A review of the surgical management of sacral chordoma

MicroRNA‑1224 inhibits cell proliferation by downregulating CBX3 expression in chordoma

MicroRNAs (miRNAs/miRs) have abnormal expression in numerous tumors and are closely related to tumor development and resistance to radiotherapy and chemotherapy. However, there are few studies assessing the role and mechanism of miRNA in chordoma. The sequencing data of three pairs of chordoma and notochord tissues from the GSE56183 dataset were analyzed in the present study. Cell proliferation was assessed in vitro using Cell Counting Kit-8. Bioinformatics analysis and the dual luciferase reporter assay were used to evaluate the regulatory relationship between miR-1224 and chromobox 3 (CBX3) in chordoma. The results demonstrated that miR-1224 had a significantly lower expression level in chordoma tissues and cell lines. Overexpression of miR-1224 inhibited proliferation in the chordoma cells, while the knockdown of miR-1224 promoted proliferation of the chordoma cells. Bioinformatics analysis and the dual luciferase reporter assay confirmed that CBX3 was a direct target gene of miR-1224 and that miR-1224 induced the proliferation of chordoma cells through the inhibition of CBX3. In summary, miR-1224 reduced the proliferation of chordoma cells through inhibition of CBX3, which provides a theoretical basis for selecting a novel therapeutic target for chordoma.

Hypoxia-Inducible Factor-1α (HIF-1α) as a Factor to Predict the Prognosis of Spinal Chordoma

STUDY DESIGN

Retrospective study.

OBJECTIVE

In this study, the authors explore the potential relationship between hypoxia inducible factor-1α (HIF-1α) and the prognosis of patients with spinal chordoma.

SUMMARY OF BACKGROUND DATA

Currently, prognostic factors related to the clinical course in the setting of spinal chordoma are poorly understood. Although the close relationship between HIF-1α and tumor angiogenesis, metastasis, and recurrence have been widely reported, it has not been investigated in the context of spinal chordoma.

MATERIALS AND METHODS

In this study, 32 samples of chordoma patients were compared with 14 nucleus pulposus tissues as controls. The specific expression of HIF-1α was detected by immunohistochemistry. Continuous disease-free survival (CDFS) was defined as the interval from tumor resection to confirmation of the first local recurrence or distant metastasis. Overall survival (OS) was defined as the interval from the date of surgery to death related to any cause. The relationship between HIF-1α expression and the clinicopathologic characteristics of patients with chordoma was analyzed using the Pearson χ 2 test. Multivariate Cox analysis was used to evaluate whether HIF-1α expression was associated with the prognosis of patients after controlling for confounders.

RESULTS

HIF-1α was mainly expressed in the cytoplasm or nucleus in all of the chordoma samples, which showed significantly higher than that in the normal nucleus pulposus tissue ( P =0.004). Multivariate Cox regression analyses showed that high HIF-1α expression and location of HIF-1α expression were significantly associated with poor CDFS (hazard ratio (HR)=3.374; P =0.021) and OS (HR=4.511; P =0.012). In addition, we further found that high HIF-1α expression both in the cytoplasm and nucleus indicated a stronger prognostic factor for poor CDFS (HR=3.885; P =0.011) and OS (HR=4.014; P =0.011) in spinal chordoma patients.

CONCLUSION

High HIF-1α expression may become a potential new biological indicator to predict a poor prognosis in patients with spinal chordoma. HIF-1α may also represent a novel therapeutic target for the treatment of spinal chordoma.

Prognostic nomogram in middle-aged and elderly patients with chordoma: A SEER-based study

BACKGROUND

Chordoma is a bone tumor that tends to occur in middle-aged and elderly people. It grows relatively slowly but is aggressive. The prognosis of middle-aged and elderly patients with chordoma is quite different from that of young patients with chordoma.

OBJECTIVES

The purpose of the research was to construct a nomogram to predict the Individualized prognosis of middle-aged and elderly (age greater than or equal to 40 years) patients with chordoma.

METHODS

In this study, we screened 658 patients diagnosed with chordoma from 1983 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. We determined the independently prognostic factors that affect the survival of patients by univariate and multivariate Cox proportional hazards model. Based on the independent prognostic factors, we constructed a nomogram to predict the overall survival (OS) rates of middle-aged and elderly patients with chordoma at 3 and 5 years. The validation of this nomogram was completed by evaluating the calibration curve and the C-index.

RESULTS

We screened a total of 658 patients and divided them into two cohort. Training cohort had 462 samples and validation cohort had 196 samples. The multivariate Cox proportional hazards model of the training group showed an association of age, tumor size, histology, primary site, surgery, and extent of disease with OS rates. Based on these results, we constructed the corresponding nomogram. The calibration curve and C-index showed the satisfactory ability of the nomogram in terms of predictive ability.

CONCLUSION

Nomogram can be an effective prognostic tool to assess the prognosis of middle-aged and elderly patients with chordoma and can help clinicians in medical decision-making and enable patients to receive more accurate and reasonable treatment.

Integrating single-cell and spatial transcriptomics reveals endoplasmic reticulum stress-related CAF subpopulations associated with chordoma progression

BACKGROUND

With cancer-associated fibroblasts (CAFs) as the main cell type, the rich myxoid stromal components in chordoma tissues may likely contribute to its development and progression.

METHODS

Single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, bulk RNA-seq, and multiplexed quantitative immunofluorescence (QIF) were used to dissect the heterogeneity, spatial distribution, and clinical implication of CAFs in chordoma.

RESULTS

We sequenced here 72 097 single cells from 3 primary and 3 recurrent tumor samples, as well as 3 nucleus pulposus samples as controls using scRNA-seq. We identified a unique cluster of CAF in recurrent tumors that highly expressed hypoxic genes and was functionally enriched in endoplasmic reticulum stress (ERS). Pseudotime trajectory and cell communication analyses showed that this ERS-CAF subpopulation originated from normal fibroblasts and widely interacted with tumoral and immune cells. Analyzing the bulk RNA-seq data from 126 patients, we found that the ERS-CAF signature score was associated with the invasion and poor prognosis of chordoma. By integrating the results of scRNA-seq with spatial transcriptomics, we demonstrated the existence of ERS-CAF in chordoma tissues and revealed that this CAF subtype displayed the most proximity to its surrounding tumor cells. In subsequent QIF validation involving 105 additional patients, we confirmed that ERS-CAF was abundant in the chordoma microenvironment and located close to tumor cells. Furthermore, both ERS-CAF density and its distance to tumor cells were correlated with tumor malignant phenotype and adverse patient outcomes.

CONCLUSIONS

These findings depict the CAF landscape for chordoma and may provide insights into the development of novel treatment approaches.

Incidence, Management, and Outcomes of Adult Spinal Chordoma Patients in the United States

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Spinal chordomas are rare primary malignant neoplasms of the primitive notochord. They are slow growing but locally aggressive lesions that have high rates of recurrence and metastasis after treatment. Gold standard treatment remains en-bloc surgical resection with questionable efficacy of adjuvant therapies such as radiation and chemotherapy. Here we provide a comprehensive analysis of prognostic factors, treatment modalities, and survival outcomes in patients with spinal chordoma.

