor recurrence, or fractures of the grafted bone. In this retrospective cohort study, predictive factors for graft survival were investigated in 123 patients who underwent reconstructions using a tumor-bearing frozen autograft after bone tumor resection of the extremities. To determine the independent predictors of graft survival, the association between various parameters and graft survival was investigated. The graft survival rates were 83.2% at 5 years and 70.2% at 10 years. Among the 123 frozen autografts, 25 (20.3%) were removed because of complications. In univariate analyses, male sex, BMI of ≥23.6, tibia, and chemotherapy were significantly associated with poor graft survival, whereas the pedicle/hemicortical freezing procedure was significantly associated with better graft survival. Multivariate analysis using the Cox proportional hazards regression model revealed that BMI of ≥23.6 (HR, 3.4; p = 0.005), tibia (HR, 2.3; p = 0.047), and freezing procedure (HR, 0.3; p = 0.016) were independently associated with graft survival. Based on the results, pedicle or hemicortical freezing techniques are recommended in cases where these techniques can be applied.

Needle tract seeding of a sclerosing epithelioid fibrosarcoma in a biopsy tract: a case report

BACKGROUND

A sclerosing epithelioid fibrosarcoma (SEF) is an uncommon tumor of the deep soft tissue. An SEF has been described as a low-grade tumor with high local recurrence and metastatic rates. Generally, in bone and soft tissue tumors, a resection of the biopsy route is recommended; however, there is limited evidence with respect to the dissemination of the tumor tissue during a needle biopsy.

CASE PRESENTATION

A mass in the right pelvic cavity, with no symptoms, was observed in a 45-year-old woman during a gynecological examination. Computed tomography (CT) revealed a multilocular mass with calcification in the pelvic cavity. The magnetic resonance imaging (MRI) showed an iso-signal intensity on T1 weighted images and hypo- and iso-signal intensity on T2 weighted images. The CT-guided core needle biopsy was performed using a dorsal approach, and the biopsy diagnosis was a low-grade spindle cell tumor. The tumor was excised using an anterior approach. The tumor tissue comprised spindle cells and epithelioid cells with irregular nuclei, and the immunohistological analysis was positive for vimentin and epithelial membrane antigen, which was consistent with a diagnosis of sclerosing epithelioid fibrosarcoma. Five years after the surgery, the MRI showed a tumor recurrence in the subcutaneous tissue of the right buttock, which was consistent with the needle biopsy tract. The patient underwent a tumor excision, and the resected tumor was similar to the primary tumor.

CONCLUSIONS

The recurrent tumor was excised with a surgical margin, and the tumor specimen had the histological features of a sclerosing epithelioid fibrosarcoma. It was difficult to investigate the association of the core needle biopsy with the tumor recurrence because the approach of the biopsy tract is usually same as that used in a tumor excision. However, the present case indicated the tumor may recur in the biopsy tract of a soft tissue sarcoma. Surgeons should be aware of the possibility of disseminating tumor tissues in a needle biopsy.

Colon-cancer liver metastasis is effectively targeted by recombinant methioninase (rMETase) in an orthotopic mouse model

BACKGROUND

Colorectal cancer liver metastasis (CCLM) is the most frequent cause of death of colorectal cancer. Development of novel new effective therapy is needed for CCLM patients to improve outcome. The aim of the present study was to investigate the efficacy of recombinant methioninase (rMETase) on a CCLM orthotopic mouse model of liver metastasis established using the human colon cancer cell line HT29 expressing red fluorescent protein (RFP).

MATERIALS AND METHODS

Orthotopic CCLM nude mouse models were randomized into two groups: control group (n = 6, PBS 200 µl, i.p., daily); rMETase group (n = 6, 100 units/200 µl, i.p., daily). Tumor volume was measured on day 0 and day 15. Body weight was measured twice a week. All mice were sacrificed on day 15.

RESULTS

rMETase significantly inhibited the increase of the liver metastasis as determined by RFP fluorescence area and intensity (p = 0.016 and 0.015, respectively). There was no significant difference of body weight between either group on any day.

CONCLUSIONS

The present study suggests that rMETase has future potential therapy for CCLM in the clinic.

A validation study for the utility of serum microRNA as a diagnostic and prognostic marker in patients with osteosarcoma

In our previous study, osteosarcoma advanced locally, and metastasis was promoted through the secretion of large number of small extracellular vesicles, followed by suppressing osteoclastogenesis via the upregulation of microRNA (miR)-146a-5p. An additional 12 miRNAs in small extracellular vesicles were also detected ≥6× as frequently in high-grade malignancy with the capacity to metastasize as in those with a low metastatic potential. However, the utility of these 13 miRNAs for determining the prognosis or diagnosis of osteosarcoma has not been validated in the clinical setting. In the present study, the utility of these miRNAs as prognostic and diagnostic markers was therefore assessed. In total, 30 patients with osteosarcoma were retrospectively reviewed, and the survival rate was compared according to the serum miRNA levels in 27 patients treated with chemotherapy and surgery. In addition, to confirm diagnostic competency for osteosarcoma, the serum miRNA levels were compared with those in patients with other bone tumors (n=112) and healthy controls (n=275). The patients with osteosarcoma with high serum levels of several miRNAs (miR-146a-5p, miR-1260a, miR-487b-3p, miR-1260b and miR-4758-3p) exhibited an improved survival rate compared with those with low levels. In particular, patients with high serum levels of miR-1260a exhibited a significantly improved overall survival rate, metastasis-free survival rate and disease-free survival rate compared with those with low levels. Thus, serum miR-1260a may potentially be a prognostic marker for patients with osteosarcoma. Moreover, patients with osteosarcoma had higher serum miR-1261 levels than those with benign or intermediate-grade bone tumors and thus may be a potential therapeutic target, in addition to being useful for differentiating whether or not a bone tumor is high-grade. A larger investigation is required to clarify the actual utility of these miRNAs in the clinical setting.

Clinical Benefits of LigaSure™ for Surgical Amputation Without Tourniquet Use in Patients With Musculoskeletal Tumor

BACKGROUND/AIM

Amputation is still a viable option for musculoskeletal tumors that are multi-compartmental, adjacent to neurovascular structures, and involving pathological fractures. Complications such as poor surgical margins, local recurrence and infection after limb salvage surgery are also indications for secondary amputation. An effective hemostatic technique is vital for preventing complications of massive blood loss and prolonged operative time. The use of LigaSure™ in the field of musculoskeletal oncology has not been well documented.

PATIENTS AND METHODS

This retrospective study included 27 patients with musculoskeletal tumor who underwent amputation using either LigaSure™ system (n=12) or traditional hemostatic technique (n=15) from 1999 to 2020. The purpose of this study was to evaluate the effect of LigaSure™ in terms of intra-operative blood loss, blood transfusion rates, and duration of surgery.

RESULTS

The use of LigaSure™ resulted in a significant decrease in intraoperative blood loss (p=0.027) and blood transfusion rates (p=0.020). There was no significant difference for the duration of surgery between the two groups (p=0.634).

CONCLUSION

The LigaSure™ system can potentially improve clinical outcomes in patients with musculoskeletal tumor undergoing amputation surgeries. The LigaSure™ system is a safe and effective hemostatic tool for musculoskeletal tumor amputation surgeries.

Kimura's Disease Diagnosed in the Department of Orthopedic Surgery Treated With Wide Excision: Report of Two Cases

BACKGROUND/AIM

Kimura's disease is a rare chronic inflammatory disorder that commonly affects the head and neck regions, occurring predominantly in Asian men. Elevated eosinophil count and IgE levels in the peripheral blood examination are suggestive of this disease. In this study we report two cases of Kimura's disease, treated with wide excision.

CASE REPORT

The first case was a 58-year-old man presented with asymptomatic left neck mass. The second case was a 69-year-old man with swelling of the right upper arm, which was suggestive of soft tissue mass. Needle biopsy results were suggestive of Kimura's disease in both cases. Elevated WBCs at 8,380/μl (neutrophils: 45%, eosinophils: 33%) for the first case and 5,370/μl (neutrophils: 61.8%, eosinophils: 3.5%) for the second one, and serum IgE at 14.988 IU/ml for the first case and 1,315 IU/ml for the second one were observ. For definitive treatment and diagnosis, wide excisions were performed. Final histopathological results revealed Kimura's disease. Surgical margins were negative even though an ill-demarcated lesion for the first case and high infiltration to the muscle for second case were confirmed.

CONCLUSION

Wide excision was performed in both cases of Kimura's disease and no recurrence was observed until the final follow-up. Wide excision with negative surgical margin should be recommended for the treatment of Kimura's disease.

