Single-cell sequencing reveals VEGFR as a potential target for CAR-T cell therapy in chordoma

BACKGROUND

Chordomas are rare osseous neoplasms with a dismal prognosis when they recur. Here we identified cell surface proteins that could potentially serve as novel immunotherapeutic targets in patients with chordoma.

METHODS

Fourteen chordoma samples from patients attending Xuanwu Hospital Capital Medical University were subjected to single-cell RNA sequencing. Target molecules were identified on chordoma cells and cancer metastasis-related signalling pathways characterised. VEGFR-targeting CAR-T cells and VEGFR CAR-T cells with an additional TGF-β scFv were synthesised and their in vitro antitumor activities were evaluated, including in a primary chordoma organoid model.

RESULTS

Single-cell transcriptome sequencing identified the chordoma-specific antigen VEGFR and TGF-β as therapeutic targets. VRGFR CAR-T cells and VEGFR/TGF-β scFv CAR-T cells recognised antigen-positive cells and exhibited significant antitumor effects through CAR-T cell activation and cytokine secretion. Furthermore, VEGFR/TGF-β scFv CAR-T cells showed enhanced and sustained cytotoxicity of chordoma cell lines in vitro compared with VRGFR CAR-T cells.

CONCLUSIONS

This study provides a comprehensive single-cell landscape of human chordoma and highlights its heterogeneity and the role played by TGF-β in chordoma progression. Our findings substantiate the potential of VEGFR as a target for CAR-T cell therapies in chordoma which, together with modulated TGF-β signalling, may augment the efficacy of CAR-T cells.

The role of systemic therapy in advanced skull base chordomas: overview of the current state and the MD Anderson protocol

The role of systemic therapy in primary or advanced and metastatic chordoma has been traditionally limited because of the inherent resistance to cytotoxic therapies and lack of specific or effective therapeutic targets. Despite resection and adjuvant radiation therapy, local recurrence rates in clival chordoma remain high and the risk of systemic metastases is not trivial, leading to significant morbidity and mortality. Recently, molecular targeted therapies (MTTs) and immune checkpoint inhibitors (ICIs) have emerged as promising therapeutic avenues in chordoma. In recent years, preclinical studies have identified potential targets based on intrinsic genetic dependencies, epigenetic modulators, or newly identified tumor-associated cell populations driving treatment resistance and recurrence. Nonetheless, the role of systemic therapies in the neoadjuvant or adjuvant setting for primary, locally progressive, and distant metastatic chordomas is still being investigated. Herein, an overview of current and emerging systemic treatment strategies in advanced clival chordoma is provided. Furthermore, several molecular biomarkers have been recently uncovered as potential predictors of the response to specific molecular therapeutics. The authors describe the recently discovered role of 1p36 and 9p21 deletions as biomarkers capable of guiding drug selection. Then they discuss completed and ongoing clinical trials of MTTs, including several tyrosine kinase inhibitors used as monotherapy or in combination, such as imatinib, sorafenib, dasatinib, and lapatinib, among others, as well as mammalian target of rapamycin inhibitors such as everolimus and rapamycin. They present their experience and other recent studies demonstrating vast benefits in advanced chordoma from ICIs. Additionally, they provide a brief overview of novel systemic strategies such as adoptive cell transfer (CAR-T and NK cells), oncolytic viruses, epigenetic targeting (KDM6, HDAC, and EZH2 inhibitors), and several promising preclinical studies with high translational potential. Finally, the authors present their institutional multidisciplinary protocol for the incorporation of systemic therapy for both newly diagnosed and recurrent chordomas based on molecular studies including upfront enrollment in MTT trials in patients with epidermal growth factor receptor upregulation or INI-1 deficiency or enrollment in ICI clinical trials for patients with high tumor mutational burden or high PD-L1 expression on tumor cells or in the tumor microenvironment.

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.

Unraveling molecular advancements in chordoma tumorigenesis and treatment response: a review of scientific discoveries and clinical implications

Chordomas are tumors thought to originate from notochordal remnants that occur in midline structures from the cloves of the skull base to the sacrum. In adults, the most common location is the sacrum, followed by the clivus and then mobile spine, while in children a clival origin is most common. Most chordomas are slow growing. Clinical presentation of chordomas tend to occur late, with local invasion and large size often complicating surgical intervention. Radiation therapy with protons has been proven to be an effective adjuvant therapy. Unfortunately, few adjuvant systemic treatments have demonstrated significant effectiveness, and chordomas tend to recur despite intensive multimodal care. However, insight into the molecular underpinnings of chordomas may guide novel therapeutic approaches including selection for immune and molecular therapies, individualized prognostication of outcomes, and real-time noninvasive assessment of disease burden and evolution. At the genomic level, elevated levels of brachyury stemming from duplications and mutations resulting in altered transcriptional regulation may introduce druggable targets for new surgical adjuncts. Transcriptome and epigenome profiling have revealed promoter- and enhancer-dependent mechanisms of protein regulation, which may influence therapeutic response and long-term disease history. Continued scientific and clinical advancements may offer further opportunities for treatment of chordomas. Single-cell transcriptome profiling has further provided insight into the heterogeneous molecular pathways contributing to chordoma propagation. New technologies such as spatial transcriptomics and emerging biochemical analytes such as cell-free DNA have further augmented the surgeon-clinician's armamentarium by facilitating detailed characterization of intra- and intertumoral biology while also demonstrating promise for point-of-care tumor quantitation and assessment. Recent and ongoing clinical trials highlight accelerating interest to translate laboratory breakthroughs in chordoma biology and immunology into clinical care. In this review, the authors dissect the landmark studies exploring the molecular pathogenesis of chordoma. Incorporating this into an outline of ongoing clinical trials and discussion of emerging technologies, the authors aimed to summarize recent advancements in understanding chordoma pathogenesis and how neurosurgical care of chordomas may be augmented by improvements in adjunctive treatments.