METHODS

Patients with diagnosis codes specific for chordoma of spine, sacrum, and coccyx were queried from the National Cancer Database (NCDB) during the years 2004-2016. Outcomes were investigated using Cox univariate and multivariate regression analyses, and survival curves were generated for comparative visualization.

RESULTS

1,548 individuals were identified with a diagnosis of chordoma, 60.9% of which were at the sacrum or coccyx and 39.1% at the spine. The mean overall survival of patients in our cohort was 8.2 years. Increased age, larger tumor size, and presence of metastases were associated with worsened overall survival. 71.2% of patients received surgical intervention and both partial and radical resection were associated with significantly improved overall survival (P < 0.001). Neither radiotherapy nor chemotherapy administration improved overall survival; however, amongst patients who received radiation, those who received proton-based radiation had significantly improved overall survival compared to traditional radiation.

CONCLUSION

Surgical resection significantly improves overall survival in patients with spinal chordoma. In those patients receiving radiation, those who receive proton-based modalities have improved overall survival. Further studies into proton radiotherapy doses are required.

LOC554202 contributes to chordoma progression by sponging miR-377-3p and up-regulating SMAD3

Chordoma is a rare malignant bone tumor originating from the remnants of the notochord. Here, the role of long noncoding LOC554202 in chordoma progression and its associated mechanism were explored. Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide and colony formation assays. Flow cytometry was conducted to analyze cell apoptosis rate. The migration and invasion of chordoma cells were analyzed by transwell migration and invasion assays and wound healing assays. A xenograft tumor model was established in nude mice to explore the role of LOC554202 in regulating tumor growth in vivo . The interaction between microRNA-377-3p (miR-377-3p) and LOC554202 or sekelsky mothers against d PP (SMAD) family member 3 (SMAD3) was verified by dual-luciferase reporter and RNA immunoprecipitation assays. The glycolytic rate of chordoma cells was analyzed using glucose assay kit, lactic acid kit and ApoSENSOR ADP/ATP ratio assay kit. LOC554202 expression was upregulated in chordoma tissues and cell lines. LOC554202 silencing suppressed the proliferation, migration and invasion and induced the apoptosis of chordoma cells. LOC554202 knockdown restrained xenograft tumor growth in vivo . miR-377-3p was confirmed as a target of LOC554202, and miR-377-3p silencing largely overturned LOC554202 knockdown-mediated anti-tumor effects in chordoma cells. miR-377-3p interacted with the 3' untranslated region (3'UTR) of SMAD3 and miR-377-3p overexpression-mediated antitumor effects in chordoma cells were largely attenuated by SMAD3 overexpression. LOC554202 could positively regulate SMAD3 expression by sponging miR-377-3p in chordoma cells. LOC554202 contributed to the glycolysis of chordoma cells by targeting binding to miR-377-3p/SMAD3 axis. LOC554202 facilitated the proliferation, migration, invasion and glycolysis and inhibited the apoptosis of chordoma cells by mediating miR-377-3p/SMAD3 axis.

Management of Chordoma of the Sacrum and Mobile Spine

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Chordomas account for 1% to 4% of primary tumors of the spine and sacrum.

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En bloc resection is the preferred surgical treatment for the management of chordomas.

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Proton beam radiation is increasingly being used as a postoperative radiation modality for the treatment of chordomas.

XIST sponges miR-320d to promote chordoma progression by regulating ARF6

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XIST was highly expressed in chordoma tissues.

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XIST knockdown inhibited chordoma progression by downregulating ARF6.

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MiR-320d inhibited the malignant behaviors of chordoma cells.

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XIST positively upregulated ARF6 expression via sponging miR-320d in chordoma cells.

Background

Long non-coding RNAs (lncRNAs) have been demonstrated to play important roles in various tumors, including chordoma. The purpose of this study was to investigate the role and mechanism of lncRNA X-inactive specific transcript (XIST) in chordoma.

Methods

RNA levels and protein levels were measured by real-time quantitative polymerase chain reaction (RT‑qPCR) and western blot assay, respectively. Cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2′-deoxyuridine (EdU) assay and colony formation assay. Tanswell assay was used to examine cell migration and invasion. Cellular glycolysis was examined via the measurement of extracellular acidification rate (ECAR) and lactate production. The interaction between microRNA-320d (miR-320d) and XIST or ADP-ribosylation factor 6 (ARF6) was predicted by bioinformatics analysis and verified by a dual-luciferase reporter and RNA-pull down assays. The xenograft tumor model was used to explore the biological function of XIST in vivo.

Results

XIST was overexpressed in chordoma tissues. XIST knockdown suppressed chordoma cell proliferation, migration, invasion, and glycolysis. XIST acted as a sponge of miR-320d. Moreover, miR-320d overexpression inhibited the proliferation, migration, invasion, and glycolysis of chordoma cells. ARF6 was a direct target of miR-320d, and XIST upregulated ARF6 expression via sponging miR-320d. Furthermore, overexpression of ARF6 reversed the inhibitory effects of XIST knockdown on chordoma cell proliferation, migration, invasion, and glycolysis. Importantly, XIST silencing blocked xenograft tumor growth in vivo.

Conclusion

XIST knockdown inhibited chordoma progression via regulating the miR-320d/ARF6 axis, providing a novel insight into chordoma pathogenesis.

Chondrosarcoma and Chordoma of the Skull Base and Spine: Implication of Tumor Location on Patient Survival

BACKGROUND

Chondrosarcoma and chordoma are often grouped together because of their similar anatomic locations, clinical presentations, histopathological and radiological findings, and growth patterns. In the present study, we investigated the clinical and prognostic differences of chondrosarcomas and chordomas of the skull base and spine.

METHODS

We accessed the Surveillance, Epidemiology, and End Results database to search for patients from 2000 to 2018 with chondrosarcomas and chordomas of the skull base and spine for inclusion in the present study.

RESULTS

We included 1346 and 1536 cases of chondrosarcoma and chordoma for analysis, respectively. Chondrosarcomas of the cranial base and spine were seen in younger patients and were associated with a larger tumor size compared with chordomas. Among the tumors of the skull base, chondrosarcomas were more common in women, with a male predominance found for chordomas. We also observed a male predilection for both spinal chondrosarcomas and chordomas. Distinct metastatic patterns were found for chondrosarcomas versus chordomas, and spinal chondrosarcomas showed a greater risk of distant metastases at presentation compared with spinal chordomas. Cranial base chondrosarcomas were associated with superior outcomes compared with chordomas. However, we demonstrated an opposite survival pattern for spinal chondrosarcomas and chordomas.

CONCLUSIONS

Chondrosarcomas and chordomas have divergent clinical manifestations and prognoses depending on the anatomic location.