Antibacterial effect and biological reaction of calcium phosphate cement impregnated with iodine for use in bone defects

Calcium phosphate cement (CPC) is often used to repair bone defects that occur after bone tumor and fracture treatment. To address bone defect cases with a high infection risk, developing CPCs with a longlasting wide-spectrum antibacterial effect is critical. Povidone-iodine has a wide antibacterial spectrum. Though there have been some reports of CPC containing antibiotics, no report of CPC with iodine has been described. In this study, the antibacterial effect and biological reaction of CPC impregnated with iodine was investigated. Iodine release from CPC and bone cement with various iodine contents (2.5, 5, and 20%) was evaluated, and 5 %-iodine CPC retained more iodine than the other CPCs after one week. Antibacterial activity against Staphylococcus aureus and Escherichia coli was also investigated, showing that 5 %-iodine had an antibacterial effect for up to eight weeks. Cytocompatibility was assessed, and 5 %-iodine CPC showed the same amount of fibroblast colony formation as control samples. CPCs with varying iodine contents (0, 5, and 20%) were then inserted into lateral femora of Japanese white rabbits for histological analysis. Osteoconductivity was evaluated using scanning electron microscopy, and hematoxylin-eosin staining. Consecutive bone formation was observed around all CPCs at eight weeks. These results indicate that CPC impregnated with iodine exhibits antimicrobial activity and cytocompatibility, and therefore, it may be effective for bone defect cases with high infection risk.

Novel predictors of immune checkpoint inhibitor response and prognosis in advanced non-small-cell lung cancer with bone metastasis

BACKGROUNDS

Immune checkpoint inhibitors (ICIs) can significantly prolong the survival of patients with advanced non-small-cell lung cancer (NSCLC); however, few studies on the therapeutic effects of ICIs on bone metastases were performed.

METHODS

This retrospective study aimed to investigate the therapeutic effects of ICIs and determine predictors of favorable ICI response and prognosis in 55 advanced NSCLC patients with bone metastases who initiated ICI treatment between 2016 and 2019, with a mean follow-up period of 23.2 months. Patients were classified into responders (complete or partial response) and non-responders (stable or progressive disease) according to the MD Anderson Cancer Center (MDA) criteria, and the predictors of therapeutic response were identified using multivariate logistic regression analysis. Furthermore, overall survival from the time of ICI administration to the final follow-up or death was evaluated, and prognostic predictors were identified using Cox proportional hazards regression analysis.

RESULTS

ICI response rate was 30.9% (complete in three cases, partial in 14). Median survival time was 9.3 months, with 1-year and 2-year survival rates of 40.6% and 19.3%, respectively. Responders survived significantly longer than non-responders (p = 0.03). Based on the receiver operating characteristic curve, the predictive cutoff value of the pretreatment neutrophil-to-lymphocyte ratio (NLR) was 2.1. Multivariate analysis identified female sex (p = 0.03), use of ICIs as first-line therapy (p < 0.01), and NLR <2.1 (p = 0.03) as significant predictors of therapeutic response, whereas concomitant use of a bone-modifying agent (p < 0.01), Katagiri score ≤6 points (p < 0.01), and NLR <2.1 (p = 0.02) were identified as significant predictors of good prognosis.

CONCLUSIONS

This study identified some novel predictors for favorable therapeutic response and prognosis in advanced NSCLC patients with bone metastases undergoing ICI treatment. Pretreatment NLR less than 2.1 can be considered the most important predictor.

Heat-killed Lactobacillus helveticus improves mood states: a randomised, double-blind, placebo-controlled study

We investigated the effects of heat-killed Lactobacillus helveticus MCC1848 on daily mood states in healthy young adults. Participants (n=58) were randomised to receive heat-killed L. helveticus MCC1848 powder or placebo powder for 4 weeks. During the study period, adverse events were recorded in the participant diary. Mood states were assessed before and 2 and 4 weeks after initiation of the intervention. The primary outcomes were the shortened version of the Profile of Mood States 2 (POMS 2) scores. Secondary outcomes included other mood state (State-Trait Anxiety Inventory (STAI); visual analogue scale (VAS)), quality of life (acute form of the SF-36v2), sleep (Athens Insomnia Scale (AIS)) and fatigue (Chalder Fatigue Scale (CFS)) scores. Four weeks of heat-killed L. helveticus MCC1848 intake, compared to placebo, significantly improved the shortened version of the POMS 2 'friendliness' and the VAS 'relaxed' scores, which are two indicators of positive mood states. On the other hand, heat-killed L. helveticus MCC1848 intake had no significant effects on negative mood state items (e.g. anger, nervousness, confusion) assessed by the shortened version of the POMS 2, STAI and VAS. AIS and CFS scores also showed no significant differences. No adverse effects were observed with 4 weeks of heat-killed L. helveticus MCC1848 intake. These results suggest that daily consumption of heat-killed L. helveticus MCC1848 is safe and has the potential to improve positive mood states. UMIN Clinical Trial Registry: UMIN000043697.

Synergy of oral recombinant methioninase (rMETase) and 5-fluorouracil on poorly differentiated gastric cancer

Gastric cancer is highly malignant and recalcitrant to first line chemotherapies that include 5-fluorouracil (5-FU). Cancer cells are addicted to methionine for their proliferation and survival. Methionine addiction of cancer is known as the Hoffman effect. Methionine restriction with recombinant methioninase (rMETase) has been shown to selectively starve cancer cells and has shown synergy with cytotoxic chemotherapy including 5-FU. The present study aimed to investigate the efficacy of rMETase alone and the combination with 5-FU on poorly differentiated human gastric cancer cell lines (MKN45, NUGC3, and NUGC4) in vitro and vivo. rMETase suppressed the tumor growth of 3 kinds of poorly differentiated gastric cancer cells in vitro. The fluorescence ubiquitination-based cell cycle indicator (FUCCI) demonstrated cancer cells treated with rMETase were selectively trapped in the S/G₂ phase of the cell cycle. In the present study, subcutaneous MKN45 gastric cancer models were randomized into four groups when the tumor volume reached 100 mm³: G1: untreated control; G2: 5-FU (i.p., 50 mg/kg, weekly, three weeks); G3: oral-rMETase (o-rMETase) (p.o., 100 units/body, daily, three weeks); G4: 5-FU with o-rMETase (5-FU; i.p., 50 mg/kg, weekly, three weeks o-rMETase; p.o., 100 units/body, daily, three weeks). All mice were sacrificed on day 22. Body weight and estimated tumor volume were measured twice a week. 5-FU and o-rMETase suppressed tumor growth as monotherapies on day 18 (p = 0.044 and p = 0.044). However, 5-FU combined with o-rMETase was significantly superior to each monotherapy (p < 0.001 and p < 0.001, respectively) and induced extensive necrosis compared to other groups. The combination of 5-FU and o-rMETase shows promise for transformative therapy for poorly differentiated gastric cancer in the clinic.

A Viability Analysis of Tumor-Bearing Frozen Autograft for the Reconstruction After Resection of Malignant Bone Tumors Using 99m Tc-MDP Scintigraphy

PURPOSE OF THE REPORT

Several methods are used to reconstruct bony defects after malignant tumor excision. Tumor-bearing frozen autograft reconstruction is a biological procedure in which tumor-bearing bone is reused after devitalization with liquid nitrogen to kill tumor cells. The viability of frozen autografts has not been fully evaluated over time. We therefore aimed to evaluate the viability of devitalized bone grafts, using 99m Tc-MDP scintigraphy.

PATIENTS AND METHODS

Seventy-four patients who underwent frozen autograft reconstruction after the excision of a malignant bone tumor were enrolled. Two hundred forty-two postoperative 99m Tc-MDP scans were reviewed. For a quantitative analysis, the region of interest on the frozen bone segment and a symmetric region of interest on the contralateral normal area were manually set. The radioactive tracer uptake ratio was calculated by dividing the count density of the frozen bone segment by that of the contralateral normal area in each image. An uptake ratio of 0.9 to 1.1 was defined as a normalization of tracer uptake.

RESULTS

Normalization of tracer uptake was achieved in 95% to 97% of the cases by 60 months postoperatively, and earlier in the middle zone and peripheral zone in the pedicle freezing group in comparison to the free freezing group (both P = 0.03). Fracture and nonunion was associated with a low uptake ratio, whereas infection was associated with a high uptake ratio before the occurrence of the event.

CONCLUSIONS

The calculation of the uptake ratio using 99m Tc-MDP scans was an objective and accurate evaluation method. The period to normalization of tracer uptake in the pedicle frozen bone was significantly earlier than that in the free frozen bone. The postoperative complications can be also predicted.