Incidence and centralization of chordoma in the Netherlands: A nationwide study between 1991 and 2020

INTRODUCTION

Chordomas are rare malignant bone tumors arising in the axial skeleton, with an incidence of 0.3-0.88 per million inhabitants. We studied the annual incidence rate and centralization of treatment for chordoma in the Netherlands.

METHODS

We retrieved pathology excerpts from the PALGA nationwide Dutch Pathology Registry between 1991 and 2019 for patients with a chordoma to calculate incidence rates. From pathology reports we extracted patient age at diagnosis, sex, year of diagnosis, localization of primary tumor, histologic chordoma subtype (conventional including chondroid, poorly differentiated or dedifferentiated), center of diagnosis (bone tumor referral center (BTC) or other hospital), and partial identification of the BTCs.

RESULTS

A total of 420 individual chordoma patients were identified in the given time period. The incidence of chordoma increased from 0.593 per million inhabitants between 1991-1995 to 1.111 from 2015-2019 (P = 0.001). Median age at diagnosis was 63 years (range 1-95), 252 patients (60%) were male. The proportion of samples analyzed in a BTC either primarily or secondary, as a consultation, revision or referral, increased significantly from 29.3% to 84.4% (P < 0.001). Most primary and secondary samples were analyzed at the Leiden University Medical Center (LUMC, 54.4% and 57% respectively).

CONCLUSIONS

This study shows an increase in the standardized incidence of pathology proven chordoma in the Netherlands. We observed an increase in samples being analysed in the specialized BTCs as well, which is in line with current guidelines and will hopefully lead to more accurate diagnoses and optimal treatment plans for chordoma patients in specialized treatment centers.

Multimodal profiling of chordoma immunity reveals distinct immune contextures

BACKGROUND

Chordomas are rare cancers from the axial skeleton which present a challenging clinical management with limited treatment options due to their anatomical location. In recent years, a few clinical trials demonstrated that chordomas can respond to immunotherapy. However, an in-depth portrayal of chordoma immunity and its association with clinical parameters is still lacking.

METHODS

We present a comprehensive characterization of immunological features of 76 chordomas through application of a multimodal approach. Transcriptomic profiling of 20 chordomas was performed to inform on the activity of immune-related genes through the immunologic constant of rejection (ICR) signature. Multidimensional immunophenotyping through imaging mass cytometry was applied to provide insights in the different immune contextures of 32 chordomas. T cell infiltration was further evaluated in all 76 patients by means of multispectral immunofluorescence and then associated with clinical parameters through univariate and multivariate Cox proportional hazard models as well as Kaplan-Meier estimates. Moreover, distinct expression patterns of human leukocyte antigen (HLA) class I were assessed by immunohistochemical staining in all 76 patients. Finally, clonal enrichment of the T cell receptor (TCR) was sought through profiling of the variable region of TCRB locus of 24 patients.

RESULTS

Chordomas generally presented an immune "hot" microenvironment in comparison to other sarcomas, as indicated by the ICR transcriptional signature. We identified two distinct groups of chordomas based on T cell infiltration which were independent from clinical parameters. The highly infiltrated group was further characterized by high dendritic cell infiltration and the presence of multicellular immune aggregates in tumors, whereas low T cell infiltration was associated with lower overall cell densities of immune and stromal cells. Interestingly, patients with higher T cell infiltration displayed a more pronounced clonal enrichment of the TCR repertoire compared with those with low T cell counts. Furthermore, we observed that the majority of chordomas maintained HLA class I expression.

CONCLUSION

Our findings shed light on the natural immunity against chordomas through the identification of distinct immune contextures. Understanding their immune landscape could guide the development and application of immunotherapies in a tailored manner, ultimately leading to an improved clinical outcome for patients with chordoma.

Organ-Preserving Treatment Strategy for Extra-Axial Chordoma Metastatic to the Larynx Causing Airway Compromise

Chordomas are rare, malignant bone tumors that arise from embryological remnants of the notochord, typically affecting the skull base, mobile spine, and sacrum with uncommon metastasis to the larynx. Patients with metastasis to the larynx may present with slowly progressive dysphonia and dyspnea. Here, we report an organ-preservation treatment strategy for a patient with widely metastatic extra-axial chordoma presenting with airway compromise who was found to have a new metastasis to the cricoid cartilage.

The role of tumor immune microenvironment in chordoma: promising immunotherapy strategies

Chordoma is a rare malignant bone tumor with limited therapeutic options, which is resistant to conventional chemotherapy and radiotherapy, and targeted therapy is also shown with little efficacy. The long-standing delay in researching its mechanisms of occurrence and development has resulted in the dilemma of no effective treatment targets and no available drugs in clinical practice. In recent years, the role of the tumor immune microenvironment in driving tumor growth has become a hot and challenging topic in the field of cancer research. Immunotherapy has shown promising results in the treatment of various tumors. However, the study of the immune microenvironment of chordoma is still in its infancy. In this review, we aim to present a comprehensive reveal of previous exploration on the chordoma immune microenvironment and propose promising immunotherapy strategies for chordoma based on these characteristics.

