Management of Sacrococcygeal Chordoma: A Systematic Review and Meta-analysis of Observational Studies

Chordoma: Genetics and Contemporary Management

Chordomas, arising from notochord remnants, are rare neoplasms with aggressive growth patterns despite their histologically low-grade nature. This review explores their embryological origins, molecular markers like brachyury, and genetic alterations driving pathogenesis. Diagnosis relies on advanced imaging and biopsy confirmation due to overlapping features with chondrosarcoma. The WHO classification distinguishes conventional, dedifferentiated, and poorly differentiated chordomas, each with distinct prognostic implications. Recent genomic analyses uncovered recurrent mutations in PI3K signaling pathways and chromatin remodeling genes, informing prognostic models. Surgery remains the cornerstone of treatment, though adjuvant radiation complements surgical resection. Although chordomas are generally considered refractory to medical therapy, emerging targeted molecular strategies show potential promise in ongoing trials. This review aims to provide a concise yet comprehensive overview of chordomas, guiding clinicians in diagnosis, treatment, and prognostication for improved patient outcomes.

Imaging Assessment of the Efficacy of Chemotherapy in Primary Malignant Bone Tumors: Recent Advances in Qualitative and Quantitative Magnetic Resonance Imaging and Radiomics

Recent studies have shown that MRI demonstrates promising results for evaluating the chemotherapy efficacy in bone sarcomas. This article reviews current methods for evaluating the efficacy of malignant bone tumors and the application of MRI in this area, and emphasizes the advantages and limitations of each modality. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

A correlation analysis of sacrococcygeal chordoma imaging and clinical characteristics with the prognostic factors

Objective

To investigate the imaging and clinical risk factors related to the postoperative recurrence of sacrococcygeal chordoma.

Methods

63 patients of sacrococcygeal chordoma proved by operation and pathology in our hospital from January 2009 to December 2019 were retrospectively analyzed in the related factors of imaging manifestations, pathological type, and extent of surgical resection. The recurrence of sacrococcygeal chordoma was followed up. Univariate Kaplan-Meier survival analysis and multivariate Cox regression analysis were used to analyze the related factors of recurrence.

Results

On plain radiographs and CT scans, chordoma primarily manifested as osteolytic bone loss and uneven soft tissue mass, with typical calcification or ossification (56.1 percent). Numerous chunk nodules with clearly high signal levels and short signal intervals were seen as the “pebble” in MRI characteristics on T2WI. The follow-up period ranged from 20 to 130 months, with a median time of 47.5 months. There were 14 recurrences (22. 2%) during the follow-up period. 13 patients with recurrence underwent surgery again, and 5 of them recurred after surgery (recurrence time range 3 to 97 months, median 38. 5 months). 6 (42.8%), 8 (57. 1%), and 13 (92. 9%) of the 14 patients with recurrence recurred within 2, 3, and 5 years after surgery, respectively. Univariate Kaplan-Meier survival analysis showed that occurred with local infiltration, Low differentiated chordoma, partial resection had a high postoperative recurrence rate, and all differences were statistically significant (P<0.05). Multi-factor Cox regression analysis showed whether local infiltration occurred and the degree of tumor resection were independent risk factors for tumor recurrence.

Conclusion

Sacrococcygeal chordoma has a high tendency of recurrence, and the likelihood of recurrence is higher in tumor occurred with local infiltration, non-complete tumor resection and low differentiated chordoma, which can be considered to shorten the review cycle and complete tumor resection as much as possible during surgery.

Management of chordoma of the sacrum and mobile spine

Chordoma is a very rare, poorly known malignancy, with slow progression, mainly located in the sacrum and spine. All age groups may be affected, with a diagnostic peak in the 5th decade of life. Clinical diagnosis is often late. Histologic diagnosis is necessary, based on percutaneous biopsy. Specific markers enable diagnosis and prediction of response to novel treatments. New radiation therapy techniques can stabilize the tumor for 5 years in inoperable patients, but en-bloc resection is the most effective treatment, and should be decided on after a multidisciplinary oncology team meeting in an expert reference center. The type of resection is determined by fine analysis of invasion. According to the level of resection, the patients should be informed and prepared for the expected vesico-genito-sphincteral neurologic sequelae. In tumors not extending above S3, isolated posterior resection is possible. Above S3, a double approach is needed. Anterior release of the sacrum is performed laparoscopically or by robot; resection uses a posterior approach. Posterior wall reconstruction is performed, with an associated flap. Spinopelvic stabilization is necessary in trans-S1 resection. Total or partial sacrectomy shows high rates of complications: intraoperative blood loss, infection or mechanical issues. Neurologic sequelae depend on the level of root sacrifice. No genital-sphincteral function survives S3 root sacrifice. Patient survival depends on initial resection quality and the center's experience. Immunotherapy is an ongoing line of research.