Do Liquid Nitrogen-treated Tumor-bearing Nerve Grafts Have the Capacity to Regenerate, and Do They Pose a Risk of Local Recurrence? A Study in Rats

BACKGROUND

Under most circumstances, the resection of soft tissue sarcomas of the extremities can be limb-sparing, function-preserving oncologic resections with adequate margins. However, en bloc resection may require resection of the major peripheral nerves, causing poor function in the extremities. Although liquid nitrogen treatment has been used to sterilize malignant bone tumors, its use in the preparation of nerve grafts has, to our knowledge, not been reported. Hence, this study aimed to investigate the tumor recurrence and function after peripheral nerve reconstruction using liquid nitrogen-treated tumor-bearing nerves in a rat model.

QUESTIONS/PURPOSES

(1) Do liquid nitrogen-treated frozen autografts have regeneration capabilities? (2) Do liquid nitrogen-treated tumor-bearing nerves cause any local recurrences in vivo in a rat model?

METHODS

Experiment 1: Twelve-week-old female Wistar rats, each weighing 250 g to 300 g, were used. A 10-mm-long section of the right sciatic nerve was excised; the prepared nerve grafts were bridge-grafted through end-to-end suturing. The rats were grouped as follows: an autograft group, which underwent placement of a resected sciatic nerve after it was sutured in the reverse orientation, and a frozen autograft group, which underwent bridging of the nerve gap using a frozen autograft. The autograft was frozen in liquid nitrogen, thawed at room temperature, and then thawed in distilled water before application. The third group was a resection group in which the nerve gap was not reconstructed. Twenty-four rats were included in each group, and six rats per group were evaluated at 4, 12, 24, and 48 weeks postoperatively. To assess nerve regeneration after reconstruction using the frozen nerve graft in the nontumor rat model, we evaluated the sciatic functional index, tibialis anterior muscle wet weight ratio, electrophysiologic parameters (amplitude and latency), muscle fiber size (determined with Masson trichrome staining), lower limb muscle volume, and immunohistochemical findings (though neurofilament staining and S100 protein produced solely and uniformly by Schwann cells associated with axons). Lower limb muscle volume was calculated via CT before surgery (0 weeks) and at 4, 8, 12, 16, 20, 24, 32, 40, and 48 weeks after surgery. Experiment 2: Ten-week-old female nude rats (F344/NJcl-rnu/rnu rats), each weighing 100 g to 150 g, were injected with HT1080 (human fibrosarcoma) cells near the bilateral sciatic nerves. Two weeks after injection, the tumor grew to a 10-mm-diameter mass involving the sciatic nerves. Subsequently, the tumor was resected with the sciatic nerves, and tumor-bearing sciatic nerves were obtained. After liquid nitrogen treatment, the frozen tumor-bearing nerve graft was trimmed to a 5-mm-long tissue and implanted into another F344/NJcl-rnu/rnu rat, in which a 5-mm-long section of the sciatic nerve was resected to create a nerve gap. Experiment 2 was performed with 12 rats; six rats were evaluated at 24 and 48 weeks postoperatively. To assess nerve regeneration and tumor recurrence after nerve reconstruction using frozen tumor-bearing nerve grafts obtained from the nude rat with human fibrosarcoma involving the sciatic nerve, the sciatic nerve's function and histologic findings were evaluated in the same way as in Experiment 1.

RESULTS

Experiment 1: The lower limb muscle volume decreased once at 4 weeks in the autograft and frozen autograft groups and gradually increased thereafter. The tibialis anterior muscle wet weight ratio, sciatic functional index, muscle fiber size, and electrophysiologic evaluation showed higher nerve regeneration potential in the autograft and frozen autograft groups than in the resection group. The median S100-positive areas (interquartile range [IQR]) in the autograft group were larger than those in the frozen autograft group at 12 weeks (0.83 [IQR 0.78 to 0.88] versus 0.57 [IQR 0.53 to 0.61], difference of medians 0.26; p = 0.04) and at 48 weeks (0.86 [IQR 0.83 to 0.99] versus 0.74 [IQR 0.69 to 0.81], difference of median 0.12; p = 0.03). Experiment 2: Lower limb muscle volume decreased at 4 weeks and gradually increased thereafter. The median muscle fiber size increased from 0.89 (IQR 0.75 to 0.90) at 24 weeks to 1.20 (IQR 1.08 to 1.34) at 48 weeks (difference of median 0.31; p< 0.01). The median amplitude increased from 0.60 (IQR 0.56 to 0.67) at 24 weeks to 0.81 (IQR 0.76 to 0.90) at 48 weeks (difference of median 0.21; p < 0.01). Despite tumor involvement and freezing treatment, tumor-bearing frozen grafts demonstrated nerve regeneration activity, with no local recurrence observed at 48 weeks postoperatively in nude rats.

CONCLUSION

Tumor-bearing frozen nerve grafts demonstrated nerve regeneration activity, and there was no tumor recurrence in rats in vivo.

CLINICAL RELEVANCE

A frozen nerve autograft has a similar regenerative potential to that of a nerve autograft. Although the findings in a rat model do not guarantee efficacy in humans, if they are substantiated by large-animal models, clinical trials will be needed to evaluate the efficacy of tumor-bearing frozen nerve grafts in humans.

Impact of number of functional teeth on independence of Japanese older adults

AIM

To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence.

METHODS

Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed.

RESULTS

This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant.

CONCLUSIONS

The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.

Insufficiency fracture of the supra-acetabulum that required differentiation from a pathological fracture secondary to a malignant bone tumor: a case report

Background

The supra-acetabulum is a common site for malignant bone tumors, which can be difficult to differentiate from insufficiency fractures. We report a rare case of a stress fracture of the supra-acetabulum that required differentiation from a malignant bone tumor.

Case presentation

A 74-year-old Japanese man presented to the hospital because of right hip joint pain. X-rays showed no obvious abnormalities. Magnetic resonance imaging showed an abnormality in the right supra-acetabulum, and he was referred to our department. A linear, low-signal region and its surrounding equal signal region were observed at the same site in the T1-weighted image, and a linear low-signal region and high signal region were observed in the surrounding area in the T2-weighted image. On the contrast-enhanced magnetic resonance imaging, the lesion was still unclear and the whole area was gradually enhanced. A computed tomography-guided needle biopsy was performed, but no tumor cells were observed, therefore the lesion was presumed to be a fracture healing. The bone density was 66% for the lumbar spine (young adult mean, L2–4), and blood biochemistry showed an increase in alkaline phosphatase and total type I procollagen N-terminal propeptide.

Conclusion

This case was diagnosed as an insufficiency fracture of the supra-acetabulum in a male patient with primary osteoporosis by biopsy specimen. Initially, a pathological fracture associated with a malignant lesion was considered. On magnetic resonance imaging, the boundary around the fracture line was unclear and a signal change that was gradually enhanced by gadolinium was observed. This is likely to be bone marrow edema associated with the stress fracture, and we believe this to be a useful finding that may help in differentiating a stress fracture from a pathological fracture secondary to a malignant lesion.

Case report: Complete remission of bone metastasis from renal cell carcinoma in histopathological examination after treatment with immune checkpoint inhibitors

Recently, the prognosis of metastatic renal cell carcinoma (mRCC) has improved owing to the development of immunotherapy using immune checkpoint inhibitors (ICIs). However, there have been few studies on the therapeutic effect of ICIs in bone metastases from renal cell carcinoma (RCC). We report a case in which pulmonary and humeral metastases from RCC were significantly ameliorated using ICIs, while surgery for a pathological fracture of the humerus significantly improved the patient’s quality of life (QoL). A 70-year-old man who underwent a left nephrectomy for RCC developed multiple pulmonary metastases and humeral metastasis with a pathological fracture one year after surgery, and combined treatment with nivolumab and ipilimumab was initiated. After four courses of ICI treatment, multiple pulmonary metastases had almost disappeared, and the tumor at the fracture site had shrunk remarkably. However, the shoulder joint function had decreased due to the fracture, worsening his QoL. Therefore, he underwent surgery and returned to normal daily life one month after. Postoperative histopathological examination of bone and soft tissue at the fracture site revealed no malignancy. To our knowledge, this is the first case report of complete remission of bone metastasis of RCC based on histopathological examination with ICI treatment.