Clinical management of pediatric chordomas: a comprehensive review

Chordomas are malignant tumors derived from remnants of the notochord. These are extremely rare in pediatric patients, accounting for approximately 5% of all chordomas, with most lesions occupying the cranium. Chordomas also can occupy all levels of the spine, demonstrating a broad spectrum of neurologic presentation. Optimal treatment aims for gross total resection with accompanying radiation therapy to prevent recurrence. Their aggressive and infiltrative nature makes clinical management challenging, involving multiple disciplines and close monitoring to ensure optimal outcomes. This comprehensive review aims to cover the genetics, demographics, pathogenesis, neurologic sequelae, radiological considerations, chemotherapeutic management, surgical management, and post-operative considerations of pediatric chordoma patients.

Chordoma: A Review and Differential Diagnosis

CONTEXT.—

Chordomas are uncommon malignant neoplasms with notochordal differentiation encountered by neuropathologists, bone/soft tissue pathologists, and general surgical pathologists. These lesions most commonly arise in the axial skeleton. Optimal therapy typically involves complete surgical resection, which is often technically difficult owing to the anatomic location, leading to a high rate of recurrence. Lesions have been generally resistant to radiation and chemotherapy; however, experimental studies involving targeted therapy and immunotherapy are currently underway.

OBJECTIVE.—

To summarize the clinical and pathologic findings of the various types of chordoma (conventional chordoma, dedifferentiated chordoma, and poorly differentiated chordoma), the differential diagnosis, and recent advances in molecular pathogenesis and therapeutic modalities that are reliant on accurate diagnosis.

DATA SOURCES.—

Literature review based on PubMed searches containing the term "chordoma" that address novel targeted and immunomodulatory therapeutic modalities; ongoing clinical trials involved in treating chordoma with novel therapeutic modalities identified through the Chordoma Foundation and ClinicalTrials.gov; and the authors' practice experience combined with various authoritative texts concerning the subject.

CONCLUSIONS.—

Chordoma is a clinically and histologically unique malignant neoplasm, and numerous diagnostic considerations must be excluded to establish the correct diagnosis. Treatment options have largely been centered on surgical excision with marginal results; however, novel therapeutic options including targeted therapy and immunotherapy are promising means to improve prognosis.

Economics of the Management of Craniospinal Chordoma and Chondrosarcoma and the feasibility of the bundled payment model

BACKGROUND

The Centers for Medicare and Medicaid Services (CMS) created a new reimbursement model "Bundled Payment for Care Improvement (BPCI)" which reimburses providers a predetermined payment in advance to cover all possible services rendered within a certain time window. Chordoma and Chondrosarcoma are locally aggressive malignant primary bony tumors. Treatment includes surgical resection and radiotherapy with substantial risk for recurrence which necessitates monitoring and further treatment. We assessed the feasibility of the BPCI model in these neurosurgical diseases.

METHODS

We selected patients with chordoma/chondrosarcoma from inpatient admission table using the International Classification of Disease, 9th (ICD-9), and 10th (ICD-10) revision codes. We collected the patients' demographics and insurance type at the index hospitalization. We recorded the following outcomes length of stay, total payment, discharge disposition, and complications for the index hospitalization. For post-discharge, we collected the 30 days and 3/6/12 months inpatient admission, outpatient service, and medication refills. Continuous variables were summarized by means with standard deviations, median with interquartile and full ranges (minimum-maximum); Continuous outcomes were compared by nonparametric Wilcoxson rank-sum test. All tests were 2-sided with a significance level of 0.05. Statistical data analysis was performed in SAS 9.4 (SAS Institute, Inc, Cary, NC).

RESULTS

The population size was 2041 patients which included 1412 patients with cranial (group1), 343 patients with a mobile spine (group 2), and 286 patients with sacrococcygeal (group 3) chordoma and chondrosarcoma. For index hospitalization, the median length of stay (days) was 4, 6, and 7 for groups 1, 2, and 3 respectively (P<.001). The mean payments were ($58,130), ($84,854), and ($82,440), for groups 1, 2, and 3 respectively (P=.02). The complication rates were 30%, 35%, and 43% for groups 1, 2, and 3 respectively (P<.001). Twelve months post-discharge, the hospital readmission rates were 44%, 53%, and 65% for groups 1, 2, and 3, respectively (P<.001). The median payments for this period were ($72,294), ($76,827), and ($101,474), for groups 1, 2, and 3, respectively (P <.001).

CONCLUSION

The management of craniospinal chordoma and chondrosarcoma is costly and may extend over a prolonged period. The success of BPCI requires a joint effort between insurers and hospitals. Also, it should consider patients' comorbidities, the complexity of the disease. Finally, the adoptionof quality improvement programs by hospitals can help with cost reduction.

[Chordoma: is there a molecular basis for diagnosis and treatment?]

Chordomas are malignant bone tumours with a reported annual incidence of 0.08 per 100,000 cases. They show a notochordal differentiation and are characterised by their nuclear expression of brachyury (TBXT). Chordomas are localised in the axial skeleton, where they occur from the clivus to the sacrococcygeal region. They are slow growing, locally destructive tumours, and are often not diagnosed until they have reached an advanced stage. Putative precursor-lesions are benign notochordal cell lesions, which are microscopically small and intraosseous. Different histological chordoma subtypes exist, which differ in their prognosis. To date, there are no known recurrent genetic drivers for this disease. Brachyury seems to play a key role in the pathogenesis of chordoma, though the detailed mechanism still needs to be elucidated. Surgical en bloc resection with negative margins is the only curative treatment for this disease. High-dose irradiation, particularly with protons and carbon ions, is a therapeutic alternative in cases of inoperable tumours. Currently, there is no approved medical treatment for chordoma. Clinical trials exploring additional therapeutic modalities are ongoing.