[Update and interpretation of 2021 National Comprehensive Cancer Network (NCCN) "Clinical Practice Guidelines for Bone Tumors"]

The incidence of primary malignant bone tumors is low, and clinical cognition is insufficient. The establishment of diagnostic criteria is of great significance for prognosis of tumors. National Comprehensive Cancer Network (NCCN) regularly publishes "Clinical Practice Guidelines for Bone Tumors" to summarize the latest treatment progress of bone tumors. In the latest version of the guidelines released in November 2020, surgery is the main treatment for chondrosarcoma, chordoma, and giant cell tumor of bone, which can be combined with radiotherapy or targeted therapy. Ewing's sarcoma and osteosarcoma are treated by surgery combined with chemotherapy. Immunotherapy can be used to treat high-grade undifferentiated pleomorphic sarcoma. For recurrent tumors, surgery combined with radiotherapy, chemotherapy, and/or targeted therapy can be used for control. The guidelines provide a reference for the standard treatment of bone tumors.

Chordoma: Current status, problems, and future directions

Chordoma is a rare tumor that occurs along the axial spine in pediatrics and adults, with an incidence of approximately 350 cases per year in the United States. While typically described as slow-growing, many patients will eventually develop loco-regional relapse or metastatic disease with few treatment options. Despite numerous efforts over the last 10+ years, effective treatments for patients are lacking. As subtypes of chordoma are identified and described in more detail, further knowledge regarding the natural history of each type, tumor location, age differences, genomic variability, and an overall better understanding of chordoma may be the key to developing meaningful clinical trials and effective therapies for patients with chordoma.

Critically Low Confidence in the Results Produced by Spine Surgery Systematic Reviews: An AMSTAR-2 Evaluation From 4 Spine Journals

STUDY DESIGN

A systematic cross-sectional survey of systematic reviews (SRs).

OBJECTIVE

To evaluate the methodological quality of spine surgery SRs published in 2018 using the updated AMSTAR 2 critical appraisal instrument.

METHODS

We identified the PubMed indexed journals devoted to spine surgery research in 2018. All SRs of spine surgical interventions from those journals were critically appraised for quality independently by 2 reviewers using the AMSTAR 2 instrument. We calculated the percentage of SRs achieving a positive response for each AMSTAR 2 domain item and assessed the levels of confidence in the results of each SR.

RESULTS

We identified 28 SRs from 4 journals that met our criteria for inclusion. Only 49.5% of the AMSTAR 2 domain items satisfied the AMSTAR 2 criteria. Critical domain items were satisfied less often (39.1%) compared with noncritical domain items (57.3%). Domain items most poorly reported include accounting for individual study risk of bias when interpreting results (14%), list and justification of excluded articles (18%), and an a priori establishment of methods prior to the review or registered protocol (18%). The overall confidence in the results was rated "low" in 2 SRs and "critically low" in 26.

CONCLUSIONS

The credibility of a SR and its value to clinicians and policy makers are dependent on its methodological quality. This appraisal found significant methodological limitations in several critical domains, such that the confidence in the findings of these reviews is "critically low."