Randomized placebo-controlled double-blind phase II study of zaltoprofen for patients with diffuse-type and unresectable localized tenosynovial giant cell tumors: The REALIZE study

Background

A tenosynovial giant cell tumor (TGCT) is a locally aggressive benign neoplasm arising from intra- or extra-articular tissue, categorized as localized (L-TGCT, solitary lesion) and diffuse (D-TGCT, multiple lesions) TGCT. Surgical excision is the mainstay of the treatment, and a high local recurrence rate of approximately 50% has been reported. We focused on zaltoprofen, a nonsteroidal anti-inflammatory drug that can activate peroxisome proliferator-activated receptor gamma (PPARγ) and inhibit the proliferation of TGCT stromal cells. Therefore, we conducted a randomized trial to evaluate the safety and effectiveness of zaltoprofen in patients with D-TGCTs or unresectable L-TGCTs.

Methods

This randomized, placebo-controlled, double-blind, multicenter trial evaluated the safety and efficacy of zaltoprofen. In the treatment group, zaltoprofen (480 mg/day) was administered for 48 weeks; the placebo group received similar dosages without zaltoprofen. The primary outcome was progression-free rate (PFR) 48 weeks after treatment administration. Disease progression was defined as the following conditions requiring surgical intervention: 1) repetitive joint swelling due to hemorrhage, 2) joint range of motion limitation, 3) invasion of the adjacent cartilage or bone, 4) severe joint space narrowing, and 5) increased tumor size (target lesion).

Results

Forty-one patients were allocated to the zaltoprofen (n=21) or placebo (n=20) groups. The PFR was not significant between the zaltoprofen group and the placebo group at 48 weeks (84.0% and 90.0%, respectively; p=0.619). The mean Japanese Orthopedic Association knee score significantly improved from baseline to week 48 in the zaltoprofen group (85.38 versus 93.75, p=0.027). There was a significant difference between the values at 48 weeks of placebo and zaltoprofen group (p=0.014). One severe adverse event (grade 3 hypertension) was observed in the zaltoprofen group.

Discussion

This is the first study to evaluate the efficacy and safety of zaltoprofen in patients with TGCT. No significant differences in PFR were observed between the groups at 48 weeks. Physical function significantly improved after zaltoprofen treatment. The safety profile of zaltoprofen was acceptable. This less invasive and safer treatment with zaltoprofen, compared to surgical removal, could be justified as a novel approach to treating TGCT. Further analysis of long-term administration of zaltoprofen should be considered in future studies.

Clinical Trial Registration

University Hospital Medical Information Network Clinical Trials Registry, identifier (UMIN000025901).

Surgical Site Infection after Bone Tumor Surgery: Risk Factors and New Preventive Techniques

The management of malignant bone tumors requires multidisciplinary interventions including chemotherapy, radiation therapy, and surgical tumor resection and reconstruction. Surgical site infection (SSI) is a serious complication in the treatment of malignant bone tumors. Compared to other orthopedic surgeries, the surgical treatment of malignant bone tumors is associated with higher rates of SSIs. In patients with SSIs, additional surgeries, long-term administrations of antibiotics, extended hospital stays, and the postponement of scheduled adjuvant treatments are required. Therefore, SSI may adversely affect functional and oncological outcomes. To improve surgical outcomes in patients with malignant bone tumors, preoperative risk assessments for SSIs, new preventive techniques against SSIs, and the optimal use of prophylactic antibiotics are often required. Previous reports have demonstrated that age, tumor site (pelvis and tibia), extended operative time, implant use, body mass index, leukocytopenia, and reconstruction procedures are associated with an increased risk for SSIs. Furthermore, prophylactic techniques, such as silver and iodine coatings on implants, have been developed and proven to be efficacious and safe in clinical studies. In this review, predictive factors of SSIs and new prophylactic techniques are discussed.

Review: Precise sarcoma patient-derived orthotopic xenograft (PDOX) mouse models enable identification of novel effective combination therapies with the cyclin-dependent kinase inhibitor palbociclib: A strategy for clinical application

Introduction

Sarcomas are rare heterogeneous malignant tumors that originate and develop in soft tissue or bone. Effective treatment for sarcomas is still limited to traditional chemotherapy and surgery that are often ineffective for recurrent disease. Cyclin-dependent kinases (CDKs) promote abnormal cell cycling and cell division in many cancers including sarcomas. Therefore, our hypothesis was that CDK inhibitors may be useful candidates for sarcoma treatment. Patient-derived orthotopic xenograft (PDOX) mouse models mimic the clinical disease for all major cancer types and have identified effective treatments that hold much clinical promise. The present report reviews sarcoma PDOX models that we have established for their potential to discover effective combination treatments based on CDK inhibitors for recalcitrant sarcoma.

Methods

We have previously reported six sarcoma PDOX studies evaluating the CDK inhibitor palbociclib on sarcoma, including osteosarcoma, Ewing sarcoma, de-differentiated liposarcoma, and peritoneal metastatic leiomyosarcoma.

Results

Palbociclib monotherapy significantly inhibited, but not regressed, the PDOX growth of osteosarcoma, Ewing sarcoma, de-differentiated liposarcoma, and peritoneal metastatic leiomyosarcoma. A combination of palbociclib and a mammalian target of rapamycin (mTOR) inhibitor, everolimus, significantly inhibited, but did not regress, the PDOX growth of osteosarcoma. Combinations of palbociclib with a multikinase inhibitor, sorafenib, and palbociclib combined with recombinant methioninase were effective and regressed the osteosarcoma and de-differentiated liposarcoma PDOX models, respectively.

Conclusions

Novel effective drug combinations using the CDK inhibitor palbociclib were identified in PDOX models of the major types of sarcomas. Methionine restriction effected by methioninase increased the efficacy of palbociclib. Combination therapy with palbociclib is a promising future strategy for improved sarcoma therapy in the clinic.

Novel predictors associated with therapeutic effects of immune checkpoint inhibitors on bone metastasis of non-small cell lung cancer

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Background: In recent years, immune checkpoint inhibitors (ICIs) have brought dramatic therapeutic effects on lung cancer. However, there are few reports regarding the therapeutic effect of ICIs on bone metastasis of non-small cell lung cancer (NSCLC). The purpose of this study was to investigate the therapeutic effects of ICIs on bone metastases of NSCLC and to analyze the predictors associated with ICI's response to them. Methods: This retrospective study analyzed NSCLC with bone metastases who initiated ICI treatment between 2016 and 2019. Clinical data was investigated and used as variables for analyzing the therapeutic effect predictors of ICIs. Blood sampling data were used within 1 week before ICI treatment initiation. The therapeutic effect of ICIs on bone metastases was evaluated by MD Anderson criteria (MDA criteria), and overall survival (OS) after the initiation of ICI treatment was investigated. Based on the evaluation of MDA criteria, univariate analysis was performed between the response group (CR+PR) and non-response group (SD+PD), and variables with p < 0.05 were used for multivariate logistic regression analysis to investigate the predictors associated with the therapeutic effect of ICIs. Results: The 55 patients were included comprising 40 males and 15 females (mean age of 66.3±7.9 years) and the mean follow-up period was 23.2 months. The response rate of ICIs to bone metastasis was 30.9% including 3 cases in CR and 14 cases in PR. The median survival time was 9.3 months, and the 1-year and 2-year survival rates were 40.6% and 19.3%, respectively. The OS was significantly longer in the response group than in the non-response group (p < 0.01). In the blood sampling data, the cutoff value of neutrophil-to-lymphocyte ratio (NLR) determined by receiver operating characteristic (ROC) curve analysis was 2.1. The multivariate analysis based on the variables with p < 0.05 in the univariate analysis revealed significant differences in sex, treatment line of ICIs, and NLR (Table). Conclusions: Treatment with ICIs showed favorable responses to bone metastasis and better prognosis in advanced NSCLC. Moreover, this study revealed that “female, NLR < 2.1, and first-line treatment of ICIs” were independent predictors associated with favorable response to bone metastasis.[Table: see text]

Compartment-specific Clinical Outcomes in Patients With Soft Tissue Sarcomas of the Thigh

BACKGROUND/AIM

The thigh is divided into the anterior, medial, and posterior compartments, and malignant soft tissue tumours can occur in any compartment of the thigh. This study analysed the relationship between various factors, particularly tumour location and clinical outcome, in patients with primary soft tissue sarcoma of the thigh.

PATIENTS AND METHODS

Seventy-four patients were included in this retrospective study. The relationships between variables and prognosis were statistically analysed.

RESULTS

Multivariate analysis of the patient clinical data demonstrated that seromas developed more often in the medial compartment tumours and postoperative complications excluding seroma occurred more frequently in patients with two or more muscles resected or stage III tumours. A low Musculoskeletal Tumor Society score was associated with a long operative time (more than 120 min), anterior compartment tumours, and more than two muscle resections. In addition, soft tissue sarcomas in the medial compartment and stage III sarcomas were associated with a low 5-year metastasis-free survival.

