Bone Metastases.

ABSTRACT: Bone metastases occur frequently in common malignancies such as breast and prostate cancer. They are responsible for considerable morbidity and skeletal-related events. Fortunately, there are now several systemic, focal, and targeted therapies that can improve quality and length of life, including radionuclide therapies. It is therefore important that bone metastases can be detected as early as possible and that treatment can be accurately and sensitively monitored. Several bone-specific and tumor-specific single-photon emission computed tomography and positron emission tomography molecular imaging agents are available, for detection and monitoring response to systemic therapeutics, as well as theranostic agents to confirm target expression and predict response to radionuclide therapies.

[Management of bone metastasis in non-small cell lung cancer]. / Prise en charge des métastases osseuses du cancer pulmonaire non à petites cellules.

Lung cancer is notoriously known for its predisposition to metastasize to the bones. Diagnostic tools, including positron emission tomography coupled with computed tomography, offer increased sensitivity in detecting bone infiltration. Management strategies encompass a multidisciplinary approach, including pharmacological pain management, anti-resorptive therapy, radiotherapy, interventional techniques, and surgery. This article provides an in-depth analysis of the incidence and distribution of bone metastases, skeletal-related events (SRE), diagnostic imaging techniques, and contemporary therapeutic strategies to prevent SRE. Systemic anticancer therapy and pain management, although crucial for treating BM, are not discussed in this article.

Le cancer du poumon est notoirement connu pour sa prédisposition à métastaser dans les os. Les outils diagnostiques, notamment la tomographie par émission de positrons couplée à la tomodensitométrie, offrent une sensibilité accrue pour détecter l'infiltration osseuse. Les stratégies de prise en charge englobent une approche multidisciplinaire, comprenant le traitement médicamenteux de la douleur, la thérapie antirésorptive, la radiothérapie, les techniques interventionnelles ainsi que la chirurgie. Cet article propose une analyse approfondie de l'incidence et de la distribution des métastases osseuses (MO), des événements liés au squelette (SRE), des techniques d'imagerie diagnostique et des stratégies thérapeutiques contemporaines pour prévenir les SRE. Le traitement systémique anticancéreux et la gestion de la douleur, bien que cruciaux pour traiter les MO, ne sont pas discutés dans cet article.

Cinobufotalin Capsule Combined with Zoledronic Acid in the Treatment of Pain Symptoms and Clinical Efficacy in Prostate Cancer Patients with Bone Metastases: A Retrospective Study.

OBJECTIVE: To retrospectively analyse the effects of cinobufotalin capsule combined with zoledronic acid on pain symptoms and clinical efficacy of prostate cancer patients with bone metastases. METHODS: Patients with prostate cancer with bone metastasis admitted to our hospital from January 2021 to December 2022 were selected as study subjects. They were divided into the control group (treated with zoledronic acid) and the combined group (cinobufotalin capsules were added on the control group basis) according to different recorded treatment methods. The efficacies of the two groups after matching, lumbar L1-4 bone mineral density (BMD), serum calcium, serum phosphorus, visual analogue scale (VAS) score and Karnofsky performance status (KPS) score before and after treatment were compared, and adverse reactions were statistically analysed. RESULTS: A total of 102 patients were included in the study, encompassing 52 patients in the combined group and 50 patients in the control group. After 1:1 preference score matching, 64 patients were included in the two groups. No significant difference in baseline data was found between the two groups (p > 0.05). The total effective rate of the combination group was higher than that of the control group (p < 0.05). No significant differences in L1-4 bone mineral density, serum calcium and phosphorus, VAS score and KPS score were observed between the two groups prior to treatment (p > 0.05). After treatment, the L1-4 bone mineral density (BMD) and KPS score of the combined group decreased to less than those of the control group, the VAS score was lower than that of the control group, and the serum calcium and phosphorus level increased but less than that of the control group (p < 0.05). No significant difference in adverse reactions was found between the two groups (p > 0.05). CONCLUSIONS: Cinobufotalin capsule combined with zoledronic acid had ideal efficacy in the treatment of prostate cancer in patients with bone metastasis. This approach could improve their bone density and quality of life, improve their calcium and phosphorus metabolism, reduce their pain symptoms and provide increased safety. It may have an important guiding role in formulating future clinical treatment plans for patients with prostate cancer and bone metastasis.