Early results and volumetric analysis after spot-scanning proton therapy with concomitant hyperthermia in large inoperable sacral chordomas

OBJECTIVE

Large inoperable sacral chordomas show unsatisfactory local control rates even when treated with high dose proton therapy (PT). The aim of this study is assessing feasibility and reporting early results of patients treated with PT and concomitant hyperthermia (HT).

METHODS:

Patients had histologically proven unresectable sacral chordomas and received 70 Gy (relative biological effectiveness) in 2.5 Gy fractions with concomitant weekly HT. Toxicity was assessed according to CTCAE_v4. A volumetric tumor response analysis was performed.

RESULTS:

Five patients were treated with the combined approach. Median baseline tumor volume was 735 cc (range, 369-1142). All patients completed PT and received a median of 5 HT sessions (range, 2-6). Median follow-up was 18 months (range, 9-26). The volumetric analysis showed an objective response of all tumors (median shrinkage 46%; range, 9-72). All patients experienced acute Grade 2-3 local pain. One patient presented with a late Grade 3 iliac fracture.

CONCLUSION

Combining PT and HT in large inoperable sacral chordomas is feasible and causes acceptable toxicity. Volumetric analysis shows promising early results, warranting confirmation in the framework of a prospective trial.

ADVANCES IN KNOWLEDGE:

This is an encouraging first report of the feasibility and early results of concomitant HT and PT in treating inoperable sacral chordoma.

The clinical outcomes for chordomas in the cranial base and spine: A single center experience

Owing to the special growth pattern of chordomas and the limited treatment options currently available, the treatment of chordoma still remains difficult. In this study, we hope to further clarify the relationship between surgical treatment and radiotherapy of chordoma and disease progression.All patients with a primary histopathological diagnosis of clival or spinal chordomas recorded in our institution between 1976 and 2017 were examined.A total of 60 patients (location: skull base/clival, n = 24; vertebral column, n = 5; sacrum, n = 31) had a mean follow-up time of 7.7 years (range 12 months-35 years). Compared with patients who received subtotal resection (n = 5, 5-year and 10-year survival = 61% and 39%, respectively), the annual survival rate of patients who received total resection (n = 55, 5-year and 10-year survival = 67%, respectively) was significantly higher. The overall 10-year survival rate (58%) of patients treated with surgery alone was significantly different from those treated with a combination of surgery and radiation (73%). The long-term prognosis of sacral chordoma was the worst (10-year survival rate = 48%).The best treatment strategy for improved long-term survival in chordoma was a combination of surgical resection and radiation therapy. Adjuvant radiotherapy for chordoma significantly improves disease-free survival, although the long-term survival benefit remains to be determined. A worse prognosis and poor long-term survival are seen in sacral chordomas.

Chordoma arising from benign multifocal notochordal tumors

This case reports a 25-year-old woman initially diagnosed with adjacent benign notochordal cell tumors (BNCTs) of L3 and L4 based on needle biopsy of L3 and stable imaging over a 3-year period who was ultimately found to have a chordoma arising from a BNCT at L3. It illustrates the potential relationship between benign and malignant notochordal tumors and the difficulty in distinguishing them by clinical, radiological, and even histopathological means.

Maximum surgical resection and adjuvant intensity-modulated radiotherapy with simultaneous integrated boost for skull base chordoma

BACKGROUND

Local recurrence is common after surgical resection of clivus chordoma. We report the results of maximum surgical resection followed by intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB).

METHODS

We reviewed 14 consecutive clivus chordoma cases undergoing postoperative IMRT-SIB using the institutional protocol between 2005 and 2013. Total and near-total resections were achieved in 11 patients (78.6 %), partial in 2 patients (14.3 %), and 1 patient (7.1 %) received RT for recurrent tumor after total resection. Gross residual or the high-risk area defined the planning target volume (PTV)1; PTV2 was the postoperative tumor bed plus a 3-5-mm margin, and PTV3 was PTV2 plus a 5-10 mm margin. A moderate hypofractionation schedule was used: doses to PTV1, PTV2 and PTV3 were 3.9 Gy, 3.15 Gy and 2.8 Gy through 15 fractions for the first two patients, and the rest received 2.5 Gy, 2.2 Gy and 1.8 Gy through 25 fractions. The biologically equivalent dose in 2-Gy fractions (EQD2) was 65-68 Gy for PTV1, 52-56 Gy for PTV2, and 44.3-44.8 Gy for PTV3.

RESULTS

Median follow-up was 41 months. Eight patients were free of disease for median 42.5 months (range 23-91 months), four patients had stable disease for median 60.5 months (range 39-113 months), and 1 patient showed partial response for 38 months after RT. Local progression was seen in one patient who received EQD2 67.8 Gy after partial resection. Estimated 5-year progression-free and overall survival rates were 92.9 %. Surgery improved the neurologic deficit in six patients, and IMRT-SIB was well tolerated without lasting toxicity.

CONCLUSION

Our experience suggests that maximum resection and high-dose IMRT-SIB can achieve local control without significant morbidities.

Multidisciplinary management of clival chordomas; long-term clinical outcome in a single-institution consecutive series

OBJECTIVE

Chordomas of the skull base have high recurrence rates even after radical resection and adjuvant radiotherapy. We evaluate the long-term clinical outcome using multidisciplinary management in the treatment of clival chordomas.

METHODS

Between 1984 and 2015, 22 patients diagnosed with an intracranial chordoma were treated at the Karolinska University Hospital, Stockholm, Sweden. Sixteen of 22 were treated with Gamma Knife radiosurgery (GKRS) for tumour residual or progression during the disease course. Seven of 22 received adjuvant fractionated radiotherapy and 5 of these also received proton beam radiotherapy.