CONCLUSION

Soft tissue sarcomas in the medial compartment were associated with postoperative seroma and metastasis, whereas sarcomas in the anterior compartment correlated with low postoperative function.

Clinical outcomes and life expectancy of patients with unplanned excisions of soft tissue sarcoma

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Background: As soft tissue sarcomas are rare, it is not uncommon that soft tissue sarcoma excision is performed without the required preoperative imaging, staging, or wide resection margins for sarcomas. This study investigated the characteristics of unplanned excision and analyzed the recurrence, life expectancy, and proper treatment for unplanned excision. Methods: Patients who underwent unplanned excision at another institution followed by additional wide excision at our hospital from January 2002 to December 2018 were identified. Forty-two patients met our criteria. The relationships between variables and oncological outcomes were statistically analyzed. Results: The mean age was 57.3 years (15–85 years). Sixty-nine percent (29 in 42) of tumors was in the subcutaneous tissue. Six tumors were located in the upper extremity, 24 in the lower extremity, and 12 in the trunk. Surgical margin after additional wide excision was positive in 10 cases and negative in 32 cases. Pathological examination of specimen showed 34 of 42 cases (80.9%) had residual tumor after primary tumor excision. Fourteen patients (33.3%) required reconstructions. Of the 42 patients, one had both preoperative MRI and biopsy, while nine patients underwent MRI only. Among them, only one patient had enhanced MRI. Ten patients had chemotherapy while no patient had radiotherapy over the follow-up period. The mean tumor size was 5.3 cm (0.8-20 cm). The unplanned excisions were performed by orthopaedic surgeons in 18 cases, by general surgeons in eight, by plastic surgeons in seven, by other surgeons in four. Four primary surgeries (9.5%) were performed in a sarcoma center. On multivariate analysis, positive surgical margin (HR 4.04, 95% CI 1.57-10.4, p < 0.01) was significantly associated with lower 5-year recurrence-free survival. Conclusions: First, to reduce the number of cases of unplanned excision, it should be recognized that small, subcutaneous tumors may be malignant. Second, it is considered that the high recurrence rate with positive margins after additional wide excision might be due to failure to recognize the nature and extent of the tumor without enhanced MRI and biopsy before primary surgery. Finally, surgeons should be aware that positive margin at additional wide excision is an independent risk factor for local recurrence.[Table: see text]

Compartment-specific clinical outcomes in patients with soft tissue sarcomas of the thigh

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Background: Approximately one-third of all soft tissue sarcomas develop in the thigh, and the risk factors for developing a complication after soft tissue sarcoma resection include the tumour’s location in the lower extremity. This study analysed the relationship between various factors, particularly tumour location and clinical outcome, in patients with primary soft tissue sarcoma of the thigh. Methods: Patients who underwent wide excision of soft tissue sarcomas of the thigh without metastasis at the time of the initial visit between January 2006 and March 2018 were included in the study. Seventy-four patients were included in this retrospective study. The relationships between variables and prognosis were statistically analysed. Results: The mean patient age was 58.7 years (10–86 years), the mean follow-up period was 75 months (24–173 months). A total of 37 tumours were predominantly located in the anterior compartment of the thigh, 17 in the medial compartment, and 20 in the posterior compartment. Multivariate analysis of the patient clinical data demonstrated that seromas developed more often in the medial compartment tumours and postoperative complications excluding seroma occurred more frequently in patients with two or more muscles resected or stage III tumours. A low Musculoskeletal Tumor Society score was associated with a long operative time (more than 120 min), anterior compartment tumours, and more than two muscle resections. In addition, soft tissue sarcomas in the medial compartment and stage III sarcomas were associated with a low 5-year metastasis-free survival. Conclusions: Soft tissue sarcomas in the medial compartment were associated with postoperative seroma and metastasis, whereas sarcomas in the anterior compartment correlated with low postoperative function. Surgeons should be aware of compartment-specific clinical outcomes in patients with soft tissue sarcomas of the thigh.[Table: see text]

Therapeutic effects and clinical outcomes of immune checkpoint inhibitors on bone metastases in lung cancer

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Background: In recent years, advanced lung cancer patients who received immune checkpoint inhibitors (ICIs) reportedly had a more prolonged overall survival (OS) than those treated with conventional anticancer drugs. However, the therapeutic effect of ICIs on bone metastases remains unclear. The purpose of this study was to investigate the therapeutic effects of ICIs on advanced lung cancer with bone metastasis. Methods: This retrospective study included 58 lung cancer patients (42 men and 16 women; mean age, 66.2±7.8 years) who had been diagnosed with bone metastasis before the initiation of ICI treatment between 2016 and 2019, and the mean follow-up period was 23.2 months. The clinical data such as content of chemotherapy including the bone-modifying agent (BMA), skeletal-related events (SREs), and immune-related adverse events (irAEs) were investigated. The therapeutic effects of ICIs on the primary lung lesions and bone metastases were evaluated by the response evaluation criteria in solid tumors 1.1 (RECIST 1.1) and MD Anderson criteria, respectively. To assess the influence of ICI treatment on prognosis, OS from the diagnosis of bone metastases was compared to the prognostic prediction of Katagiri's score. Results: The most used ICI was pembrolizumab in 27 cases (46.6%). BMA was used in 38 cases (65.6%), and denosumab was used in 31 cases (81.6%). SREs and irAEs were observed in three cases (5.2%) and 13 cases (22.4%), respectively. In the primary lung lesions, the response rate (RR) and disease control rate (DCR) of ICIs were 14.3% and 38.1%, respectively, including one case in CR and 5 cases in PR. In the bone metastatic lesions, the RR and DCR were 38.6% and 75.0%, respectively, including 3 cases in CR and 14 cases in PR. In 17 cases that ICIs responded to bone metastases, nine cases were treated with pembrolizumab (52.9%), and all cases whose evaluations were CR had been treated with concomitant therapy of pembrolizumab and denosumab. The median survival time was 28.1 months and the 2-year OS rate was 51.7%. The 6-, 12-, and 24-month OS rates in this study were more favorable than the prognostic prediction of the Katagiri's score. Conclusions: ICI treatment showed favorable responses to bone metastases in NSCLC and better prognoses than conventional predictive prognosis. Particularly, pembrolizumab may be the most effective, and the therapeutic effect was enhanced by the concomitant use of denosumab.[Table: see text]

Dedifferentiated chondrosarcoma of the middle finger arising from a solitary enchondroma: A case report

BACKGROUND

Dedifferentiated chondrosarcoma (DDCS) accounts for 10% of all chondrosarcomas and has the poorest outcome, with a 5-year survival rate of 7%-25%. DDCS commonly occurs in the femur and pelvis, whereas DDCS of the finger is extremely rare. Furthermore, the histological findings of preexisting solitary enchondroma samples are important and valuable for diagnosing malignant transformations.

CASE SUMMARY

We report our experience with DDCS in the proximal phalanx of the left middle finger of an 87-year-old woman. She had undergone surgery for enchondroma, with curettage and artificial bone grafting, 11 years ago, in the same location. Several years after the primary surgery, the left middle finger gradually started to enlarge, and the growth speed increased in the past year. Plain radiographs showed an expansive osteolytic lesion with calcifications and residual grafting material. Owing to the suspicion of malignancy, we performed ray amputation. Histological findings revealed an abrupt transition between the low-grade chondrosarcoma and dedifferentiated sarcoma components. The dedifferentiated components showed the features of a high-grade undifferentiated pleomorphic sarcoma. The patient was diagnosed with DDCS arising from a preexisting enchondroma. She had no local recurrence or distant metastasis and died of pneumonia 6 years and 10 months after the second surgery.

CONCLUSION

The histological findings of a precursor lesion showed a typical enchondroma, suggesting that DDCS can arise from enchondroma.

The Therapeutic Effect and Clinical Outcome of Immune Checkpoint Inhibitors on Bone Metastasis in Advanced Non-Small-Cell Lung Cancer

Introduction

In advanced non-small-cell lung cancer (NSCLC), immune checkpoint inhibitors (ICIs) have been reported a better treatment outcome on primary lesions, however, the therapeutic effect on bone metastases has not been clarified. This study investigates the therapeutic effect of ICIs on bone metastases in advanced NSCLC.

Methods

The data of patients with advanced NSCLC, treated with ICIs from 2016 to 2019 at our hospital, were analyzed. The therapeutic effects of ICIs on primary lung and metastatic bone lesions, concomitant use of bone modifying agents (BMA), treatment outcomes, and frequency of immune-related adverse events (irAEs) and skeletal-related events (SREs) were investigated.