Extraneural metastatic ependymoma: distant metastasis to the pleura, lungs, lymph nodes and bone.

Ependymomas are neuroepithelial tumours arising from ependymal cells surrounding the cerebral ventricles that rarely metastasise to extraneural structures. This spread has been reported to occur to the lungs, lymph nodes, liver and bone. We describe the case of a patient with recurrent CNS WHO grade 3 ependymoma with extraneural metastatic disease. He was treated with multiple surgical resections, radiation therapy and salvage chemotherapy for his extraneural metastasis to the lungs, bone, pleural space and lymph nodes.

ZEB1-AS1 mediates bone metastasis through targeting miR-320b/BMPR1A axis in lung cancer.

OBJECTIVE: This study aimed to explore the role and regulatory mechanism of lncRNA ZEB1-AS1 in lung cancer. METHODS: The expression of ZEB1-AS1 and miR-320b was determined by qRT-PCR. Cell viability, proliferation migration, and invasion were assessed using the CCK-8, colony-forming, and Transwell assay. EMT markers were quantified using western blot. The growth of subcutaneous tumor growth and metastatic bone tumors was evaluated in mouse model of lung cancer. Additionally, metastatic bone tumors were examined using H&E staining. RESULTS: ZEB1-AS1 expression was upregulated, while miR-320b levels were downregulated in lung cancer. Knockdown of ZEB1-AS1 resulted in a significant suppression of cell viability, proliferation, migration, invasion, and EMT in A549 cells. Furthermore, we confirmed the targeting relationship between ZEB1-AS1 and miR-320b, as well as between miR-320b and BMPR1A. Our findings suggested that ZEB1-AS1 regulated cell viability, proliferation, migration, and invasion, as well as EMT, in lung cancer cells by targeting the miR-320b/BMPR1A axis. Moreover, our in vivo experiments confirmed that ZEB1-AS1 mediated bone metastasis through targeting miR-320b/BMPR1A axis in mice with lung cancer. CONCLUSION: ZEB1-AS1 mediated bone metastasis through targeting miR-320b/BMPR1A axis in lung cancer.

Pain response in single-fraction 8-Gy radiotherapy for painful non-bone-metastasis tumors: a single-center retrospective study.

The effectiveness of single-fraction 8-Gy radiotherapy for painful bone metastases has been verified in numerous randomized controlled trials. However, few reports have described the effectiveness of single-fraction 8-Gy radiotherapy in painful tumors other than bone metastases. We conducted a retrospective analysis to evaluate the pain response to single-fraction 8-Gy radiotherapy in painful non-bone-metastasis tumors. We included patients who had received single-fraction 8-Gy radiotherapy for such tumors between January 2017 and December 2022, excluding those with brain metastases, hematological tumors and those who received re-irradiation. Pain response assessment was based on the best responses documented in the medical records and conducted by two radiation oncologists. A total of 36 eligible patients were included in this study. The irradiation sites included primary lesions in eight patients, lymph node metastases in eight, muscle metastases in seven, pleural dissemination in four, skin/subcutaneous metastases in four and other sites in five. Pain response was assessed in 24 patients after radiotherapy. Pain response rate was 88% in evaluable patients; 21 of the 24 patients experienced response. The median assessment date for pain response was 37 days (range: 8-156 days) after radiotherapy. Re-irradiation was performed in four patients (11%). Single-fraction 8-Gy radiotherapy seemed to be a promising treatment option for painful non-bone-metastasis tumors and warrants further investigation.

[Establishment of Dual Fluorescent Labeled Human High Bone Metastasis 
Lung Adenocarcinoma Cell Line and Transcriptomic Characterization Analysis].