RESULTS

Fifteen of 22 (68%) patients were alive at follow-up after a median of 80 months (range 22-370 months) from the time of diagnosis. Six were considered disease free after >10-year follow-up. The median tumour volume at the time of GKRS was 4.7 cm³, range 0.8-24.3 cm³. Median prescription dose was 16 Gy, range 12-20 Gy to the 40-50% isodose curve. Five patients received a second treatment with GKRS while one received three treatments. After GKRS patients were followed with serial imaging for a median of 34 months (range 6-180 months). Four of 16 patients treated with GKRS were in need of a salvage microsurgical procedure compared to 5/7 treated with conventional or proton therapy.

CONCLUSION

After surgery, 7/22 patients received conventional and/or photon therapy, while 15/22 were treated with GKRS for tumour residual or followed with serial imaging with GKRS as needed upon tumour progression. With this multidisciplinary management, 5- and 10-year survivals of 82% and 50% were achieved, respectively.

Paediatric Chordomas

Paediatric chordomas are rare malignant tumours arising from primitive notochordal remnants with a high rate of recurrence. Only 5 % of them occur in the first two decades such less than 300 paediatric cases have been reported so far in the literature. In children, the average age at diagnosis is 10 years with a male-to-female ratio closed to 1. On the opposite to adults, the majority of paediatric chordomas are intracranial, characteristically centered on the sphenooccipital synchondrosis. Metastatic spread seems to be the prerogative of the under 5-year-old children with more frequent sacro-coccygeal locations and undifferentiated histology. The clinical presentation depends entirely on the tumour location. The most common presenting symptoms are diplopia and signs of raised intracranial pressure. Sacrococcygeal forms may present with an ulcerated subcutaneous mass, radicular pain, bladder and bowel dysfunctions. Diagnosis is suspected on computerised tomography showing the bone destruction and with typically lobulated appearance, hyperintense on T2-weighted magnetic resonance imaging. Today, treatment relies on as complete surgical resection as possible (rarely achieved because of frequent invasiveness of functional structures) followed by adjuvant radiotherapy by proton therapy. The role of chemotherapy has not been proven. Prognosis is better than in adults and depends on the extent of surgical resection, age and histology subgroup. Biological markers are still lacking to improve prognosis by developing targeted therapy.

Overexpression of the BMP4/SMAD signaling pathway in skull base chordomas is associated with poor prognosis

Chordomas are rare, locally invasive tumors with characteristic expression of the T-box transcription factor Brachyury. Little is yet known of the molecular events involved in the development of these tumors. Bone morphogenesis protein 4 (BMP4) signaling, which acts upstream of Brachyury in embryonic development, has been implicated in carcinogenesis in multiple malignancies. To explore the role of the canonical BMP4/SMAD signaling pathway in the pathogenesis of chordoma, we investigated, in 40 skull base chordomas, the expression of three major components of the signaling axis: BMP4, phospho-SMAD5 and SMAD4. Immunostaining revealed positive expression in 70%, 52.5% and 90% of cases, respectively. Eighteen (45%) of patients exhibited concurrent positive expression of these markers, which we defined as "high" expression of the BMP4/SMAD signaling pathway. Interestingly, when we compared the pattern of expression with clinicopathological parameters, we found that high expression of the pathway was more often observed in larger tumors (≥ 4 cm) than smaller ones (P = 0.010), and correlated significantly with dural invasion (P = 0.024). The Kaplan-Meier log-rank test showed that the 5-year overall survival rate for patients with high expression of the pathway was significantly lower than those with low expression (71.4% vs. 90.2%, P = 0.010). In conclusion, our results demonstrate for the first time that overexpression of the BMP4/SMAD signaling pathway could predict poor clinical outcome in skull base chordomas, suggesting activation of this pathway is involved in chordoma pathogenesis.

Phase I Trial of a Yeast-Based Therapeutic Cancer Vaccine (GI-6301) Targeting the Transcription Factor Brachyury

The nuclear transcription factor brachyury has previously been shown to be a strong mediator of the epithelial-to-mesenchymal transition (EMT) in human carcinoma cells and a strong negative prognostic factor in several tumor types. Brachyury is overexpressed in a range of human carcinomas as well as in chordoma, a rare tumor for which there is no standard systemic therapy. Preclinical studies have shown that a recombinant Saccharomyces cerevisiae (yeast) vaccine encoding brachyury (GI-6301) can activate human T cells in vitro. A phase I dose-escalation (3+3 design) trial enrolled 34 patients at 4 dose levels [3, 3, 16, and 11 patients, respectively, at 4, 16, 40, and 80 yeast units (YU)]. Expansion cohorts were enrolled at 40- and 80-YU dose levels for analysis of immune response and clinical activity. We observed brachyury-specific T-cell immune responses in the majority of evaluable patients despite most having been heavily pretreated. No evidence of autoimmunity or other serious adverse events was observed. Two chordoma patients showed evidence of disease control (one mixed response and one partial response). A patient with colorectal carcinoma, who enrolled on study with a large progressing pelvic mass and rising carcinoembryonic antigen (CEA), remains on study for greater than 1 year with stable disease, evidence of decreased tumor density, and decreased serum CEA. This is the first-in-human study to demonstrate the safety and immunogenicity of this therapeutic cancer vaccine and provides the rationale for exploration in phase II studies. A randomized phase II chordoma study is now enrolling patients.