Coexpression of HHLA2 and PD-L1 on Tumor Cells Independently Predicts the Survival of Spinal Chordoma Patients

Background

Immunotherapy only achieves efficacy in some cancer patients, and less is known about other immune checkpoint molecules in chordoma. Here, we aimed to determine the expression of PD-L1, HHLA2, B7H3, IDO-1 and Galectin-9 in spinal chordoma and evaluated their association with tumor infiltrating lymphocytes (TILs), clinicopathological characteristics and survival of patients.

Methods

Using multiplexed quantitative immunofluorescence (QIF), we simultaneously measured the levels of five different immune checkpoint molecules and major TIL subsets in 92 human spinal chordoma samples.

Results

Tumor HHLA2 and PD-L1 were positive in 80.0% and 86.0% of cases, respectively. However, B7H3, IDO-1 and Galectin-9 positivity on tumor cells were only seen in 21.0% of cases, despite all showing predominantly stromal expression. Coexpression of these QIF markers in the tumor compartment was scarcely detected except for PD-L1 and HHLA2, which was observed in 69.6% of cases. While tumoral HHLA2 and stromal B7H3 expressions were associated with an aggressive tumor phenotype, suppressive immune response (specifically including elevated PD-1⁺ TILs level and decreased CD8⁺ TIL density) and poor prognosis, stromal levels of PD-L1 and Galectin-9 predicted the opposite outcomes. Importantly, HHLA2 and PD-L1 coexpression on tumor cells independently predicted both worse local recurrence-free survival and overall survival.

Conclusion

These data provide a better understanding of the immunosuppressive mechanism in chordoma and may be useful for the development of combination or novel immunotherapy approaches aiming to improve therapeutic efficacy and survival.

Comparison of combined anterior-posterior and posterior-only approaches for lumbosacral chordomas: a systematic review and meta-analysis of surgical and clinical outcomes

Lumbosacral chordoma is a slow-growing but locally aggressive tumor, resistant to adjuvant treatments and endowed with dismal prognosis. Surgery is the mainstay of treatment but the choice of surgical approach (the posterior-only approach or the combined anterior-posterior approach) remains an open question due to the need of both pursuing a surgical radicality and preserving the neurologic function. The aim of the study was to compare the surgical and clinical outcomes of these approaches in the management of lumbosacral chordomas. A systematic review and meta-analysis in agreement with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines of papers comparing the outcomes of the two approaches was performed. Ten papers met the inclusion criteria. The combined anterior-posterior approach was more frequently performed for tumors with an upper level beyond S2 (p = 0.012). The 5-year progression-free survival was significantly higher in posterior-only approach compared with the combined anterior-posterior approach (44.7% vs 27.1%, p = 0.049). Adjuvant radiotherapy was added more frequently after a posterior-only approach (p = 0.036) and the rate of complications was significantly lower after a posterior-only approach (p = 0.040). No significant differences in sex, age, tumor diameter, entity of resection, and overall survival were observed. Posterior-only surgical approach may be a reasonable option for lumbosacral chordoma, being associated with comparable entity of surgical resection, reduced complication rate and increased 5-year progression-free survival rate as compared with combined anterior-posterior approach.

LncRNA NONHSAT114552 Sponges miR-320d to Promote Proliferation and Invasion of Chordoma Through Upregulating NRP1

Chordoma is a relatively rare malignant bone tumor with high local recurrence. To date, the mechanism remains unclear. lncRNAs play a pivotal role in tumorigenesis by acting as competitive endogenous RNAs of microRNAs. However, the biological role of lncRNA is still unclear in chordoma. In this research, our aim is to investigate the roles and regulation mechanisms of lncRNA NONHSAT114552 in chordoma development. The expression level of NONHSAT114552 and miR-320d in chordoma tissues was determined by qRT-PCR. Meantime, the correlation between NONHSAT114552 and clinical prognosis was also studied. Bioinformatics analysis and luciferase reporter assays were used to verify the relationship between NONHSAT114552 and miR-320d, and between miR-320d and Neuropilin 1 (NRP1). In addition, effects of NONHSAT114552 on chordoma cells (U-CH1 and U-CH2) proliferation and invasion and its regulation on miR-320d were also evaluated. Furthermore, the influences of NONHSAT114552/miR-320d/NRP1 axis on chordoma tumorigenesis were investigated in vivo. NONHSAT114552 was overexpressed while miR-320d was down-regulated in chordoma tissue compared to fetal nucleus pulposus. Kaplan-Meier survival analysis showed that NONHSAT114552 overexpression was associated with patients’ poor prognosis. Knockdown of NONHSAT114552 significantly suppressed chordoma cell proliferation and invasion. In vitro studies confirmed that NONHSAT114552 acted as ceRNA to regulate NRP1 by directly sponging miR-320d, thus facilitating chordoma cell proliferation and invasion. In vivo study demonstrated that NONHSAT114552 moderated chordoma growth by sponging miR-320d to regulating NRP1. Our findings indicate that lncRNA NONHSAT114552 exhibits a critical role in the tumorigenesis and development of chordoma and it may become one potential prognostic marker and therapeutic target for this disease. .

A Novel Nomogram for Predicting Cancer-Specific Survival in Patients With Spinal Chordoma: A Population-Based Analysis

Background:

Chordoma is a rare malignant bone tumor, and the survival prediction for patients with chordoma is difficult. The objective of this study was to construct and validate a nomogram for predicting cancer-specific survival (CSS) in patients with spinal chordoma.

Methods:

A total of 316 patients with spinal chordoma were identified from the SEER database between 1998 and 2015. The independent prognostic factors for patients with spinal chordoma were determined by univariate and multivariate Cox analyses. The prognostic nomogram was established for patients with spinal chordoma based on independent prognostic factors. Furthermore, we performed internal and external validations for this nomogram.

Results:

Primary site, disease stage, histological type, surgery, and age were identified as independent prognostic factors for patients with spinal chordoma. A nomogram for predicting CSS in patients with spinal chordoma was constructed based on the above 5 variables. In the training cohort, the area under the curve for predicting 1-, 3-, and 5-year CSS were 0.821, 0.856, and 0.920, respectively. The corresponding area under the curve in the validation cohort were 0.728, 0.804, and 0.839, respectively. The calibration curves of the nomogram showed a high degree of agreement between the predicted and the actual results, and the decision curve analysis further demonstrated the satisfactory clinical utility of the nomogram.

Conclusions:

The prognostic nomogram provides a considerably more accurate prediction of prognosis for patients with spinal chordoma. Clinicians can use it to categorize patients into different risk groups and make personalized treatment methods.