Results

A total of 29 patients were included (19 men and 10 women; mean age, 64.2 years). Among the ICIs, pembrolizumab was the most used (55.2%), and concomitant use of BMA was prevalent in 21 patients (zoledronic acid=1, denosumab=20). The therapeutic effect was partial response (PR) in 10.3% (n=3) on primary lung lesions by RECIST 1.1, complete response (CR) in 6.9% (n=2) and PR in 17.2% (n=5) on bone metastatic lesions by MDA criteria. ICIs suppressed the progression of bone metastasis in 21 cases (72.4%). All patients in CR and PR were treated with pembrolizumab and denosumab. SREs and irAEs were developed in 3.4% (n=1) and 20.7% (n=6), respectively. The median survival time after treatment with ICIs was 11.0 months. Concomitant therapy with ICIs and denosumab significantly prolonged the overall survival compared to ICI-only therapy (16.0 months vs. 2.5 months, p<0.01).

Conclusions

This study showed that treatment with ICIs may successfully suppress the progression of bone metastasis in advanced NSCLC. Pembrolizumab with denosumab had the highest therapeutic effect on both primary lung lesions and bone metastases. Systemic treatment with this combination and conservative treatment of bone metastasis could be one of the options in the treatment of advanced NSCLC.

Clinical characteristics of patients with undergoing unplanned excisions of malignant soft tissue tumors

INTRODUCTION

Malignant soft tissue tumors are rare tumors representing <1% of all malignancies. As these tumors are rare, it is not uncommon that malignant soft tissue tumor excision is performed without the required preoperative imaging, staging, or wide resection margins for sarcomas. The purpose of this study was to investigate the characteristics of patients with undergoing unplanned excisions. Risk factors for tumor recurrence and mortality in patients treated with unplanned excisions were also analyzed.

METHODS

Forty-nine patients who underwent unplanned excision at other hospitals and additional wide excision at our hospital between January 2002 and December 2018 were identified. Among them, 42 patients with follow-up for more than 1 year were included in this retrospective study. The relationships between sex, age, tumor depth, histological grade, location, size, surgical margin at additional wide excision, residual tumor, reconstruction, kind of hospital where the primary excision was done (sarcoma vs non-sarcoma center), preoperative examination, chemotherapy, radiation therapy, and oncological outcomes were statistically analyzed.

RESULTS

Mean patient age was 57.3 years (15-85 years) and the mean observation period was 72.5 months (14-181 months). This analysis showed 53.8% tumors that underwent unplanned excisions were small (<5 cm) and 70.7% tumors were superficial. Multivariate analysis revealed that a positive margin during additional wide excision was significantly associated with a lower 5-year LRFS (p < 0.01).

CONCLUSION

Most of the tumors underwent unplanned excisions were small (<5 cm) and superficial. Surgeons should be aware that a positive margin during additional wide excision is an independent risk factor for local recurrence.

Primary total knee arthroplasty assisted by computed tomography-free navigation for secondary knee osteoarthritis following massive calcium phosphate cement packing for distal femoral giant-cell bone tumor treatment: a case report

BACKGROUND

Giant cell tumor of bone (GCTB) is an intermediate tumor commonly arising from the epiphysis of the distal femur and proximal tibia. Standard GCTB treatment is joint-preserving surgery performed using thorough curettage and the filling of the cavity with allo-, auto-, polymethyl methacrylate (PMMA), or synthetic bone graft. Calcium phosphate cement (CPC) is an artificial bone substitute, which has the benefit of being able to adjust defects, consequently inducing immediate mechanical strength, and promoting biological healing. Secondary osteoarthritis may occur following GCTB treatment and may need additional surgery if severe. However, details regarding surgery for secondary osteoarthritis have not been fully elucidated. There are no reports on the use of total knee arthroplasty (TKA) for the treatment of secondary osteoarthritis following CPC packing. The insertion of an alignment rod is a standard procedure in TKA; however, it was difficult to perform in this case due to CPC. Therefore, we used a computed tomography (CT)-free navigation system to assist the distal femur cut. This study presents a knee joint secondary osteoarthritis case following CPC packing for GCTB curettage that was treated with standard TKA.

CASE PRESENTATION

A 67-year-old Japanese woman, who was previously diagnosed with left distal femur GCTB and was treated by curettage and CPC packing 7 years ago, complained of severe knee pain. Left knee joint plain radiography revealed Kellgren and Lawrence (K-L) grade 4 osteoarthritis without evidence of tumor recurrence. Therefore, she was scheduled for TKA. There are no reports on the cutting of a femoral condyle surface with massive CPC with accurate alignment. Because it is difficult to insert the alignment rod intramedullary and cut the femoral condyle with CPC, we planned CT-free navigation-guided surgery for accurate bone cutting using an oscillating tip saw system to prevent CPC cracks. We performed standard TKA without complications, as planned. Postoperative X-ray showed normal alignment. Knee Society Knee Score (KSKS) and Knee Society Function Score (KSFS) ameliorated from 27 and 29 to 64 and 68, respectively The patient can walk without a cane postoperatively.

CONCLUSION

There was no report about the surface TKA guided by CT-free navigation after primary GCT surgery with CPC. We believe that this case report will help in planning salvage surgery for secondary osteoarthritis after CPC packing.

Pretreatment Neutrophil Count and Platelet-lymphocyte Ratio as Predictors of Metastasis in Patients With Osteosarcoma

BACKGROUND/AIM

Systemic inflammation responses have been associated with cancer development, progression and metastasis. Little is known about the risk of metastasis based on inflammatory-based scores in patients with osteosarcoma.

PATIENTS AND METHODS

A total of 65 osteosarcoma patients without metastasis at presentation were enrolled in this retrospective study. All had been diagnosed histologically, and their laboratory data at the first visit were collected from medical records. The inflammation-based scores, tumor size, location, staging, pathological fracture, treatment methods, follow-up periods, and metastasis-free duration were evaluated.

RESULTS

A multivariate Cox regression analysis revealed that a high platelet-lymphocyte ratio (PLR) >116 [hazard ratio (HR)=3.8, 95% confidence interval =1.5-9.3; p<0.01], and neutrophil count (NC) ≤4,030/μl (HR=4.5, 95%CI=1.7-12.3; p<0.01), were independent risk factors significantly associated with metastasis of osteosarcoma patients.

CONCLUSION

The combination of a high PLR >116 and NC ≤4,030/μl before treatment was a useful inflammatory-based prognostic indicator for metastasis in patients with osteosarcoma.

Therapeutic Targets and Emerging Treatments in Advanced Chondrosarcoma

Due to resistance to standard anticancer agents, it is difficult to control the disease progression in patients with metastatic or unresectable chondrosarcoma. Novel therapeutic approaches, such as molecule-targeting drugs and immunotherapy, are required to improve clinical outcomes in patients with advanced chondrosarcoma. Recent studies have suggested several promising biomarkers and therapeutic targets for chondrosarcoma, including IDH1/2 and COL2A1. Several molecule-targeting agents and immunotherapies have shown favorable antitumor activity in clinical studies in patients with advanced chondrosarcomas. This review summarizes recent basic studies on biomarkers and molecular targets and recent clinical studies on the treatment of chondrosarcomas.

A scoring system combining clinical, radiological, and histopathological examinations for differential diagnosis between lipoma and atypical lipomatous tumor/well-differentiated liposarcoma

This study evaluated the diagnostic accuracy of clinical, radiological, and histopathological examinations for differential diagnosis between atypical lipomatous tumor (ALT)/well-differentiated liposarcoma (WDLS) and lipoma, and aimed to develop a new combined scoring system for the preoperative diagnosis of ALT/WDLS. Eighty-nine lipomas and 56 ALT/WDLS were included and their clinical characteristics, magnetic resonance imaging (MRI) findings, histological findings by hematoxylin and eosin (HE) staining were investigated. Then, univariate and multivariate logistic regression analyses were performed for the findings, and a combined scoring system consisted of predictive factors of ALT/WDLS was developed. The univariate and multivariate logistic regression analyses revealed that tumor location (lower extremity), deep site, size (> 11 cm), thick septa (> 2 mm), enhancement of septa or nodular lesions, and lipoblasts were significantly different for the diagnosis of ALT/WDLS. We developed a combined scoring system based on the six predictive factors (total 0-16 points, the cutoff was 9 points). The area under the curve was 0.945, and sensitivity was 87.6% and specificity was 91.1% by the receiver operating characteristics curve. This combined scoring system does not require special equipment and reagents such as fluorescence in situ hybridization (FISH), and anyone can use it easily in many medical institutions with high diagnostic accuracy.