Genetic landscape and ligand-dependent activation of sonic hedgehog-Gli1 signaling in chordomas: a novel therapeutic target

Chordoma, a rare neoplasm derived from intraosseous notochordal remnants, is unresponsive to conventional chemotherapy and radiotherapy. Sonic Hedgehog (Shh) is a crucial fetal notochord-secreted morphogen that directs notochordal development. The aim of this study was to determine the functional roles and therapeutic potential of Shh-Gli1 signaling in chordomas. Tissue samples and clinical profiles were collected from 42 patients with chordoma. The chordoma cell lines U-CH1 and MUG-Chor1 were used for functional experiments. Shh-Gli1 signaling pathway genetic alterations were screened, and the functions of the identified novel variants were analyzed using in silico analyses, real-time quantitative PCR, and minigene assays. Ligand-dependent Shh-Gli1 signaling activation was assessed using single- and dual-label immunostaining, western blot analysis, and a Shh-responsive Gli-luciferase reporter assay. The small-molecule inhibitor vismodegib was used to target Shh-Gli1 signaling in vitro and in vivo. Overall, 44 genetic alterations were identified, including four novel variants (c.67_69dupCTG in SMO, c.-6_-4dupGGC and c.3306 + 83_3306 + 84insG in PTCH1, and c.183-67_183-66delinsA in SUFU). Shh, PTCH1, SMO, SUFU, and Gli1 were extensively expressed in chordomas, and higher Gli1 expression correlated with poorer prognosis. A luciferase reporter assay and dual-label immunostaining indicated the occurrence of juxtacrine ligand-dependent Shh-Gli1 signaling activation. Vismodegib significantly inhibited cell proliferation and induced apoptosis and G1/S cell cycle arrest. In vivo investigation demonstrated that vismodegib effectively inhibited chordoma xenograft growth. This current preclinical evidence elucidates the therapeutic potential of Shh-Gli1 signaling pathway targeting for chordoma treatment. Vismodegib may be a promising targeted agent, and further clinical trials are warranted.

Clinicopathological and Prognostic Characteristics in Extra-Axial Chordomas: An Integrative Analysis of 86 Cases and Comparison With Axial Chordomas

BACKGROUND

Currently, clinical characteristics and prognostic factors of extra-axial chordoma (EAC) remain poorly understood.

OBJECTIVE

To characterize clinicopathological characteristics in a large EAC cohort and investigate their correlation with survival. We also attempted to compare these outcomes with axial chordoma (AC).

METHODS

Medline and Embase searches (from inception to February 28, 2018) were conducted to identify eligible studies as per predefined criteria. The local database at our center was also retrospectively reviewed to include additional patients.

RESULTS

Forty-three studies from the literature and 86 patients from our local institute were identified, resulting in a total of 86 EAC patients and 75 AC patients for analysis. Overall, EAC had similar characteristics to AC, except for having higher CAM5.2 expression, common lobular growth pattern, and better prognosis. Whereas wide surgical resection was consistently associated with favorable survival in both EAC and AC cohorts on univariate analyses, most parameters showed differential prognostic implications between the 2 groups. Significant prognostic factors for local recurrence-free survival on multivariate analysis included type of surgery in both cohorts and tumor Brachyury expression and adjuvant radiotherapy in AC cohort. Multivariate analysis of overall survival demonstrated that type of surgery, tumor Brachyury expression, and duration of symptoms were significant predictors in the AC cohort, whereas none of the analyzed parameters were predictive of overall survival for the EAC group.

CONCLUSION

These data suggest potentially distinct biological behaviors between EAC and AC and may provide useful information to better understand the prognostic characteristics and improve the outcome prediction of EAC patients.

Outcomes, Prognostic Factors and Salvage Treatment for Recurrent Chordoma After Pencil Beam Scanning Proton Therapy at the Paul Scherrer Institute

AIMS

The outcome of chordoma patients with local or distant failure after proton therapy is not well established. We assessed the disease-specific (DSS) and overall survival of patients recurring after proton therapy and evaluated the prognostic factors affecting DSS.

MATERIALS AND METHODS

A retrospective analysis was carried out of 71 recurring skull base (n = 36) and extracranial (n = 35) chordoma patients who received adjuvant proton therapy at initial presentation (n = 42; 59%) or after post-surgical recurrence (n = 29; 41%). The median proton therapy dose delivered was 74 GyRBE (range 62-76). The mean age was 55 ± 14.2 years and the male/female ratio was about one.