Partial Sacrectomy for Resection of a Sacral Chordoma: 2-Dimensional Operative Video

Sacral chordomas are infrequent tumors that arise from remnants of the notochord. They are most often found in the sacrum and skull-base.1,2 These lesions rarely metastasize and usually have an indolent and oligosymptomatic clinical course. Chordomas show low sensitivity to standard radiation therapy and chemotherapy. Operative resection with wide resection margins offers the best long-term prognosis, including longer survival and local control.1,3 However, achieving a complete resection with oncological margins may be difficult because of the anatomic complexity of the sacrococcygeal region.4 The main complications of sacral resection include infections, wound closure defects, and anorectal and urogenital dysfunction. The rate of these complications is significantly increased when the tumor involves the S2 level or above. We report the case of a 64-yr-old male who presented with progressive sacrococcygeal pain and a feeling of incomplete evacuation. A heterogeneous, osteolytic lesion was found at the sacrococcygeal region. Full body imaging tests were negative for other lesions. A computed tomography (CT) guided biopsy was made. We usually use the midline approach in case we have to include the needle path in the resection. The pathology confirmed a sacrococcygeal, low-grade chordoma. We decided to perform an en bloc resection. A posterior, partial sacrectomy was planned distal to the S4 level.

Outcomes of Surgery for Sacral Chordoma and Impact of Complications: A Report of 50 Consecutive Patients With Long-Term Follow-Up

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To determine predictive factors of overall survival (OS) and local recurrence (LR), report complications, and assess the impact of complications on survival, recurrence, and function in patients undergoing en bloc resection of sacral chordoma.

METHODS

This retrospective case series was obtained from a prospective database (1995-2016). All patients underwent en bloc resection of sacral chordoma. Demographic, perioperative, and complication data were collected. Outcomes included: overall survival(OS), local recurrence(LR), and complications. Survival analysis with multivariable cox regression was performed.

RESULTS

Among 50 patients, median follow-up was 5.3 years (range = 1.3-17.2). The majority (82%) underwent a negative margin resection. Survival: 17 patients died (34%) with a median OS of 10.0 years (range = 1.3-17.2). Multivariable cox regression revealed that a negative margin resection was not significantly associated with improved survival (HR = 3.35, 95%CI 0.87-12.80, P = .078). Recurrence: 20 patients (40%) experienced LR with a median time of 6.2 years (range = 0-16.9). Multivariable cox regression revealed that a negative margin resection was associated with a significant decreased risk of LR (HR = 4.96, 95%CI 1.84-13.34, P = 0.002,). A 62% overall complication rate was seen (42% major), with 26% reoperation rate. Of the reoperations, 54% were delayed (>6 weeks after the index surgery). Multivariable cox regression demonstrated that neither major complication nor reoperation significantly impacted OS (HR = 0.62, 95%CI 0.22-1.79, P = 0.380), LR (HR = 1.28, 95%CI 0.49-3.36, P = 0.611), or functional outcomes (OR = 2.94, 95%CI 0.25-34.8, P = 0.393).

CONCLUSIONS

Negative margin resection was associated with decreased LR. Neither major complication nor reoperation significantly impacted OS, LR, or functional outcome. Though additional studies are needed, it appears that despite the morbidity associated with sacral chordoma resection, the long-term clinical outcomes are favorable.

Knockdown of TMED3 inhibits cell viability and migration and increases apoptosis in human chordoma cells

Chordoma is a rare low‑grade tumor of the axial skeleton. Over previous decades, a range of targeted drugs have been used for treating chordoma, with more specific and effective therapies under investigation. Transmembrane Emp24 protein transport domain containing 3 (TMED3) is a novel gene reported to be a regulator of oncogenesis, cancer development and metastasis; however, its role in chordoma remains unclear. In the present study, the expression of TMED3 was investigated in chordoma cells, and the effect of TMED3 knockdown on chordoma development was examined in vitro and in vivo, followed by exploration of differentially expressed proteins in TMED3‑silenced chordoma cells via an apoptosis antibody array. Reverse transcription‑quantitative PCR and western blot assays were performed to determine the expression levels. It was revealed that TMED3 was highly expressed in chordoma, and that knockdown of TMED3 inhibited cell viability and migration, and enhanced the apoptosis of chordoma cells. Additionally, knockdown of TMED3 inhibited the expression of Bcl‑2, heat shock protein 27, insulin‑like growth factor (IGF)‑I, IGF‑II, IGF binding protein‑2, Livin, Akt, CDK6 and cyclin D1 proteins, whereas MAPK9 was upregulated. Furthermore, a xenograft nude mice model demonstrated that TMED3 expression promoted tumor growth. Collectively, the present findings suggested that knockdown of TMED3 inhibited cell viability and migration, and enhanced apoptosis in chordoma cells, and that TMED3 may be a novel target for chordoma therapy.

Surgical Management of Skull Base and Spine Chordomas

OPINION STATEMENT

Management of chordoma along the cranial-spinal axis is a major challenge for both skull base and spinal surgeons. Although chordoma remains a rare tumor, occurring in approximately 1 per 1 million individuals, its treatment poses several challenges. These tumors are generally poorly responsive to radiation and chemotherapy, leading to surgical resection as the mainstay of treatment. Due to anatomic constraints and unique challenges associated with each primary site of disease, gross total resection is often not feasible and is associated with high rates of morbidity. Additionally, chordoma is associated with high rates of recurrence due to the tumor's aggressive biologic features, and postoperative radiation is increasingly incorporated as a treatment option for these patients. Despite these challenges, modern-day surgical techniques in both skull base and spinal surgery have facilitated improved patient outcomes. For example, endoscopic endonasal techniques have become the mainstay in resection of skull base chordomas, improving the ability to achieve gross total resection, while reducing associated morbidity of open transfacial techniques. Resection of spinal chordomas has been facilitated by emerging techniques in preoperative imaging, intraoperative navigation, spinal reconstruction, and radiotherapy. Taken collectively, the treatment of chordoma affecting the skull base and spinal requires a multidisciplinary team of surgeons, radiation oncologists, and medical oncologists who specialize in the treatment of this challenging disease.

Chordoma-Current Understanding and Modern Treatment Paradigms

Chordoma is a low-grade notochordal tumor of the skull base, mobile spine and sacrum which behaves malignantly and confers a poor prognosis despite indolent growth patterns. These tumors often present late in the disease course, tend to encapsulate adjacent neurovascular anatomy, seed resection cavities, recur locally and respond poorly to radiotherapy and conventional chemotherapy, all of which make chordomas challenging to treat. Extent of surgical resection and adequacy of surgical margins are the most important prognostic factors and thus patients with chordoma should be cared for by a highly experienced, multi-disciplinary surgical team in a quaternary center. Ongoing research into the molecular pathophysiology of chordoma has led to the discovery of several pathways that may serve as potential targets for molecular therapy, including a multitude of receptor tyrosine kinases (e.g., platelet-derived growth factor receptor [PDGFR], epidermal growth factor receptor [EGFR]), downstream cascades (e.g., phosphoinositide 3-kinase [PI3K]/protein kinase B [Akt]/mechanistic target of rapamycin [mTOR]), brachyury—a transcription factor expressed ubiquitously in chordoma but not in other tissues—and the fibroblast growth factor [FGF]/mitogen-activated protein kinase kinase [MEK]/extracellular signal-regulated kinase [ERK] pathway. In this review article, the pathophysiology, diagnosis and modern treatment paradigms of chordoma will be discussed with an emphasis on the ongoing research and advances in the field that may lead to improved outcomes for patients with this challenging disease.

