3D-printed hemipelvic endoprosthesis is an emerging solution for personalized limb-salvage reconstruction after periacetabular tumor resection. Further clinical studies are still required to report its surgical characteristics, outcomes, benefits and drawbacks. Sixteen consecutive patients underwent periacetabular tumor wide resection and pelvic reconstruction with a 3D-printed hemipelvic endoprosthesis from 2018 to 2021. The surgical characteristics and outcomes are described. The mean follow-up duration was 17.75 months (range, 6 to 46 months). Five patients underwent surgery for type I + II resection and reconstruction, seven for type II + III resection and reconstruction, three for type II resection and reconstruction, and one for type I + II + IV resection and reconstruction. The incidence of postoperative complication was 12.5% (2/16) for deep venous thrombosis (DVT), 12.5% (2/16) for pneumonia, and 12.5% (2/16) for would deep or superficial infection. During follow-up, two patients (12.5%) suffered hip dislocation and underwent revision surgery. CT demonstrated an obvious prosthetic porous structure–bone fusion after follow-up of at least 6 months. At the final follow-up, 12 lived with no evidence of disease while four lived with disease; no patients experienced pain; and 15 had independent ambulation, with a mean Musculoskeletal Tumor Society (MSTS) score of 85.8% (range, 26.7% to 100%). 3D-printed hemipelvic endoprosthesis facilitates wide resection of periacetabular tumor and limb-salvage reconstruction, thus resulting in good oncological and functional outcomes. The custom-made nature is able to well mimic the skeletal anatomy and microstructure and promote osseointegration. Perioperative complications and rehabilitation exercise still need to be stressed for this engineering technology-assisted major orthopedic surgery.

Lung cancer (LC), prostate cancer (PC), and breast cancer (BC) are the three most prevalent cancers that lead to bone metastasis (BoM). In this study, we conducted an integrated analysis of single-cell transcriptomic data from the primary tumors and BoM across PC, LC, and BC. We discover a novel subtype of tumor-associated macrophages (TAMs) that are positive both for matrix metalloproteinase 19 (MMP19) and receptor activator of nuclear factor-κB (RANK) expression (MMP19⁺ RANK⁺ TAMs). MMP19⁺ RANK⁺ TAMs demonstrate an increased level of M2 polarization and act as a critical driving factor for LC-BoM. MMP19⁺ RANK⁺ TAMs are organized in a ring-like arrangement surrounding the tumor nests, constructing a barrier structure that impedes the infiltration of CD8⁺ T cells into the tumor core in LC-BoM. RANKL inhibitor Denosumab has been shown to effectively reduce the level of M2 polarization, decrease the population of MMP19⁺ RANK⁺ TAMs, and disrupt their barrier structure. Denosumab facilitates the infiltration of CD8⁺ T cells into the interior of LC-BoM tissues. Based on this mechanism, we observed in both clinical cohorts and preclinical models that RANKL inhibitor can enhance the efficacy of immunotherapy in treating LC-BoM.

Background Synchronous bone metastases (BM) have a notable impact on the survival rates of patients across various cancer types. While primary tumor surgery (PTS) has shown potential benefits, its impact across different cancers and patient subgroups needs further clarification. This study aimed to investigate the survival benefits of PTS across various cancer types. Methods This retrospective cohort study analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database, covering 53,015 patients diagnosed with BM from 2010 to 2019. Propensity score matching (PSM) was performed to reduce baseline imbalance. Overall survival (OS) and cancer-specific survival (CSS) were evaluated using Kaplan–Meier analysis and Cox proportional hazards regression. Results PTS substantially improved overall and cancer-specific survival in patients with lung, kidney, breast and bladder cancers. All surgical modalities benefited breast and renal cancer survival. In prostate cancer, PTS produced no overall survival gain; survival varied by surgery type, being better after prostatectomy and worse with local resection. For liver cancer, PTS improved cancer-specific but not overall survival, and the small matched cohort necessitates circumspect interpretation. Conclusion The findings indicate that PTS can significantly enhance survival in selected patients with BM, particularly in lung, kidney, breast, and bladder cancers. Tailoring surgical approaches based on individual cancer type and patient characteristics is crucial to optimizing treatment outcomes. Further studies are required to validate these results and expand the understanding of PTS in cancer management.