RESULTS

The median time to first failure after proton therapy was 30.8 months (range 3-152). Most patients (n = 59; 83%) presented with locoregional failure only. There were only 12 (17%) distant failures, either with (n = 5) or without (n = 7) synchronous local failure. Eight patients (11%) received no salvage therapy for their treatment failure after proton therapy. Salvage treatments after proton therapy failure included surgery, systemic therapy and additional radiotherapy in 45 (63%), 20 (28%) and eight (11%) patients, respectively. Fifty-three patients (75%) died, most often from disease progression (47 of 53 patients; 89%). The median DSS and overall survival after failure was 3.9 (95% confidence interval 3.1-5.1) and 3.4 (95% confidence interval 2.5-4.4) years, respectively. On multivariate analysis, extracranial location and late failure (≥31 months after proton therapy) were independent favourable prognostic factors for DSS.

CONCLUSION

The survival of chordoma patients after a treatment failure following proton therapy is poor, particularly for patients who relapse early or recur in the skull base. Although salvage treatment is administered to most patients with uncontrolled disease, they will ultimately die as a result of disease progression in most cases.

A four-factor immune risk score signature predicts the clinical outcome of patients with spinal chordoma

BACKGROUND

Currently, the measurement of immune cells in previous studies is usually subjective, and no immune-based prognostic model has been established for chordoma. In this study, we sought to simultaneously measure tumor-infiltrating lymphocyte (TIL) subtypes in chordoma samples using an objective method and develop an immune risk score (IRS) model for survival prediction.

METHODS

Multiplexed quantitative immunofluorescence staining was used to determine the TIL levels in the tumoral and stromal subareas of 114 spinal chordoma specimens (54 in the training and 60 in the validation cohort) for programmed death-1 (PD-1), CD3, CD8, CD20 (where CD is cluster of differentiation), and FOXP3. Flow cytometry was performed to validate the immunofluorescence assay for lymphocyte measurement on an additional five fresh chordoma specimens. Subsequently, the IRS model was built using the least absolute shrinkage and selection operator (LASSO) Cox regression method.

RESULTS

Flow cytometry and quantitative immunofluorescence showed similar lymphocytic percentages and TIL subpopulation proportions in the fresh tumor specimens. With the training data, the LASSO model identified four immune features for IRS construction: tumoral FOXP3, tumoral PD-1, stromal FOXP3, and stromal CD8. In both cohorts, a high IRS was significantly associated with tumoral programmed cell death-1 ligand 1 expression, Enneking inappropriate tumor resection, and surrounding muscle invasion by tumor. Multivariate Cox regression and stratified analysis in the two cohorts revealed that the IRS was an independent predictor and could effectively separate patients with similar Enneking staging into different risk subgroups, with significantly different survival rates. Further receiver operating characteristic analysis found that the IRS classifier had a better prognostic value than the traditional clinicopathological factors and compensated for the deficiency of Enneking staging for outcome prediction. More importantly, a nomogram based on the IRS and clinical predictors showed adequate performance in estimating disease recurrence and survival of patients.

CONCLUSIONS

These data support the use of the IRS signature as a reliable prognostic tool in spinal chordoma and may facilitate individualized therapy decision making for patients.

A Comparative Study Between Traditional Microscopic Surgeries and Endoscopic Endonasal Surgery for Skull Base Chordomas

BACKGROUND

Skull base chordomas (SBCs) are rare clinically aggressive neoplasms, developing local recurrences after surgical resection. Although SBCs have traditionally been resected by craniotomy or microscopic transsphenoidal surgery (TSS), the recent development of the endoscopic endonasal approach (EEA) has revolutionized treatment strategies through minimally invasive techniques. This study aimed to evaluate clinical outcomes after traditional microsurgeries or EEAs for SBCs.

METHODS

The present retrospective study investigated 66 patients with primary SBCs who underwent surgery between 1977 and 2019. Resection was performed via EEA in 17 cases, craniotomy in 23, transoral approach in 8, TSS in 12, staged surgery in 4, and others in 2. The median follow-up period for progression-free survival (PFS) was 19.5 months.