LncRNA-NONHSAT024778 promote the proliferation and invasion of chordoma cell by regulating miR-1290/Robo1 axis

Chordoma is a malignant bone tumor originating from the embryonic remnants of the notochord. lncRNAs act as competing endogenous RNAs (ceRNAs) and play a critical role in tumor pathology. However, the biological role of lncRNA-NONHSAT024778 and the underlying molecular mechanism in chordoma remains unknown. qRT-PCR was used to analyze the expression changes of NONHSAT024778 and miR-1290 in chordoma tissues and cell lines. Bioinformatics analysis and luciferase reporter assay were applied to detect the targeting binding effect between NONHSAT024778 and miR-1290, and between Robo1 and miR-1290. The effect of NONHSAT024778 on chordoma cell proliferation and invasion and its regulation of miR-1290 by acting as a ceRNA were also investigated. An increased NONHSAT024778 expression was correlated with a decreased miR-1290 level in chordoma tissues. NONHSAT024778 knockdown suppressed the proliferation and invasion of chordoma cells. miR-1290 restored expression rescued the carcinogenic function of NONHSAT024778. Bioinformatics analysis showed that NONHSAT024778 acted as ceRNA to regulate Robo1 via sponging miR-1290 in chordoma cells, thereby promoting chordoma cell malignant progression. In vivo results confirmed the anti-tumor effects of NONHSAT024778 knockdown activating miR-1290 to inhibit the oncogene Robo1. NONHSAT024778 is substantially overexpressed, whereas miR-1290 is decreased in chordoma tissue. NONHSAT024778-miR-1290-Robo1 axis plays a critical role in chordoma tumorigenesis and might be a potential predictive biomarker for the diagnosis and therapeutic target among patients with chordoma.

Image-guided percutaneous cryoablation of unresectable sacrococcygeal chordoma: Feasibility and outcome in a selected group of patients with long term follow-up

BACKGROUND

Chordoma is a rare malignant tumor of the axial skeleton. Percutaneous cryoablation (PCA) is a minimally invasive technique that allows freezing of tumors under imaging control. The purpose of our retrospective study was to investigate the outcome of PCA in a selected cohort of patients with sacrococcygeal chordoma, with a minimum of 5 years follow-up.

MATERIALS AND METHODS

Four patients were treated in 10 sessions. The mean follow-up was 57.3 months. We evaluated the feasibility, the procedure-related complications, the impact on pain control and oncological outcomes.

RESULTS

Freezing of 100% of the tumor volume was possible in 60%. Pain control was not reliably evaluable. Local recurrence occurred in 90% of the treated lesions; the mean time to progression was 8.1 months (range 1.5-16). At last follow-up, one patient had died of the disease, one of another cause and one was receiving the best supportive care. The only patient alive without the disease had received additional carbon-ion radiotherapy. The 5-year survival rate after index PCA was 50%.

CONCLUSION

Complete freezing of the tumor was technically challenging, mainly due to the complex local anatomy. Recurrence occurred in 90% of the lesions treated. PCA should be considered with caution in the curative management of sacrococcygeal chordoma.

Translational Windows in Chordoma: A Target Appraisal

Chordomas are rare tumors that are notoriously refractory to chemotherapy and radiotherapy when radical surgical resection is not achieved or upon recurrence after maximally aggressive treatment. The study of chordomas has been complicated by small patient cohorts and few available model systems due to the rarity of these tumors. Emerging next-generation sequencing technologies have broadened understanding of this disease by implicating novel pathways for possible targeted therapy. Mutations in cell-cycle regulation and chromatin remodeling genes have been identified in chordomas, but their significance remains unknown. Investigation of the immune microenvironment of these tumors suggests that checkpoint protein expression may influence prognosis, and adjuvant immunotherapy may improve patient outcome. Finally, growing evidence supports aberrant growth factor signaling as potential pathogenic mechanisms in chordoma. In this review, we characterize the impact on treatment opportunities offered by the genomic and immunologic landscape of this tumor.

The Relationship Between Tumor-Stroma Ratio, the Immune Microenvironment, and Survival in Patients With Spinal Chordoma

BACKGROUND

Currently, little is known about the clinical relevance of tumor-stroma ratio (TSR) in chordoma and data discussing the relationship between TSR and immune status of chordoma are lacking.

OBJECTIVE

To characterize TSR distribution in spinal chordoma, and investigated its correlation with clinicopathologic or immunological features of patients and outcome.

METHODS

TSR was assessed visually on hematoxylin and eosin-stained sections from 54 tumor specimens by 2 independent pathologists. Multiplex immunofluorescence was used to quantify the expression levels of microvessel density, Ki-67, Brachyury, and tumor as well as stromal PD-L1. Tumor immunity status including the Immunoscore and densities of tumor-infiltrating lymphocytes (TILs) subtypes were obtained from our published data and reanalyzed.

RESULTS

Bland-Altman plot showed no difference between mean TSR derived from the two observers. TSR was positively associated with stromal PD-L1 expression, the Immunoscore and CD3+ as well as CD4+ TILs density, but negatively correlated with tumor microvessel density, Ki-67 index, surrounding muscle invasion by tumor and number of Foxp3+ and PD-1+ TILs. Low TSR independently predicted poor local recurrence-free survival and overall survival. Moreover, patients with low TSR and low Immunoscore chordoma phenotype were associated with the worst survival. More importantly, combined TSR and Immunoscore accurately reflected prognosis and enhanced the ability of TSR or Immunoscore alone for outcome prediction.

CONCLUSION

These data reveal the significant impact of TSR on tumor progression and immunological response of patients. Subsequent use of agents targeting the stroma compartment may be an effective strategy to treat chordoma especially in combination with immune-based drugs.

Natural History of a Patient with Sacral Chordoma: Case Report and Literature Review

BACKGROUND

Chordomas are rare, slow-growing, locally aggressive, malignant tumors of the spine. Chordomas are conventionally treated with surgical resection with or without radiation. There is an absence of literature documenting the natural history of a primary sacral chordoma.

CASE DESCRIPTION

A 65-year-old man presented with rectal pain, constipation, urinary and fecal incontinence, S1 radiculopathy, and a palpable rectal mass. A needle biopsy confirmed the pathologic diagnosis of sacral chordoma. The patient declined to have surgery because of the surgical risks involved. He was managed conservatively with supportive care only. The patient was routinely followed in clinic and had a subjective and objective excellent quality of life with adequate pain management. Meanwhile, his neurologic status did not deteriorate. During follow-up, some posterolateral aspects of the chordoma regressed. However, the bulk of the lesion continued to slowly progress. The patient survived for 7.5 years. He eventually succumbed to urosepsis and new-onset peritoneal metastasis.

CONCLUSIONS

To our knowledge, the patient is the only documented case in the literature of an untreated biopsy-proven sacral chordoma. The patient's tumor was intended for resection, and therefore comparable with data from treated chordomas. The patient's survival is similar to the median survival in treated chordomas. The patient's survival was despite negative prognosticators, such as advanced age of the patient and high sacral location above S2.