BACKGROUND: Bone is a common site for metastasis in lung adenocarcinoma, but the mechanism behind lung adenocarcinoma bone metastasis is still unclear. And currently, there is a lack of easily traceable and stable lung adenocarcinoma bone metastasis cell models, which limits the research on the mechanism of lung adenocarcinoma bone metastasis. The establishment of human lung adenocarcinoma cell line that are highly metastatic to bone, labeled with green fluorescent proteins (GFP) and fireflies luciferase (LUC), along with transcriptomic characterization, would be beneficial for research on lung adenocarcinoma bone metastasis and provide new experimental methods. METHODS: The human lung adenocarcinoma cell line A549-GFP-LUC was injected into nude mice via the left ventricle to construct a bone metastasis model, and was domesticated in vivo for three consecutive times to obtain the human high bone metastasis lung adenocarcinoma cell line A549-GFP-LUC-BM3; cell counting kit-8 (CCK-8), colony formation assay, scratch wound assays, Transwell assay and Western blot were used to compare the proliferation and invasion abilities of A549-GFP-LUC-BM3 with the parental cells. A549-GFP-LUC-BM3 cells and parental cells were further analyzed by transcriptomic sequencing. RESULTS: Human high-bone metastatic lung adenocarcinoma cells A549-GFP-LUC-BM3 was successfully established. Compared to parental cells, this cells exhibited a significantly higher incidence of bone metastasis and enhanced in vitro proliferation, migration, and invasion abilities. Transcriptomic sequencing results revealed that the A549-GFP-LUC-BM3 cell line had 2954 differentially expressed genes compared to the parental cells, with 1021 genes up-regulated and 1933 genes down-regulated. Gene Ontology (GO) functional enrichment analysis indicated that the differentially expressed genes were primarily localized in cellular components such as the cell periphery. The molecular functions identified as significantly enriched included signaling receptor activity, calcium ion binding, and extracellular matrix structural constituent. Additionally, the biological processes found to be enriched were cell adhesion and biological adhesion. The enrichment analysis conducted using the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the differentially expressed genes were primarily involved in the metabolism of xenobiotics by cytochrome P450, retinol metabolism, drug metabolism-cytochrome P450, cell adhesion molecules, steroid hormone biosynthesis, and the nuclear factor kappa B (NF-κB) signaling pathway. CONCLUSIONS: The highly bone-metastatic human lung adenocarcinoma cell line with GFP and luciferase double labeling was successfully established. The biological behavior and transcriptome sequencing of the cell line suggest that it has a high bone-metastatic potential.

Promoter hypermethylation as a novel regulator of ANO1 expression and function in prostate cancer bone metastasis.

Despite growing evidence implicating the calcium-activated chloride channel anoctamin1 (ANO1) in cancer metastasis, its direct impact on the metastatic potential of prostate cancer and the possible significance of epigenetic alteration in this process are not fully understood. Here, we show that ANO1 is minimally expressed in LNCap and DU145 prostate cancer cell lines with low metastatic potential but overexpressed in high metastatic PC3 prostate cancer cell line. The treatment of LNCap and DU145 cells with DNMT inhibitor 5-aza-2'-deoxycytidine (5-Aza-CdR) potentiates ANO1 expression, suggesting that DNA methylation is one of the mechanisms controlling ANO1 expression. Consistent with this notion, hypermethylation was detected at the CpG island of ANO1 promoter region in LNCap and DU145 cells, and 5-Aza-CdR treatment resulted in a drastic demethylation at promoter CpG methylation sites. Upon 5-Aza-CdR treatment, metastatic indexes, such as cell motility, invasion, and metastasis-related gene expression, were significantly altered in LNCap and DU145 cells. These 5-Aza-CdR-induced metastatic hallmarks were, however, almost completely ablated by stable knockdown of ANO1. These in vitro discoveries were further supported by our in vivo observation that ANO1 expression in xenograft mouse models enhances the metastatic dissemination of prostate cancer cells into tibial bone and the development of osteolytic lesions. Collectively, our results help elucidate the critical role of ANO1 expression in prostate cancer bone metastases, which is epigenetically modulated by promoter CpG methylation.

Implementation Strategies to Promote Short-Course Radiation for Bone Metastases.