RESULTS

There were no significant differences in preoperative tumor volume or resection rate among these approaches. The incidence of postoperative cranial nerve palsy was significantly lower in EEA than that in craniotomy (P < 0.05). Although total resection was observed in 4 cases of EEA expanding into the superior and inferior part of the clivus, no cases of transoral approach or TSS achieved total resection for both parts. No significant difference in PFS was found among these approaches. Multivariate analysis showed that being female and the absence of radiotherapy were significantly associated with shorter PFS (P < 0.05 and P < 0.001, respectively). The resection rate was not associated with PFS.

CONCLUSIONS

EEA is a less invasive surgical approach for SBCs. The development of surgical instruments and postoperative radiotherapy will further improve patients' outcomes.

Acquired Idiopathic Stiffness After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Stiffness is a common reason for suboptimal clinical outcomes after primary total knee arthroplasty (pTKA). There is a lack of consensus regarding its definition, which is often conflated with its histopathologic subcategory-i.e., arthrofibrosis. There is value in refining the definition of acquired idiopathic stiffness in an effort to select for patients with arthrofibrosis. We conducted a systematic review and meta-analysis to establish a consensus definition of acquired idiopathic stiffness, determine its prevalence after pTKA, and identify potential risk factors for its development.

METHODS

MEDLINE, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Scopus databases were searched from 2002 to 2017. Studies that included patients with stiffness after pTKA were screened with strict inclusion and exclusion criteria to isolate the subset of patients with acquired idiopathic stiffness unrelated to known extrinsic or surgical causes. Three authors independently assessed study eligibility and risk of bias and collected data. Outcomes of interest were then analyzed according to age, sex, and body mass index (BMI).

RESULTS

In the 35 included studies (48,873 pTKAs), the mean patient age was 66 years. In 63% of the studies, stiffness was defined as a range of motion of <90° or a flexion contracture of >5° at 6 to 12 weeks postoperatively. The prevalence of acquired idiopathic stiffness after pTKA was 4%, and this did not differ according to age (4%, I = 95%, among patients <65 years old and 5%, I = 96%, among those ≥65 years old; p = 0.238). The prevalence of acquired idiopathic stiffness was significantly lower in males (1%, I = 85%) than females (3%, I = 95%) (p < 0.0001) as well as in patients with a BMI of <30 kg/m (2%, I = 94%) compared with those with a BMI of ≥30 kg/m (5%, I = 97%) (p = 0.027).

CONCLUSIONS

Contemporary literature supports the following definition for acquired idiopathic stiffness: a range of motion of <90° persisting for >12 weeks after pTKA in patients in the absence of complicating factors including preexisting stiffness. The mean prevalence of acquired idiopathic stiffness after pTKA was 4%; females and obese patients were at increased risk.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Carbon Ion Radiotherapy for Patients with Extracranial Chordoma or Chondrosarcoma - Initial Experience from Shanghai Proton and Heavy Ion Center

Purpose: The purpose of this study was to evaluate the outcomes of patients with extracranial chordoma or chondrosarcoma treated by carbon ion radiotherapy (CIRT).

Patients and methods: Between May 2015 and April 2018, 21 consecutive patients with chordoma (n=16) or chondrosarcoma (n=5) treated by CIRT at Shanghai Proton and Heavy Ion Center (SPHIC) were enrolled. The local control (LC), progression free survival (PFS), and overall survival (OS) rates were estimated using the Kaplan-Meier method. Association between each of the candidate prognostic factors and the estimated LC, PFS or OS was tested using the log rank test.

Results: The median gross tumor volume (GTV) was 512.7 ml (range, 142.6-2893.0 ml). The median prescription dose was 69 gray equivalent (GyE) (range, 57-80 GyE). After a median follow-up of 21.8 months (range, 7.2-39.2 months), the 1-year LC, PFS, and OS were 93.8%, 88.4%, and 100%, respectively, whereas the 2-year LC, PFS, and OS were 85.2%, 80.4%, and 100%, respectively. A univariate analysis revealed that age, metal implant status, treatment status, sex, dose, and GTV were not significant prognostic factors for LC, PFS or OS. No grade 2 or higher early and late toxicities were observed within the follow-up.

Conclusion: The results of this retrospective study are encouraging. Patients with extracranial chordoma or chondrosarcoma treated by CIRT in our center achieved a favorable shot-term outcome, without developing severe acute or late adverse events. The long-term results deserve further investigation, even in a prospective randomized trial.