Experimental study on differences in clivus chordoma bone invasion: an iTRAQ-based quantitative proteomic analysis

Although a bone tumor, significant differences in the extent of bone invasion exist in skull base chordoma, which directly affect the extent of surgical resection, and have an impact on its prognosis. However, the underlying mechanism of the phenomenon is not clearly understood. Therefore, we used an iTRAQ-based quantitative proteomics strategy to identify potential molecular signatures, and to find predictive markers of discrepancy in bone invasion of clivus chordoma. According to bone invasive classification criteria, 35 specimens of clivus chordoma were calssified to be either endophytic type (Type I) or exophytic type (Type II). An initial screening of six specimens of endophytic type and six of exophytic was performed, and 250 differentially expressed proteins were identified. Through the GO and IPA analysis, we found evidence that the expression of inflammatory activity-associated proteins up-regulated in endophytic type, whereas the expression of cell motility-associated proteins up-regulated in exophytic ones. Moreover, TGFβ1 and mTOR signal pathway seemed to be related with bone invasion. Thus, TGFβ1, PI3K, Akt, mTOR, and PTEN were validated in the following 23 samples by immune histochemistry and Western blot. The expression levels of TGFβ1 and PTEN were significantly lower in the endophytic type than in the exophytic ones. It was found that TGFβ1 may play an important role in its bone invasion. The mechanisms may be related with conducting an increased inflammatory cell response and a decline in cytoskeletal protein expression. PTEN is confirmed to be associated with the degree of bone invasion. The PI3K/AKT/mTOR signaling pathway might be associated with the bone invasion, but still needs a larger sample size to be verified These results, for the first time, not only demonstrate the biological changes that occur in different growth patterns from the perspective of proteomics, but also provide novel markers that may help to reveal the mechanisms behind clivus chordomas.

The biological basis for modern treatment of chordoma

Chordomas are rare malignant tumors arising in bone of the spheno-occiput, sacrum, and vertebral column which can cause neurological deficit. Current management of chordoma involves safe resection followed by radiation therapy. However, surgical resection is often subtotal and chordoma often recurs despite optimal therapy. Despite years of effort, effective adjuvant therapy for denovo, recurrent and metastatic chordoma are absent and 5-year survival is at best 65%. While no chemotherapeutic agent has been demonstrated to be effective against chordoma in vivo, a greater understanding of the genetics and molecular biology of chordoma is opening up avenues of investigation towards the rational development of targeted therapies. Although enthusiasm for the use of already established or new investigational agents will increase with greater understanding of chordoma biology, laboratory studies of these agents are important prior to incorporation into clinical human trials. The authors review the current state of knowledge regarding chordoma and offer insight into potential new therapies for this rare and challenging tumor.

[Particle beam radiotherapy with a surgical spacer placement for unresectable sacral chordoma]

Sacral chordomas constitute more than half of all chordomas and have a slower local growth than other bone malignant tumors. Although complete radical resection produces a longer local control and disease-free survival at the initial visit, chordomas are already often too large for complete resection to be possible. Particle radiotherapy consisting of proton and carbon-ion is a promising new modality which has an inherent anti-tumor effect against many types of malignancies. However, the application of particle radiotherapy for tumors adjacent to the gastrointestinal tract like sacral chordoma is restricted because the tolerance dose of the intestine is extremely low. A novel two-step treatment was developed with surgical spacer placement and subsequent proton radiotherapy to administer particle radiotherapy with curative intent. This report presents a case of a patient with a huge sacral chordoma treated by this method. This new strategy may potentially be an innovative and standard therapy for unresectable sacral chordoma in the near future.

Cytologic diagnosis of chordoma in a peritoneal effusion: a case report

BACKGROUND

Chordoma, a distinct malignant neoplasm arising from the remnants of the notochord, occurs mostly in patients in the fifth to seventh decade of life. Metastasis occurs in 20-30% of cases. The most common metastatic sites are lungs and, less commonly, other bones and visceral organs. The cytologic features of chordoma in both primary and metastatic foci have been described for specimens obtained by fine needle aspiration biopsy. A few cases have been reported in the sputum and the cerebrospinal fluid.

CASE

A 57-year-old man presented with metastatic chordoma diagnosed in a peritoneal effusion. Cytospin slides of the effusion showed numerous individual and clusters of polygonal, round epithelial cells with a background of myxoid chondroid substance, which stained metachromatic on Diff-Quik slides. Many diagnostic physaliphorous cells were present and characterized by abundant intracytoplasmic vacuoles of various sizes. The nuclei were monotonous, with minimal anisonucleosis. The nuclei had evenly dispersed chromatin with occasional small, eosinophilic nucleoli. The nuclear membranes were smooth, with focal indentation. The differential diagnosis included an adenocarcinoma and metastatic chordoma. Immunohistochemistry applied to the cell block showed that the neoplastic cells were positive for cytokeratin and S-100 protein.

CONCLUSION

The clinical history with immunohistochemical profiles helped confirm the diagnosis of metastatic chordoma.

Skull base chordomas: efficacy of surgery followed by carbon ion radiotherapy

BACKGROUND

Skull base chordomas are challenging to treat because of their invasive nature, critical location, and aggressive recurrence. We report the effectiveness of combined radical skull base surgery with carbon ion radiotherapy for treating skull base chordomas.

METHODS

Between November 1996 and August 2007, 32 patients (12 males and 20 females; mean age at initial presentation 41.4 years, range, 10-75 years) with skull base chordomas underwent 59 operations. Sub-total resection (resection of >90% of the pre-operative tumour volume) was achieved in 24 out of 59 (40.7%) operations. After surgical excision, 9/32 (28.1%) patients underwent adjuvant carbon ion radiotherapy. The patients were followed up for a mean period of 36.3 months (range, 3-93 months) from the initial presentation.