Importance: For patients with nonspine bone metastases, short-course radiotherapy (RT) can reduce patient burden without sacrificing clinical benefit. However, there is great variation in uptake of short-course RT across practice settings. Objective: To evaluate whether a set of 3 implementation strategies facilitates increased adoption of a consensus recommendation to treat nonspine bone metastases with short-course RT (ie, ≤5 fractions). Design, Setting, and Participants: This prospective, stepped-wedge, cluster randomized quality improvement study was conducted at 3 community-based cancer centers within an existing academic-community partnership. Rollout was initiated in 3-month increments between October 2021 and May 2022. Participants included treating physicians and patients receiving RT for nonspine bone metastases. Data analysis was performed from October 2022 to May 2023. Exposures: Three implementation strategies-(1) dissemination of published consensus guidelines, (2) personalized audit-and-feedback reports, and (3) an email-based electronic consultation platform (eConsult)-were rolled out to physicians. Main Outcomes and Measures: The primary outcome was adherence to the consensus recommendation of short-course RT for nonspine bone metastases. Mixed-effects logistic regression at the bone metastasis level was used to model associations between the exposure of physicians to the set of strategies (preimplementation vs postimplementation) and short-course RT, while accounting for patient and physician characteristics and calendar time, with a random effect for physician. Physician surveys were administered before implementation and after implementation to assess feasibility, acceptability, and appropriateness of each strategy. Results: Forty-five physicians treated 714 patients (median [IQR] age at treatment start, 67 [59-75] years; 343 women [48%]) with 838 unique nonspine bone metastases during the study period. Implementing the set of strategies was not associated with use of short-course RT (odds ratio, 0.78; 95% CI, 0.45-1.34; P = .40), with unadjusted adherence rates of 53% (444 lesions) preimplementation vs 56% (469 lesions) postimplementation; however, the adjusted odds of adherence increased with calendar time (odds ratio, 1.68; 95% CI, 1.20-2.36; P = .003). All 3 implementation strategies were perceived as being feasible, acceptable, and appropriate; only the perception of audit-and-feedback appropriateness changed before vs after implementation (19 of 29 physicians [66%] vs 27 of 30 physicians [90%]; P = .03, Fisher exact test), with 20 physicians (67%) preferring reports quarterly. Conclusions and Relevance: In this quality improvement study, a multicomponent set of implementation strategies was not associated with increased use of short-course RT within an academic-community partnership. However, practice improved with time, perhaps owing to secular trends or physician awareness of the study. Audit-and-feedback was more appropriate than anticipated. Findings support the need to investigate optimal approaches for promoting evidence-based radiation practice across settings.

[Aprospective study of detection and clinical significance of bone marrow tumor cells in small cell lung cancer].

Objective: To investigate the detection of bone marrow tumor cells in small cell lung cancer (SCLC) patients and their relationship with clinical features, treatment response and prognosis. Methods: A total of 113patients with newly diagnosed SCLC from January 2018 to October 2022 at Beijing Chest Hospital were prospectively enrolled. Before treatment, bone marrow was aspirated and separately submitted for tumor cells detection by liquid-based cytology and disseminated tumor cells (DTCs) detection by the substrction enrichment and immunostaining fluorescence in situ hybridization (SE-iFISH) platform. The correlation between the detection results of the two methods with patients' clinical features and treatment response was evaluated by Chi-square. Kaplan-Meier method was applied to create survival curves and the Cox regression model was used for multivariate analysis. Results: The positive rate of bone marrow liquid-based cytology in SCLC was 15.93% (18/113). The liver and bone metastases rates were significantly higher (55.56% vs 11.58% for liver metastasis, P＜0.001; 77.78% vs 16.84% for bone metastasis, P＜0.001) and thrombocytopenia was more common (16.67% vs 2.11%, P=0.033) in patients with tumor cells detected in liquid-based cytology than those without detected tumor cells. As for SE-iFISH, DTCs were detected in 92.92% of patients (105/113), the liver and bone metastasis rates were significantly higher (37.93% vs 11.90% for liver metastasis, P=0.002; 44.83% vs 20.23 % for bone metastasis, P=0.010), and the incidence of thrombocytopenia was significantly increased (13.79% vs 1.19%, P=0.020) in patients with DTCs≥111 per 3 ml than those with DTCs＜111 per 3 ml. The positive rates of bone marrow liquid-based cytology in the disease control group and the disease progression group were 12.00% (12/100) and 46.15% (6/13), respectively, and the difference was statistically significant (P=0.002). However, the result of SE-iFISH revealed the DTCs quantities of the above two groups were 29 (8,110) and 64 (15,257) per 3 ml, and there was no statistical difference between the two groups (P=0.329). Univariate analysis depicted that the median progression-free survival (PFS) and median overall survival (OS) of liquid-based cytology positive patients were significantly shorter than those of tumor cell negative patients (6.33 months vs 9.27 months for PFS, P=0.019; 8.03 months vs 19.50 months for OS, P=0.019, P=0.033). The median PFS and median OS in patients with DTCs≥111 per 3 ml decreased significantly than those with DTCs＜111 per 3 ml (6.83 months vs 9.50 months for PFS, P=0.004; 11.2 months vs 20.60 months for OS, P=0.019). Multivariate analysis showed that disease stage (HR=2.806, 95%CI:1.499-5.251, P=0.001) and DTCs quantity detected by SE-iFISH (HR=1.841, 95%CI:1.095-3.095, P=0.021) were independent factors of PFS, while disease stage was the independent factor of OS (HR=2.538, 95%CI:1.169-5.512, P=0.019). Conclusions: Both bone marrow liquid-based cytology and SE-iFISH are clinically feasible. The positive detection of liquid-based cytology or DTCs≥111 per 3 ml was correlated with distant metastasis, and DTCs≥111 per 3 ml was an independent prognostic factor of decreased PFS in SCLC.