Risk Factors for Wound-Related Complications After Surgery for Primary and Metastatic Spine Tumors: A Systematic Review and Meta-Analysis

OBJECTIVE

We systematically reviewed the literature to compare risk factors for postoperative complications at the surgical wound site in primary and metastatic tumor operations.

METHODS

We screened English-language publications on the outcomes of primary and metastatic spinal tumor operations. Pooled analyses and meta-analyses with random-effects modeling were performed comparing patients with and without wound complications, which were defined as surgical site infection or sterile wound dehiscence.

RESULTS

Our search identified 5471 unique citations, from which we included 23 studies describing 5104 patients. A total of 1936 patients underwent surgery for primary tumors, with a wound complication rate of 8.1%. Subgroup analysis of benign and malignant primary tumors yielded significantly different wound complication rates of 7.8% and 26.9%, respectively. The metastatic tumor cohort included 168 patients and a complication rate of 6.6%. In a pooled analysis of primary tumors, higher wound complication rates were associated with sacral operations and the use of instrumentation. In the metastatic tumor cohort, higher complication rates were associated with female sex, smoking history, preoperative chemotherapy, preoperative radiotherapy, corticosteroid use, and previous spine surgery. Instrumentation remained a statistically significant risk factor for primary tumors with the addition of random-effects meta-analysis.

CONCLUSIONS

Risk factors for wound complications after primary tumor operations were related to tumor histology and the spinal location of the operation. Risk factors for metastatic tumors may be related to several systemic preoperative treatments and baseline comorbidities. Random-effects meta-analysis showed the limited generalizability of these findings because of the small heterogenous primary literature.

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.

Predictive role of Apparent Diffusion Coefficient (ADC) from Diffusion Weighted MRI in patients with sacral chordoma treated with carbon ion radiotherapy (CIRT) alone

PURPOSE

To evaluate if baseline ADC from DWI sequences could predict response to treatment in patients with sacral chordoma not suitable for surgery treated with carbon ion radiotherapy (CIRT) alone compared with volume changes.

METHODS

Fifty-nine patients with sacral chordoma not suitable for surgery underwent one cycle of CIRT alone and a minimum of 12-months follow-up. All patients underwent MRI before treatment (baseline), every three months in the first two years after treatment, and every six months afterwards. For each MRI, lesion volume was obtained and median, kurtosis, and skewness ADC were analyzed within the whole lesion volume. Volume changes between baseline and the last available follow-up were used to divide patients with partial response, progression of disease and stable disease (PR, PD, and SD).

RESULTS

Ten patients were excluded since DWI sequences from baseline MRI were not available. ADC maps obtained from baseline DWI examinations of 50 lesions in the remaining 49 patients were considered. Seven lesions were categorized as PD, 30 PR, and 13 SD. PD showed significantly higher median ADC values at baseline (p = 0.003) compared with both PR and SD (1665vs1253vs1263 *10^-6 mm²/s), and more negative skewness values (-0.26vs0.26vs0.08), although not significantly different (p = 0.16).

CONCLUSIONS

Preliminary results suggest that baseline ADC could predict response to treatment with CIRT, particularly to detect potential non-responder patients.

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.

Upregulation Of miR-149-3p Suppresses Spinal Chordoma Malignancy By Targeting Smad3

Purpose

Dysregulation of miRNAs plays an important role in the malignancy of different tumors including chordoma. Expression of miR-149-3p was earlier reported to be downregulated in chordoma tissue. However, its biological role remains to be unrevealed in chordoma, especially in spinal chordoma.

Methods

Expression of miR-149-3p and Smad3 was detected by RT-qPCR and Western blot. Chordoma malignancy was evaluated by cell proliferation, migration, invasion, and apoptosis using MTT assay, transwell assay, flow cytometry analyzing apoptosis rate, and Western blot-determined expression of Bcl-2, Bax, and cleaved caspase 3, respectively. The target binding between miR-149-3p and Smad3 was predicted by TargetScan Human website and confirmed by luciferase reporter assay and RNA immunoprecipitation. Xenograft tumors were generated, and expression of miR-149-3p and Smad3 was investigated in vivo.

Results

miR-149-3p was downregulated in spinal chordoma tissues and cells, and its overexpression promoted chordoma cell apoptosis and inhibited proliferation, migration, and invasion in U-CH1 and MUG-Chor1 cells. Unexpectedly, Smad3 was a downstream target of miR-149-3p and negatively correlated with miR-149-3p expression in chordoma tissues. Besides, Smad3 was upregulated in chordoma tissues and its silencing had a similar effect as miR-149-3p overexpression in U-CH1 and MUG-Chor1 cells. Moreover, Smad3 upregulation could partially reverse the tumor-suppressive effect of miR-149-3p in chordoma cells. In vivo, the tumorigenesis of U-CH1 and MUG-Chor1 cells was impaired by upregulated miR-149-3p through decreasing Smad3 expression.

Conclusion

miR-149-3p could serve as a tumor suppressor in spinal chordoma through targeting and downregulating Smad3.

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.

Application of nomograms to predict overall and cancer-specific survival in patients with chordoma

Background

The survival prediction of patients with chordoma is difficult to make due to the rarity of this oncologic disease. Our objective was to apply a nomogram to predict survival outcomes in individuals with chordoma of the skull base, vertebral column, and pelvis.

Methods

A total of 558 patients with chordoma between 1973 and 2014 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Independent prognostic factors in patients with chordoma were identified via univariate and multivariate Cox analysis. Then these prognostic factors were incorporated into a nomogram to predict 3- and 5-year overall survival and cancer-specific survival rates. Internal and external data were used to validate the nomograms. Concordance indices (C-indices) were used to estimate the accuracy of this nomogram system.

Results

A total of 558 patients were randomly assigned into a training cohort (n = 372) and a validation cohort (n = 186). Age, surgical stage, tumor size, histology, primary site, and use of surgery were identified as independent prognostic factors via univariate and multivariate Cox analysis (all p < 0.05) and further included to establish the nomogram. The C-indices for overall survival and cancer-specific survival prediction of the training cohort were 0.775 (95% confidence interval, 0.770-0.779) and 0.756 (95% confidence interval, 0.749 -0.762). The calibration plots both showed an excellent consistency between actual survival and nomogram prediction.

Conclusion

Nomograms were constructed to predict overall survival and cancer-specific survival for patients with chordoma of the skull base, vertebral column, and pelvis. The nomogram could help surgeons to identify high risk of mortality and evaluate prognosis in patients with chordoma.

Conditional survival and changing risk profile in patients with chordoma: a population-based longitudinal cohort study

Objective

To evaluate the conditional survival of patients with chordoma to potentially help physician planning of optimal cancer surveillance and guide better clinical decisions.

Methods

In total, 1942 patients with chordoma were identified and extracted from Surveillance, Epidemiology, and End Results (SEER) databases (1973–2015). The cumulative survival estimates were used to calculate the conditional survival rate, and the Greenwood formula was used to estimate the 95% CI. In addition, multivariable Cox regression analyses were used to calculate hazard ratios, according to the duration of survival.