FINDINGS

Fifty percent of the patients had to be re-treated due to tumour regrowth during the follow-up period. Thus far, 3 patients have died from the neoplasms. The overall 7 year survival rate of 9 patients who underwent carbon ion radiotherapy was 85.7%. The rate was higher compared to that of others (76.4%). The 3 year recurrence free survival rates of carbon ion therapy treated group was 70.0%, being higher than that of the other groups treated with radiotherapy or untreated (57.1%, and 7.1% respectively). Log-rank analysis showed a significant difference in the recurrence free survival rates between the group treated with adjunctive carbon ion radiotherapy and the untreated group (P = 0.001146).

CONCLUSIONS

Surgical removal of the tumour around the brainstem and the optic nerve combined with post-operative carbon ion radiotherapy will improve the survival rate and quality of life of patients with complicated skull base chordomas.

Thoracic chordoma: review and role of FDG-PET

Chordoma is an uncommon primary bone tumor and the thoracic spine is the least common of all sites for a chordoma. It may recur despite slow-growing nature. Precise literature review will be performed and possible use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of both primary and recurrent diagnosis will be discussed. This article presents the case of a 73-year-old male patient who complained of back pain. Magnetic resonance (MR) imaging, computed tomography (CT) and FDG-PET demonstrated thoracic lesion and biopsy revealed chordoma. The patient was operated on and histological findings showed the tumor was chondroid chordoma. He suffered recurrence after 7 months by FDG-PET. He received 6,000 rads radiation therapy and is neurological free but, suffered backache 15 months after initial diagnosis. Only 12 cases including this case were reported precisely and this is the first report of FDG-PET for both initial and recurrent diagnosis of chordoma.

Chordoma and chondrosarcoma gene profile: implications for immunotherapy

Chordoma and chondrosarcoma are malignant bone tumors characterized by the abundant production of extracellular matrix. The resistance of these tumors to conventional therapeutic modalities has prompted us to delineate the gene expression profile of these two tumor types, with the expectation to identify potential molecular therapeutic targets. Furthermore the transcriptional profile of chordomas and chrondrosarcomas was compared to a wide variety of sarcomas as well as to that of normal tissues of similar lineage, to determine whether they express unique gene signatures among other tumors of mesenchymal origin, and to identify changes associated with malignant transformation. A HG-U133A Affymetrix Chip platform was used to determine the gene expression signature in 6 chordoma and 14 chondrosarcoma lesions. Validation of selected genes was performed by qPCR and immunohistochemistry (IHC) on an extended subset of tumors. By unsupervised clustering, chordoma and chondrosarcoma tumors grouped together in a genomic cluster distinct from that of other sarcoma types. They shared overexpression of many extracellular matrix genes including aggrecan, type II & X collagen, fibronectin, matrillin 3, high molecular weight-melanoma associated antigen (HMW-MAA), matrix metalloproteinase MMP-9, and MMP-19. In contrast, T Brachyury and CD24 were selectively expressed in chordomas, as were Keratin 8,13,15,18 and 19. Chondrosarcomas are distinguished by high expression of type IX and XI collagen. Because of its potential usefulness as a target for immunotherapy, the expression of HMW-MAA was analyzed by IHC and was detected in 62% of chordomas and 48% of chondrosarcomas, respectively. Furthermore, western blotting analysis showed that HMW-MAA synthesized by chordoma cell lines has a structure similar to that of the antigen synthesized by melanoma cells. In conclusion, chordomas and chondrosarcomas share a similar gene expression profile of up-regulated extracellular matrix genes. HMW-MAA represents a potential useful target to apply immunotherapy to these tumors.

Chordoma: the nonsarcoma primary bone tumor

Chordomas are rare, slowly growing, locally aggressive neoplasms of bone that arise from embryonic remnants of the notochord. These tumors typically occur in the axial skeleton and have a proclivity for the spheno-occipital region of the skull base and sacral regions. In adults, 50% of chordomas involve the sacrococcygeal region, 35% occur at the base of the skull near the spheno-occipital area, and 15% are found in the vertebral column. Craniocervical chordomas most often involve the dorsum sella, clivus, and nasopharynx. Chordomas are divided into conventional, chondroid, and dedifferentiated types. Conventional chordomas are the most common. They are characterized by the absence of cartilaginous or additional mesenchymal components. Chondroid chordomas contain both chordomatous and chondromatous features, and have a predilection for the spheno-occipital region of the skull base. This variant accounts for 5%-15% of all chordomas and up to 33% of cranial chordomas. Dedifferentiation or sarcomatous transformation occurs in 2%-8% of chordomas. This can develop at the onset of the disease or later. Aggressive initial therapy improves overall outcome. Patients who relapse locally have a poor prognosis but both radiation and surgery can be used as salvage therapy. Subtotal resection can result in a stable or improved status in as many as 50% of patients who relapse after primary therapy. Radiation therapy may also salvage some patients with local recurrence. One series reported a 2-year actuarial local control rate of 33% for patients treated with proton beam irradiation.

Malignant tumors of the anterior skull base

BACKGROUND

Cancers of the paranasal sinuses or nasal cavity are the most common malignant tumors of the anterior skull base. Several types of tumors occur in this location, including cancers of endodermal, mesodermal, and epidermal origins. Although anterior skull base surgery is a relatively recent approach in treating these tumors, widespread changes have already occurred in procedural methods and treatment goals.

METHODS

We review the tumor types that occur in the anterior skull base and discuss the current treatment options, including multimodal therapy and the team approach to surgery. Surgical techniques are also described.