Monostotic Fibrous Dysplasia in the Femur Strongly Expressing RANKL With Concomitant Osteoporotic Vertebral Compression Fracture: A Case Report

BACKGROUND/AIM

This study aimed to present a rare case of fibrous dysplasia (FD) in a healthy young adult man with a concomitant osteoporotic vertebral compression fracture. FD is a benign lesion of the bone characterized by replacement of the medullary component with fibro-osseous tissue that contains abnormally arranged trabeculae of immature woven bone. Recently it has been reported that several bone tumors including FD express the receptor activator of nuclear factor-kappa B (RANK) and its ligand (RANKL). Therefore, we hypothesized that FD contributed to osteoporosis, linked by the RANK-RANKL pathway of osteoclastogenesis.

CASE REPORT

We report the case of a healthy man with monostotic femoral fibrous dysplasia (FD) with concomitant 7 ^th thoracic vertebra compression fracture due to osteoporosis [young adult mean (YAM) was 79% in bone mineral density (BMD)]. After curettage of the FD, artificial bone grafting in the cavity, and administration of alendronate sodium, BMD improved considerably within 9 months. FD is a benign bone condition in which abnormal fibrous tissue replaces normal bone. The axis of the receptor activator of nuclear factor-kappa B (RANK) and its ligand (RANKL) has been implicated in osteoporosis pathogenesis. RANKL immunohistochemical staining was performed, and strong staining of stromal cells was observed compared to other FD cases that showed weak to moderate staining.

CONCLUSION

The presence of FD might have contributed to the low BMD due to the RANK-RANKL axis acting as osteoclastogenesis stimulator.

Impact of Tumor Growth Speed of Primary Lesions on the Clinical Outcomes of Appendicular Skeletal Metastases

BACKGROUND/AIM

This study aimed to investigate the clinical influence of the growth speed of primary lesions on appendicular skeletal metastases to provide an optimal treatment strategy for the metastases.

PATIENTS AND METHODS

Fifty-seven patients who underwent surgery for appendicular skeletal metastases between 2008 and 2020 were included. According to the growth speed of primary lesions, the patients were divided into the S group (slow-to-moderate, n=34) and the R group (rapid, n=23), and the outcomes were investigated.

RESULTS

The period from diagnosis of skeletal metastases to pathological fracture (PF) was shorter in the R group than in the S group (p=0.24). The overall survival of the S group was significantly better than that of the R group (p=0.02).

CONCLUSION

The appendicular skeletal metastases of the primary tumor with rapid growth speed have a high risk of PFs developed early from the diagnosis of skeletal metastases, and the prognosis may be poor.

Osteosarcoma Patient-derived Orthotopic Xenograft (PDOX) Models Used to Identify Novel and Effective Therapeutics: A Review

BACKGROUND/AIM

Recurrent osteosarcoma is recalcitrant with poor response rates to first-line chemotherapy due to heterogeneity and metastatic potential. This disease requires novel drug discovery and precision treatment.

MATERIALS AND METHODS

The osteosarcoma patient-derived orthotopic xenograft (PDOX) mouse model mimics the clinical disease and has identified effective clinically-approved drugs and experimental agents, especially drug combinations, that hold much clinical promise.

RESULTS

Effective treatment for drug-resistant osteosarcoma includes regorafenib, as monotherapy, and temozolomide-irinotecan, trabectedin-irinotecan, sorafenib-everolimus, sorafenib-palbociclib, and olaratumab-doxorubicin-cisplatinum, as combinations.

CONCLUSION

The PDOX model can be used to improve the outcome of osteosarcoma patients, including individualized, precision therapy.

Effectiveness of silicone-based resilient denture liners on the patient-reported chewing ability: A randomized controlled trial

PURPOSE

This randomized controlled trial (RCT) aimed to elucidate the effectiveness of silicone-based resilient denture liners on perceived chewing ability.

METHODS

The RCT included completely edentulous patients on both the maxilla and mandible, who were willing to fabricate a new set of complete dentures. A random permuted block method (block size: 4) was used to assign groups to receive maxilla conventional complete denture and mandibular with either a conventional complete denture (CD) or complete demure relined with silicone-based resilient denture liner (RD). The patient-reported chewing ability of six foods, soybean curd, fish sausage, soybean sprout, cubic rice cracker, hard rice cracker, and dry squid, on a 100-mm visual analog scale was measured and reported at the final adjustment and three months after the final adjustment. Mann-Whitney U test was used to analyze the differences between the CD and RD (p < 0.05).

RESULTS

Edentulous patients wearing mandibular complete denture with RD had a higher patient-reported chewing ability than those wearing a CD, but the fish sausage did not in the RD three months after the final adjustment. It also took three months for the patient-reported masticatory ability to improve for cubic rice crackers, hard rice crackers, and dry squid and to show a difference between the RD and CD groups.

CONCLUSION

Although limited to some food types, mandibular complete dentures relined with silicone-based liners improved patient-reported chewing ability.

Multikinase-Inhibitor Screening in Drug-resistant Osteosarcoma Patient-derived Orthotopic Xenograft Mouse Models Identifies the Clinical Potential of Regorafenib

BACKGROUND/AIM

Osteosarcoma is a recalcitrant heterogenous malignancy. The aim of the present study was to compare a series of multikinase inhibitors (MKIs) for efficacy on two drug-resistant osteosarcoma patient-derived orthotopic xenograft (PDOX) models in order to identify a clinical candidate.

MATERIALS AND METHODS

The two osteosarcoma PDOX models were tested for response to the following MKIs: pazopanib, sunitinib, sorafenib, crizotinib, and regorafenib, in comparison to first-line treatment with cisplatinum and an untreated control.

RESULTS

Regorafenib led to regression of osteosarcoma in both PDOXs. Total necrosis was observed pathologically in the regorafenib-treated tumors. Sorafenib arrested growth, without inducing regression, in one osteosarcoma model but not the other, and the other MKIs only slowed tumor growth.

CONCLUSION

The present study demonstrated that regorafenib is much more effective than the other MKIs tested and has clinical potential against recalcitrant osteosarcoma.

Clinical outcomes of frozen autograft reconstruction for the treatment of primary bone sarcoma in adolescents and young adults

Age affects the clinical outcomes of cancer treatment, including those for bone sarcoma. Successful reconstruction using frozen autograft after excision of bone sarcoma has been reported; however, little is known about the clinical outcomes of frozen autograft reconstruction according to age. The purpose was to evaluate the clinical outcomes of the frozen autograft reconstruction focusing on skeletally mature adolescents and young adults (AYAs) that was 15 to 39 years of age. A total of 37 AYA patients with primary bone sarcoma on the appendicular skeleton were enrolled in this study. The mean follow-up period was 89 months. The graft survival (GS), overall survival (OS), recurrence-free survival (RFS), complications and the function were retrospectively evaluated using medical records. The 10-year GS, OS, and RFS rates were 76%, 84%, and 79%, respectively. Bone union was achieved with a rate of 94% within 1 year after surgery, and nonunion (n = 1) and fracture (n = 2) were infrequently observed. Graft removal was performed in 7 cases, and the most common reason for the removal was infection (n = 5). The Musculoskeletal Tumor Society score was excellent in 23 cases of the available 29 cases. Frozen autograft reconstruction for AYAs showed excellent clinical outcomes, although the long-term follow-up is required.

Evaluation of locomotive syndrome in patients receiving surgical treatment for degenerative musculoskeletal diseases: A multicentre prospective study using the new criteria

OBJECTIVES

This study aimed to evaluate the condition of patients with locomotive syndrome (LS) and their improvement after undergoing surgery for degenerative musculoskeletal diseases using the new criteria, including stage 3.

METHODS

In total, 435 patients aged ≥40 years (167 middle-aged and 268 older) were divided into four groups based on the disease location: the lumbar (n = 118), hip (n = 191), knee (n = 80), and foot and ankle (n = 46) groups. Patients were evaluated by pre- and 1 year postoperative LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale.

RESULTS

The pre- and postoperative prevalence of LS stage 3 were 78% and 29%, respectively. The postoperative LS stage improved in 62% of patients (77% and 53% in the middle-aged and older groups, respectively). Overall, the knee group showed the worst results, and the foot and ankle groups showed the best pre- and postoperative results. The pre- and postoperative prevalence of LS stage 3 according to the 25-Question Geriatric Locomotive Function Scale were comparable to those based on the total assessment.

CONCLUSIONS

The new LS stage criteria are appropriate, and the 25-Question Geriatric Locomotive Function Scale is a good option for evaluating patients requiring surgery.