[Clinical characteristics and prognosis analysis of gastric cancer patients with bone metastasis].

Objectives: To investigate the clinical characteristics and prognosis of bone metastasis of gastric cancer, analyze the influencing factors of bone metastasis and the effects of different treatment methods, and provide a basis for early detection and treatment optimization of bone metastasis of gastric cancer. Methods: A total of 142 gastric cancer patients with bone metastasis admitted to the First Hospital of Lanzhou University from January 2011 to December 2021 were enrolled, including 60 cases of simple bone metastasis and 82 cases of bone metastasis combined with extraosseous metastasis. 142 patients with stage Ⅲgastric cancer without distant metastasis and 142 gastric cancer patients with visceral metastasis admitted to this hospital during the same period were also enrolled for comparison. Logistic regression analysis was used to determine the influencing factors of bone metastasis, and the Cox proportional hazards regression model was used to evaluate the influencing factors of overall survival (OS) of patients with bone metastasis. Results: Among the 142 patients with bone metastasis, poorly differentiated adenocarcinoma was the main type (123 cases), and 45 patients had simultaneous bone metastasis. Rib metastasis (100 cases), spine metastasis (88 cases), and pelvis metastasis (84 cases) were more common. A total of 110 patients had multiple bone metastasis, and 82 patients had extraosseous metastasis. Results of the stage Ⅲ gastric cancer group, the visceral metastasis group, the bone metastasis group, and the bone metastasis with extraosseous metastasis group were compared. There were significant differences in age, degree of differentiation, Borrmann type, alkaline phosphatase, lactate dehydrogenase, serum calcium, alanine aminotransferase, aspartate aminotransferase, creatine kinase isoenzyme, lymphocyte, hemoglobin, platelet, CEA, CA19-9, and CA724 (all P<0.05). Multivariate logistic regression analysis showed that Borrmann type was an independent protective factor of bone metastasis of gastric cancer (type 3: OR=0.07, 95%CI: 0.01-0.64, P=0.018). Alkaline phosphatase (OR=2.54, 95% CI: 1.07-6.01, P=0.034), serum calcium (OR=2.71, 95% CI: 1.15-6.41, P=0.023), creatine kinase isoenzyme (OR=16.33, 95% CI: 1.83-145.58, P=0.012), platelet (OR=10.08, 95% CI:1.89-53.85, P=0.007), and CA19-9 (OR=2.40, 95% CI: 1.14-5.05, P=0.021) were independent risk factors of bone metastasis of gastric cancer. The median OS of the stage Ⅲ gastric cancer group, the visceral metastasis group, the bone metastasis group, and the bone metastasis with extrabony group were 47, 13, 18, and 6 months, respectively, and the difference was statistically significant (P<0.001). The median OS of patients with bone metastasis only who underwent primary tumor surgery was 33 months, better than 6 months of patients without surgery (P=0.048). Multivariate Cox regression analysis showed that extraosseous metastasis (HR=2.45, 95% CI: 1.56-3.85, P<0.001) and decreased hemoglobin (HR=1.54, 95%CI: 1.02-2.34, P=0.042) were independent risk factors of OS of gastric cancer patients with bone metastasis. Conclusions: The prognosis of gastric cancer patients with bone metastasis alone is significantly better than that of other stage Ⅳ patients. For such patients, surgery on the primary site combined with chemotherapy after full evaluation may prolong the survival time.

TempEasy 3D Hydrogel Coculture System Provides Mechanistic Insights into Prostate Cancer Bone Metastasis.