Results

The conditional 5-year disease-specific survival in patients with regional or localized chordoma was relatively stable over time, whereas in patients with distant chordoma, there was a gradual improvement. The conditional 5-year disease-specific survival (DSS) of patients older than 60 years old and patients with a tumor size between 5 and 10 cm improved. Interestingly, for patients with a tumor larger than 10 cm, the conditional 5-year DSS decreased over time. After surviving 5 years, the hazard ratio (HR) of patients older than 60 years old decreased from 1.33 to 1.24, that of patients with a tumor size between 5 and 10 cm decreased from 1.61 to 1.52 and that of patients with distant metastasis decreased from 3.30 to 1.09. However, after surviving 5 years, the HR of patients with a tumor size larger than 10 cm increased from 2.33 to 3.77, that of patients who underwent surgical resection increased from 0.37 to 0.58 and that of patients who received radiation therapy increased from 0.81 to 1.04.

Conclusion

Age at diagnosis, tumor size and disease stage can influence conditional survival for patients with chordoma. The HR of different factors will change over the survival time. Therefore, understanding the changing risk profile and conditional 5-year DSS of chordoma is critical for accurate clinical treatment guidance.

miR-1290 inhibits chordoma cell proliferation and invasion by targeting Robo1

BACKGROUND

Chordoma is a low-grade aggressive bone tumor with a high local recurrence. MicroRNAs (miRNAs) have been reported to play crucial roles in the development of chordoma. Our previous study has shown miR-1290 is associated with muscle invasion and the prognosis of chordoma. However, the underlying mechanism of miR-1290 in chordoma remains unclear. In this study, we aimed to explore the function of miR-1290 in the biological behaviors of chordoma.

METHODS

Sixteen sacral chordoma samples and 10 fetal nucleus pulposus specimens were collected for the detection of miR-1290 and Robo1 at the First Affiliated Hospital of Soochow University. Bioinformatic analysis and a luciferase reporter assay was used to verify the interaction between miR-1290 and the target gene robo1 in chordoma. Effects of miR-1290 expression on chordoma cell proliferation and invasion were explored by clone formation and Transwell assay in vitro. The underlying mechanisms of miR-1290 and Robo1 in chordoma cell proliferation and invasion were also explored in the U-CH1 cell line.

RESULTS

In vitro functional analysis, including clone formation, and Transwell assays indicated overexpression of miR-1290 significantly suppressed chordoma cell proliferation and invasion. Bioinformatic analysis revealed Robo1 as a potential target of miR-1290, and luciferase reporter assays demonstrated the association between miR-1290 and the Robo1 gene in U-CH1 cells. Robo1 was further confirmed to be up-regulated in chordoma tissues by immunohistochemistry (IHC), which is negatively correlated with miR-1290 expression in chordoma tissue. Additionally, we found down-regulation of miR-1290 could induce the expression of Robo1 in chordoma cells, while the elevation of miR-1290 expression could inhibit Robo1 expression in chordoma cells.

CONCLUSIONS

miR-1290 inhibits chordoma cell proliferation and invasion by negatively regulating the Robo1 gene.

Predictive Value of Preoperative Magnetic Resonance Imaging Findings for Survival and Local Recurrence in Patients Undergoing En Bloc Resection of Sacral Chordomas

BACKGROUND

Few studies have assessed the prognostic importance of preoperative magnetic resonance imaging (MRI) scan findings in patients undergoing en bloc resection of sacral chordomas.

OBJECTIVE

To (1) report in-depth imaging characteristics of sacral chordomas, (2) describe the patterns of local and distant recurrence, and (3) determine imaging predictors of overall survival (OS) and local recurrence (LR).

METHODS

This retrospective case series was obtained from a prospectively maintained spine database from 1995 to 2016. All patients underwent en bloc resection of sacral chordomas. Detailed demographic, outcome, and MRI data were collected. A survival analysis was completed with multivariable cox regression to assess the impact of MRI findings on OS and LR.

RESULTS

A total of 41 patients underwent en bloc resection of sacral chordoma with preoperative MRI scans. Tumor characteristics included lobulated: (93%) and soft tissue tail (54%). The following areas had tumor invasion lobulated: sacroiliac (SI) joint (15%), ilium (5%), piriformis (61%), gluteus (46%), subcutaneous fat (32%), and lumbosacral venous plexus (22%). After multivariable analysis, only subcutaneous fat extension was an independent predictor of decreased OS (hazard ratio 5.30, 95% confidence interval 1.47-19.19, P = .011). Though not significant after multivariable analysis, the following factors were significant predictors of LR after univariate logrank testing: above the L5/S1 disc space (P = .004), SI joint invasion (P = .036), and piriformis extension (P = .022).

CONCLUSION

The presence of subcutaneous fat extension was an independent predictor of decreased OS. Other MRI findings with potential for future evaluation include size, presence of soft tissue tail, extension above L5/S1, and SI joint and piriformis invasion.

[A giant sacral chordoma resection and reconstruction with a gluteal perforator flap, a case report and literature review]

BACKGROUND

Sacral chordomas are rare primary bone tumors and represent more than half of all primary malignant sacral tumors. Surgical resection is the only treatment with close to 50% of remission at 10 years, with or without radiotherapy. This tissue removal can be very extensive and morbid, particularly for evolved tumors. The reconstruction mostly uses myocutaneous flaps, notably the gluteus maximus flap and the latissimus dorsi flap, increasing morbidity of the surgical procedure. To avoid a muscular sacrifice and reduce the post-surgical morbidity, we describe the case of a patient who underwent a giant sacral chordoma resection and a reconstruction with a superior gluteal artery perforator flap.

CASE REPORT

A 57-y.o. patient with a voluminous sacral chordoma had undergone a partial sacrectomy and abdomino-perineal resection. Firstly, a laparoscopy was realized to create a colostomy, to dissect an omental flap and to prepare the monobloc resection. In a prone position, the resection of the tumor was achieved and a de-epithelialized superior gluteal artery perforator flap was performed to fill the space and to support pelvic organs.

CONCLUSION

For resections of sacral chordomas, coelioscopy has considerably reduced the surgical morbidity. However, the majority of reconstructions use myocutaneous flaps, specifically gluteus maximus and latissimus dorsi, which their postural function is considerable. Muscular sacrifice can lead to functional impotence with difficulty walking and standing up and run contrary to the diminution morbidity initiated by oncologic surgeons.

Factors Associated With Spinopelvic Fixation Mechanical Failure After Total Sacrectomy

STUDY DESIGN

We retrospectively analyzed factors associated with spinopelvic mechanical failure after total sacrectomy.

OBJECTIVE

To find the rate and type of mechanical fixation failure after total sacrectomy and to identify the associated risk factors.

SUMMARY OF BACKGROUND DATA

Although rigid fixation has been achieved, mechanical failure is sometimes encountered in reconstruction after total sacrectomy. The incidence and factors associated with spinopelvic fixation mechanical failure after total sacrectomy are still not clear.