A Radiological Scoring System for Differentiation between Enchondroma and Chondrosarcoma

Simple Summary

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. Methods: To evaluate the diagnostic usefulness of radiological findings for differentiation between enchondromas and chondrosarcomas, correlations between various radiological findings and final diagnoses were investigated. Based on the correlations, a scoring system combining these findings was developed. Results: In a cohort of 81 patients, periosteal reaction on X-ray, endosteal scalloping and cortical defect on CT, extraskeletal mass, multilobular lesion, abnormal signal in adjacent tissue on MRI, and increased uptake in bone scan and thallium scan was significantly correlated with final diagnoses. Based on the correlations, a radiological scoring system combining radiological findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and chondrosarcomas were 88%, 89%, and 88%, respectively. Conclusion: Comprehensive assessment combining radiological findings is recommended to differentiate between enchondromas and ACTs/chondrosarcomas.

Abstract

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. Methods: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. Results: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). Conclusion: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas.

Delayed Initiation of Treatment Is Associated With Metastasis of Malignant Bone Tumor

BACKGROUND/AIM

The delayed initiation of treatment is not associated with good clinical outcomes in patients with malignancies. However, few previous studies have examined prognostic factors, including the delayed initiation of treatment, in malignant bone tumors.

PATIENTS AND METHODS

One hundred and one patients with malignant bone tumors were enrolled. Univariate and multivariate analyses were performed to identify factors predicting metastasis, including factors that delay the initiation of treatment.

RESULTS

The multivariate analysis revealed that high-grade bone malignancy (p<0.01), a >30-day delay in referral to a specialized hospital by a general practitioner (p=0.03), and large tumor size (>77 mm) (p=0.04), were independently associated with metastasis of malignant bone tumors.

CONCLUSION

When general practitioners notice a patient with a >77 mm bone tumor, early referral to a specialized hospital within one month might be essential for preventing metastasis.

Significant Improvement After Surgery for a Symptomatic Osteoblastoma in a Patient with Camurati-Engelmann Disease: Case Report and Literature Review

Camurati-Engelmann disease (CED) is a rare, progressive diaphyseal dysplasia characterized as diaphyseal hyperostosis and sclerosis of the long bones. Corticosteroids, bisphosphonates, and losartan have been reported to be effective systemic medications used to reduce CED symptoms. There are no reports of osteoblastoma in patients with CED, and osteoblastoma in the distal radius is rare. We present a patient diagnosed with CED, based on radiological and histological examinations, at 11 years old. At 22 years old, she experienced severe pain in her right forearm and was treated with bisphosphonate, losartan, and prednisolone; however, the pain continued. An expansive and sclerotic lesion at the distal radius was observed on radiography. A follow-up plain radiograph indicated that the lesion was growing. Fluorodeoxyglucose positron emission tomography revealed solitary, intense radiotracer uptake, and a biopsy and surgical resection were performed due to suspected malignancy. Pathologic analysis showed anastomosing bony trabeculae rimmed by osteoblasts observed in a loose fibrovascular stroma. The lesion was diagnosed as an osteoblastoma. Following bone excision and artificial bone grafting, the patient's severe pain almost completely disappeared. At final follow-up, no evidence of osteoblastoma recurrence was noted. To our knowledge, this is the first case report of osteoblastoma arising in a patient with CED. Bone excision and artificial bone grafting may be a treatment option for local symptomatic osteoblastoma in patients with CED.

[The oral function of community-dwelling older adults complaining of an oral function deterioration: An examination using the oral function-related items of the Questionnaire for Latter-stage Elderly People]

AIM

The oral function-related items of the newly developed "Questionnaire for Latter-stage Elderly People" are based on two items of the Kihon checklist assessing the masticatory and swallowing functions. In this study, we estimated the questionnaire's application rate and investigated the oral function of the respondents.

METHODS

Included were 699 older adults (274 men/425 women, average age, 73.4±6.6 years old). Those who responded positively to the related items were considered to have decreased swallowing and masticatory functions. The specific oral function was assessed based on the number of present and functional teeth; oral hygiene; oral moisture; occlusal force; oral diadochokinesis /pa/, /ta/, /ka/; tongue pressure; mixing ability; shearing ability; and Eating Assessment Tool (EAT)-10 (reference, score ≥3).

RESULTS

The rates of decreased masticatory and swallowing functions were 21.5% and 26.6%, respectively, while 7.4% of participants had both. Those with a decreased masticatory function showed fewer present teeth; a lower occlusal force, oral diadochokinesis /pa/, mixing ability, shearing ability, and higher EAT-10 scores.Those with a decreased swallowing function only had higher EAT-10 scores. In the early- and latter-stage elderly, the decreased masticatory function rates were 15.6% and 29.4%, respectively, the decreased swallowing function rates were 27.8% and 25.0%, respectively, and the rates of both decreased masticatory and swallowing functions were 6.0% and 9.5%, respectively.

CONCLUSION

The older adults who responded positively to the related questionnaire items, especially for items related to masticatory function, had a decreased oral function in multiple respects. The items related to the oral function in the Questionnaire for Latter-stage Elderly People are considered useful for identifying older adults with a decreased oral function.

Osteosarcoma-Derived Small Extracellular Vesicles Enhance Tumor Metastasis and Suppress Osteoclastogenesis by miR-146a-5p

Osteosarcoma is the most frequent type of primary bone tumor in children and adolescents, thus care for patients with malignant osteosarcoma is strongly required. The roles of small extracellular vesicles (SEVs) in enhancing metastases have been demonstrated in multiple tumors, but they are still poorly understood in osteosarcoma. Hence, this study investigated the effects of SEVs on progression and the tumor microenvironment in mice and patients. In an orthotopic implantation study, we found that osteosarcoma-derived SEVs had the potential to enhance metastases and angiogenesis. In addition, osteosarcoma-derived SEVs decreased the number of mature osteoclasts in vivo. In vitro osteoclastogenesis studies revealed that the inhibition of osteoclast maturation by osteosarcoma-derived SEVs was mediated by suppressing the NF-κB signal pathway. MicroRNA analysis of SEVs from different malignant human osteosarcomas revealed that miR-146a-5p was involved in the inhibition of osteoclastogenesis. In osteosarcoma patients, lower numbers of osteoclasts in biopsy specimens at the first visits were correlated with higher malignancy. These findings indicated that osteosarcoma-derived SEVs enhance distant metastasis of osteosarcomas by inhibiting osteoclast maturation, which may be a useful prognostic marker. This diagnostic method may enable to predict malignancy at early stage, and help to provide optimal care to patients with risk of high malignancy.

Complete Response of Bone Metastasis in Non-small Cell Lung Cancer With Pembrolizumab: Two Case Reports

AIM

To report two cases in which treatment with pembrolizumab for advanced non-small cell lung cancer (NSCLC) with bone metastasis of the long bone of the lower extremity in a state of impending fracture significantly ameliorated both lung tumor and bone metastasis.

CASE REPORT

Case 1 was a 74-year-old woman diagnosed with metastasis of NSCLC in the left tibia and case 2 was a 71-year-old man diagnosed with metastasis of NSCLC in the right femur; their bone metastases were in a state of impending fracture. Disease in both cases was already in stage IVB and they received systemic therapy using pembrolizumab, whilst the bone metastases were treated conservatively. After 3 months, both patients showed a complete response with remarkable osteosclerotic changes in bone metastases and the size of lung tumors was reduced.

CONCLUSION

These results might imply a novel strategy for systemic treatment with pembrolizumab is required, even in case of impending fracture in advanced NSCLC.

Effectiveness of silicone-based resilient denture liners on masticatory function: A randomised controlled trial

OBJECTIVES

This randomised controlled trial aimed to compare the masticatory function between the silicone-based resilient denture liner and conventional denture among edentulous patients.

METHODS

The trial included edentulous patients who were willing to have a new set of complete dentures. Participants were randomly assigned to receive mandibular complete dentures with either a 1) conventional denture base (CD group) or (2) silicone-based resilient denture liner (RD group). Masticatory performance (evaluated with gummy jelly) and the maximum occlusal force were measured at baseline, on final adjustment, and at 3 months after the final adjustment. The outcomes were analyzed using two-way mixed analysis of variance and a paired t-test. The statistical significance was set at p < 0.05.

RESULTS

The masticatory performance was lower in the RD group than in the CD group; it increased significantly over time in the CD group, but not in the RD group. The maximum occlusal force in the RD group was significantly higher than that in the CD group; it increased significantly over time in the RD group, but not in the CD group.

CONCLUSIONS

Silicone-based RD liners applied to mandibular complete dentures are effective in improving the maximum occlusal force but not the masticatory performance, as measured with gummy jelly.

CLINICAL SIGNIFICANCE

Prior evidence has suggested that mandibular complete dentures with resilient denture liners improve masticatory function. However, the results of this study indicate that difficulties may remain with the mastication of foods with a certain texture (e.g., gummy jelly).