Patients diagnosed with advanced prostate cancer (PCa) often experience incurable bone metastases; however, a lack of relevant experimental models has hampered the study of disease mechanisms and the development of therapeutic strategies. In this study, we employed the recently established Temperature-based Easy-separable (TempEasy) 3D cell coculture system to investigate PCa bone metastasis. Through coculturing PCa and bone cells for 7 days, our results showed a reduction in PCa cell proliferation, an increase in neovascularization, and an enhanced metastasis potential when cocultured with bone cells. Additionally, we observed increased cell proliferation, higher stemness, and decreased bone matrix protein expression in bone cells when cocultured with PCa cells. Furthermore, we demonstrated that the stiffness of the extracellular matrix had a negligible impact on molecular responses in both primary (PCa cells) and distant malignant (bone cells) sites. The TempEasy 3D hydrogel coculture system is an easy-to-use and versatile coculture system that provides valuable insights into the mechanisms of cell-cell communication and interaction in cancer metastasis.

Diagnostic accuracy of contrast-enhanced computed tomography in assessing bone invasion in patients with oral squamous cell carcinoma.

OBJECTIVES: This study aimed to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) in detecting bone invasion in oral squamous cell carcinoma (OSCC) patients and to explore clinicopathological factors associated with its reliability. MATERIALS AND METHODS: 417 patients underwent preoperative contrast-enhanced CT followed by radical surgery. The presence or absence of bone invasion served as the outcome variable, with histopathologic examination of the resection specimen considered the gold standard. Statistical analyses, comprising correlation analyses and the determination of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were conducted. RESULTS: CT exhibited 76.85% sensitivity, 82.20% specificity, 47.14% PPV, and 89.67% NPV. False-positive and false-negative rates were 11.27% and 5.99%, respectively. Artifacts affected assessment in 44 patients, but not in those with bone invasion. Tumor size, depth of invasion (DOI), tumor localization at the upper jaw, lymphatic invasion, and perineural invasion correlated with incorrect identification of bone invasion (Chi-square, p < 0.05). CONCLUSIONS: Despite utilizing thin-section CT, notable false-positive and false-negative results persisted. Patients with T3 tumors, DOI ≥ 10 mm, or upper jaw tumors are at higher risk for misidentification of bone invasion. Combining multiple methods may enhance diagnostic accuracy, and the integration of artificial intelligence or tracking electrolyte disturbances by tumor depth profiling shows promise for further assessment of bone invasion before histopathology. CLINICAL RELEVANCE: Surgeons should consider these insights when planning tumor resection. Supplementary imaging may be warranted in cases with high risk factors for misidentification. Further methodological advancements are crucial for enhancing diagnostic precision.

Manubriectomy made easy.

Bone metastasis is the most common form of distant metastasis encountered within the breast cancer population. Surgical resection of bone metastases is a curative treatment option in patients who present with an isolated solitary lesion and no other associated disease. This decision is typically made following a multidisciplinary discussion. Patients can also be put forward for surgical excision of bone metastases following inadequate response to chemotherapy or radiotherapy.  With tumours located in the manubrium of the sternum, surgery serves not only to resect the bone metastasis but to provide suitable chest wall reconstruction. The goal of this approach is to maintain the structural and bony stability of the chest wall as well as that of associated structures, e.g. rib insertion or articulation of the shoulder girdle. A widely utilized approach involves excising the area of metastasis within the manubrium followed by implanting a bone cement prosthesis. Titanium plates are used to fix the bone prosthesis to the sternal body inferiorly and to the remainder of the manubrium superiorly.  We present a step-by-step video tutorial for performing a lower hemi-manubriectomy in a patient with triple-negative breast cancer. Our goal is to describe the fundamental principles and surgical techniques used to perform this procedure followed by the postoperative outcomes.