METHODS

The study comprised 63 patients who underwent spinopelvic reconstruction after total sacrectomy. The potential risk factors for fixation mechanical failure after total sacrectomy were evaluated, which included age, sex, body mass index, type of tumor (benign or malignant), and adjuvant treatment received (e.g., chemotherapy, radiation therapy). The surgery-related factors included the classification of tumor resection (en bloc or piecemeal resection) and the type of iliosacral resection. Adoption of anterior spinal column fixation (ASCF), posterior pelvic ring fixation (PPRF), four-rod technique (FRT) of spinopelvic fixation (SPF), and structural or morselized bone grafting after total sacrectomy in patients were considered reconstruction-related factors. Cox regression models were used to analyze associations between postoperative fixation failure and risk factors for all models.

RESULTS

Postoperative fixation mechanical failure occurred in 25% of patients (16/63) who underwent total sacrectomy. Univariate analysis showed that the factors associated with spinopelvic fixation mechanical failure after total sacrectomy were the non-adoption of FRT of SPF and ASCF, the adoption of Type II sacroiliac resection, and female sex, whereas multivariate analysis demonstrated similar results, except for the adoption of Type II sacroilliac resection.

CONCLUSION

FRT connection of SPF and ASCF should be adopted in reconstruction after total sacrectomy, especially in female patients.

LEVEL OF EVIDENCE

3.

Sacral chordoma: clinical experience of a series of 11 patients over 18 years

Sacral chordoma are rare low-to-intermediate grade malignant tumours that occur most commonly within the sacrum. Sacrectomy with wide resection margins seems to offer the best long-term prognosis.  This study aims to review the management of sacral chordomas including the duration of symptoms, features, treatment, complications and local recurrence rate following surgery at a tertiary centre. We retrospectively reviewed 11 patients treated at our institution between years 1999 and 2015. Patient data included age, sex, history, radiographs, surgical details, onset of recurrence, subsequent treatment, disease-free survival and overall survival were analyzed. Nine patients underwent surgical management with 1 through a sacral approach and eight patients through a combined abdominosacral approach. Despite wide resection in our series, sacral chordoma poses a major problem with approximately 60% of patients having local recurrence in their follow-up.

Role of the Apparent Diffusion Coefficient as a Predictor of Tumor Progression in Patients with Chordoma

BACKGROUND AND PURPOSE

Diffusion-weighted imaging may aid in distinguishing aggressive chordoma from nonaggressive chordoma. This study explores the prognostic role of the apparent diffusion coefficient in chordomas.

MATERIALS AND METHODS

Sixteen patients with residual or recurrent chordoma were divided postoperatively into those with an aggressive tumor, defined as a growing tumor having a doubling time of <1 year, and those with a nonaggressive tumor on follow-up MR images. The ability of the ADC to predict an aggressive tumor phenotype was investigated by receiver operating characteristic analysis. The prognostic role of ADC was assessed using a Kaplan-Meier curve with a log-rank test.

RESULTS

Seven patients died during a median follow-up of 48 months (range, 4-126 months). Five of these 7 patients were in the aggressive tumor group, and 2 were in the nonaggressive tumor group. The mean ADC was significantly lower in the aggressive tumor group than in the nonaggressive tumor group (P = .002). Receiver operating characteristic analysis showed that a cutoff ADC value of 1.494 × 10^-3 × mm²/s could be used to diagnose aggressive tumors with an area under the curve of 0.983 (95% CI, 0.911-1.000), a sensitivity of 1.000 (95% CI, 0.541-1.000), and a specificity of 0.900 (95% CI, 0.555-0.998). Furthermore, a cutoff ADC of ≤1.494 × 10^-3 × mm²/s was associated with a significantly worse prognosis (P = .006).

CONCLUSIONS

Lower ADC values could predict tumor progression in postoperative chordomas.

Robot-assisted sacral tumor resection: a preliminary study

Background

Few studies have been done on robot-assisted sacral surgery. This study aims to evaluate the outcomes of seven patients with benign sacral or presacral tumors treated with a robotic surgical system at a single center.

Methods

All patients with benign sacral or presacral tumors who underwent transperitoneal resection (between June 2015 and June 2016) using the da Vinci Si HD robotic surgical system (Intuitive Surgical Inc.) were included in this retrospective study.

Results

Seven patients with a mean age of 43.8 years (range: 22- 62 years) were included in this study. The operation time ranged from 60 to 335 min. Five out of these seven patients with presacral tumor underwent complete tumor resection by the da Vinci robotic surgical system, with a median blood loss of 52 ml. The other patients underwent excision of the presacral tumor by the da Vinci robotic surgical system, followed by a posterior approach, with a median blood loss of 675 ml. The histological diagnosis was schwannoma of the sacral nerve in five cases (71.5%). The other two cases were chordoma and solitary fibroma of the sacrum, respectively. No perioperative or postoperative complications were encountered. The average hospitalization stay was 5.7 days. No recurrences were found at follow-up 24 to 31 months later.

Conclusion

Robot-assisted minimally invasive sacral surgery can provide precise dissection of the tissue under a perfect view. It is a technically feasible procedure that is associated with minimal blood loss, fewer injuries and short hospitalization. It is particularly suitable for presacral benign tumors.

Prognostic Factors in Patients With Spinal Chordoma: An Integrative Analysis of 682 Patients

BACKGROUND

The low incidence of spinal chordoma precludes a prospective study of prognostic factors with a large patient cohort.

OBJECTIVE

To perform a comprehensive integrative analysis on the prognostic factors, treatment, and outcomes of patients with spinal chordoma using data from 2 institutions and the literature.

METHODS

Appropriate studies were identified per search criteria. The local database was retrospectively searched to include a similar patient cohort.

RESULTS

Overall, 108 studies from the literature and 30 patients from our local institution were identified, resulting in a total of 682 patients. The median age was 57 years old and 35.2% were female. The median follow-up was 46 months (range: 1-408). The median progression-free survival (PFS) and overall survival (OS) were 72 months and 115 months, respectively. Significant prognostic factors for PFS on multivariate analysis included age (pediatric vs adult, hazard ratio [HR]: 2.00-14.36), tumor location (mobile spine vs sacral spine, HR: 0.31-0.87), pathology (differentiated vs classic, HR: 2.48-10.90),and chemotherapy (HR:1.11-3.85). Significant prognostic factors for OS on multivariate analysis included age (geriatric vs adult, HR: 1.52-3.45 and pediatric vs adult, HR: 1.73-9.36), bladder or bowel dysfunction (HR: 1.27-5.43), pathology (dedifferentiated vs classic, HR: 2.38-11.09), recurrence or progression (HR: 1.72-4.48), and metastases (HR: 1.11-2.47).

CONCLUSION

In patients with spinal chordoma, young age, location in sacral spine, dedifferentiated pathology, and chemotherapy were negative predictors of PFS, while young and old age, bladder or bowel dysfunction at presentation, dedifferentiated pathology, recurrence or progression, and metastases portended a worse OS.