Single-cell and spatial transcriptomics reveal metastasis mechanism and microenvironment remodeling of lymph node in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor and is highly prone to metastasis. OS can metastasize to the lymph node (LN) through the lymphatics, and the metastasis of tumor cells reestablishes the immune landscape of the LN, which is conducive to the growth of tumor cells. However, the mechanism of LN metastasis of osteosarcoma and remodeling of the metastatic lymph node (MLN) microenvironment is not clear. METHODS: Single-cell RNA sequencing of 18 samples from paracancerous, primary tumor, and lymph nodes was performed. Then, new signaling axes closely related to metastasis were identified using bioinformatics, in vitro experiments, and immunohistochemistry. The mechanism of remodeling of the LN microenvironment in tumor cells was investigated by integrating single-cell and spatial transcriptomics. RESULTS: From 18 single-cell sequencing samples, we obtained 117,964 cells. The pseudotime analysis revealed that osteoblast(OB) cells may follow a differentiation path from paracancerous tissue (PC) → primary tumor (PT) → MLN or from PC → PT, during the process of LN metastasis. Next, in combination of bioinformatics, in vitro and in vivo experiments, and immunohistochemistry, we determined that ETS2/IBSP, a new signal axis, might promote LN metastasis. Finally, single-cell and spatial dissection uncovered that OS cells could reshape the microenvironment of LN by interacting with various cell components, such as myeloid, cancer-associated fibroblasts (CAFs), and NK/T cells. CONCLUSIONS: Collectively, our research revealed a new molecular mechanism of LN metastasis and clarified how OS cells influenced the LN microenvironment, which might provide new insight for blocking LN metastasis.

Tebentafusp in the treatment of metastatic uveal melanoma - the first patient treated in the Czech Republic.

BACKGROUND: Uveal melanoma is a rare cancer, in which metastases occur in approximately one half of cases. In metastatic disease, the prognosis is unfavorable and the median of survival does not exceed 6 months. Effective treatment options were very limited up to date. Tebentafusp is a bispecific fusion protein, which as the first drug proved efficacy in uveal melanoma. CASE: The patient was referred for suspected uveal melanoma of the left eye. She was treated for Hodgkin's disease in the past. Primarily, the tumor was treated by radiosurgery with radiotherapy of a small lesion of the vertebral body. However, later the patient had to undergo bulbus enucleation with confirmation of a large tumor category pT4b. PET/CT revealed metastases of the bones and the liver; simultaneously, haplotype A*02: 01 was confirmed. The patient underwent radiotherapy of the sternum and later, after confirmation of payment from the health insurance company, she started treatment with tebentafusp. The first three doses were administered during admission to the hospital, with a need to treat cytokine release syndrome by corticosteroids. Later, the administration was performed in an out-patient regimen, without complications, except for a transient elevation of transaminases. The first CT restaging confirmed stable disease; however, the second restaging confirmed a new osteolytic lesion in the processus of Th11. Because of progression, the treatment with tebentafusp was withdrawn after 6 months. Unfortunately, the lesion could not be treated by radiotherapy. Two months later, the patient was urgently admitted to the hospital because of right-sided hemiplegia; MRI revealed bleeding metastatic lesion in the brain stem. CONCLUSION: In this case report, we present the case of the first patient treated with this drug in the Czech Republic.

Interrogating Estrogen Signaling Pathways in Human ER-Positive Breast Cancer Cells Forming Bone Metastases in Mice.

Breast cancer bone metastases (BMET) are incurable, primarily osteolytic, and occur most commonly in estrogen receptor-α positive (ER+) breast cancer. ER+ human breast cancer BMET modeling in mice has demonstrated an estrogen (E2)-dependent increase in tumor-associated osteolysis and bone-resorbing osteoclasts, independent of estrogenic effects on tumor proliferation or bone turnover, suggesting a possible mechanistic link between tumoral ERα-driven osteolysis and ER+ bone progression. To explore this question, inducible secretion of the osteolytic factor, parathyroid hormone-related protein (PTHrP), was utilized as an in vitro screening bioassay to query the osteolytic potential of estrogen receptor- and signaling pathway-specific ligands in BMET-forming ER+ human breast cancer cells expressing ERα, ERß, and G protein-coupled ER. After identifying genomic ERα signaling, also responsibility for estrogen's proliferative effects, as necessary and sufficient for osteolytic PTHrP secretion, in vivo effects of a genomic-only ER agonist, estetrol (E4), on osteolytic ER+ BMET progression were examined. Surprisingly, while pharmacologic effects of E4 on estrogen-dependent tissues, including bone, were evident, E4 did not support osteolytic BMET progression (vs robust E2 effects), suggesting an important role for nongenomic ER signaling in ER+ metastatic progression at this site. Because bone effects of E4 did not completely recapitulate those of E2, the relative importance of nongenomic ER signaling in tumor vs bone cannot be ascertained here. Nonetheless, these intriguing findings suggest that targeted manipulation of estrogen signaling to mitigate ER+ metastatic progression in bone may require a nuanced approach, considering genomic and nongenomic effects of ER signaling on both sides of the tumor/bone interface.

Case report: Sintilimab combined with anlotinib as neoadjuvant chemotherapy for metastatic bone tumor resection in patients with PSC.

Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small-cell lung cancer (NSCLC), which is resistant to chemotherapy and radiotherapy with a poor prognosis. PSC is highly malignant and is prone to recurrence even after surgery. The programmed death-ligand 1 (PD-L1) tumor cell proportion score (TPS) 5%, TERT and TP53 gene mutations were detected in this patient accompanied by multiple metastatic sites. The anlotinib is a novel multitarget tyrosine kinase inhibitor (TKI) that could be effective for advanced NSCLC and some sarcoma patients. Limited clinical trials and case reports have shown that PSC patients with gene mutations and PD-L1 expression have good responses to multitarget antiangiogenic drug and immune checkpoint inhibitors (ICIs). In this article, we reported a case with metastatic PSC diagnosed by Computed Tomography (CT)-guided needle biopsy treated with immunotherapy combined with antiangiogenic drugs as a neoadjuvant chemotherapy (NACT). PSC is controlled and the patient achieves successfully limb salvage treatment by surgical resection. Therefore, targeted therapy and immunotherapy can provide sufficient surgical opportunities for limb salvage in the treatment of metastatic PSC patients. Case summary: A 69-year-old male diagnosed with malignant bone tumor in the proximal femur was admitted to our hospital in June 2022 with recurrent fever as well as swelling and pain in the left thigh for twenty days. The initial computed tomography (CT) scan of the chest showed a pulmonary cavity (20 mm × 30 mm) and scattered lung masses. Subsequently, he underwent a CT-guided needle biopsy to distinguish the essence of osteolytic bone destruction and soft tissue mass in the left proximal femur which showed metastatic sarcomatoid carcinoma histology. Genetic testing revealed TERT c.-124C mutation (abundance 8.81%), TP53 p.R342 mutation (abundance 11.35%), tumor mutational burden (TMB) 7.09 muts/Mb, microsatellite stability (MSS), and PD-L1 (SP263) TPS 5% were also detected. The patient was tentatively treated with a combination of antiangiogenic drug and PD-1 inhibitor. After one course, the tumor volume significantly reduced in magnetic resonance imaging (MRI) and pathological fracture occurred in the femur after combined treatment. The patient received proximal femoral tumor resection and prosthesis replacement after defervescence. Sequentially sintilimab with anlotinib were administered for over 1 year. Finally, the local tumor was well controlled, and no obvious drug-related adverse reactions were observed. The lesions in the lung remained in partial response (PR) for more than 16 months and complete response (CR) of metastatic tumor in the proximal femur was observed through imaging examinations. Conclusion: This is the first reported case of a metastatic PSC in femur showing a favorable response to the treatment consisting of anlotinib combined with sintilimab. This case suggests that antiangiogenic therapy combined with immunotherapy may benefit patients with metastatic PSC in the preoperative adjuvant therapy for limb salvage.

Development of a New Focal Mouse Model of Bone Metastasis in Renal Cell Carcinoma.

BACKGROUND/AIM: Developing animal models of bone metastasis in renal cell carcinoma (RCC) is challenging as immunodeficient mice are required. The aim of this study was to develop a simple immune model of RCC bone metastasis. MATERIALS AND METHODS: RENCA tumor cells were injected into the right femurs of BALB/c mice. Sixty mice were grouped into each twenty-mouse group according to the tumor cell concentration, and the presence or absence and extent of bone metastasis in the total length of the femur were compared using hematoxylin and eosin staining of the excised tissues. RESULTS: Bone metastasis was significantly higher in the high concentration group than in the other groups (p<0.05), with 10 mice developing bone metastasis at two weeks and nine mice developing bone metastasis at three weeks. The extent of bone metastasis was significantly greater in the high concentration group than in the other groups (p<0.05). Multiple logistic regression analysis was performed to examine the factors influencing bone metastasis, and only the high concentration was a significant factor (p<0.05). CONCLUSION: We developed a normal immunity mouse model of local bone metastasis from RCC. This model could prove valuable for research into the treatment of bone metastases in RCC.