RESULTS

Management of anterior skull base cancer is complex due to the anatomic detail of the region and the variety of cancers that occur in this area. Currently, the "gold standard" for surgery is the anterior craniofacial approach. Combined with adjuvant radiation therapy, 5-year disease-free survival rates have increased to 50%, with some tumors such as adenocarcinomas and esthesioneuroblastomas reaching up to 80% 5-year survival rates. Potential complications include cerebrospinal fluid leakage, meningitis, abscess formation, and pneumocephalus.

CONCLUSIONS

Treatment of anterior skull base cancer is complex due to the significant anatomic detail of the region and the variety of cancers that occur in this area. Multimodal therapy through a team approach is the optimal management approach for these tumors.

[Factors influencing the survival of patients with skull base chordoma]

OBJECTIVE

To investigate the factors influencing the survival of patients with skull base chordoma.

METHODS

The clinical data of 79 patients with skull base chordoma, with a male/female ratio of 1.3:1, who received operations in Tiantan Hospital between May 1993 and June 2005 were selected. Thirteen factors, including gender, age, main symptoms, positive signs, bulk of the tumor, having received operation or radiotherapy before admission, grouping and staging of the tumor's location, and texture, adherence, pathological and resection grouping of the lesion, underwent Kaplan-Meier single factor analysis, Cox regression, and t-test.

RESULTS

Kaplan-Meier single factor analysis displayed that having received operation or radiotherapy before admission, adherence, pathological and resection groupings of the lesion were the risk factors of the patients' life span (all P < 0.01). Cox multiple factor analysis showed that the all of the above factors except adherence grouping of the lesion had statistical significance on the patients' life span (all P < 0.01).

CONCLUSION

Having received operation or radiotherapy before admission, adherence, pathological and resection groupings of the lesion influence the prognosis of skull base chordoma.

Les chordomes

Chordoma is a rare bone tumor, believed to derive from notochordal rests, which generally arises at the two extremities of axial skeleton. We present a literature review on chordomas. Diagnosis has been greatly improved by MRI and immunohistochemistry. Conversely, complementary immunohistochemistry, cytometry and cytogenetic techniques have failed to improve prognosis evaluation. Radical surgery with free surgical margins is the most accurate curative treatment. Progress in radiotherapy should offer new therapeutic perspectives in the future. The recognition of new entities such as giant notochordal rest or hamartoma, and notochordal cells benign tumor, can lead to confusion since there is no consensus regarding their nature and whether or not they correspond to chordoma precursors. Prudence should be the rule in order to avoid overtreatment.

Extra-Axial Chordoma

Chordomas are low-grade malignant tumors of bone that occur almost exclusively in the axial skeleton. Other neoplasms with a similar histologic picture but an extra-axial location have been described, including parachordoma, myxoid chondrosarcoma, and extra-axial chordoma. We herein present another case of the rare extra-axial chordoma. A 41-year-old woman developed an 8.3 cm mass in the pubic bone. The gross, microscopic, and immunohistochemical findings were identical to those of a classic chordoma. Parachordoma and myxoid chondrosarcoma were excluded from the differential diagnosis. Five previously reported cases of extra-axial chordoma were reviewed and found also to demonstrate clinical and pathologic features specific to chordoma, despite arising in an extra-axial location. Although rare, extra-axial chordoma does exist and should be recognized and managed in a similar fashion to its well-described counterpart. It must be differentiated from other histologic mimics, because the treatment and prognosis can differ significantly.

Metastatic disease from spinal chordoma: a 10-year experience

OBJECT

Metastastic lesions have been reported in 5 to 40% of patients with spinal and sacrococcygeal chordoma, but few contemporary series of chordoma metastastic disease exist in the literature. Additionally, the outcome in patients with chordoma-induced metastastic neoplasms remains unclear. The authors performed a retrospective review of the neurosurgery database at the University of Texas M. D. Anderson Cancer Center in Houston to determine the incidence of metastatic disease in a contemporary series of spinal and sacrococcygeal chordoma as well as to determine the outcomes.

METHODS

Thirty-seven patients underwent surgery for spinal and sacrococcygeal chordoma between June 1, 1993, and March 31, 2004. All records were reviewed, and appropriate statistical analyses were used to compare patient data for preoperative characteristics, treatments, and outcomes. The authors identified seven patients (19%) in whom metastatic disease developed; in three the disease had metastasized to the lungs only, in two to the lungs and liver, and in two to distant locations in the spine. There were no significant differences in age, sex, tumor location, or history of radiation treatments between patients with and those without metastases. In cases with local recurrent tumors, metastastic disease was more likely to develop than in those without recurrence (28 compared with 0%, respectively; p = 0.07). In two (12%) of 17 patients who underwent en bloc resection, metastatic disease developed, whereas it developed in five (25%) of 20 patients treated by curettage (p = 0.42). The median time from first surgery to the appearance of metastatic disease, as calculated using the Kaplan-Meier method, was 143.4 months (95% confidence interval [CI] 66.8-219.9). The median survival duration of patients with metastatic disease after the first surgery was 106 months (95% CI 55.7-155.7), and this did not differ significantly from that in patients in whom no metastases developed (p = 0.93).

CONCLUSIONS

Spinal chordoma metastasized to other locations in 19% of the patients in this series. In patients with local disease recurrence, metastatic lesions are more likely to develop. Metastatic lesions were shown to be aggressive in some cases. Surgery and chemotherapy can play a role in controlling metastatic disease.

Treatment of recurrent chordomas by percutaneous ethanol injection therapy and radiation therapy

We report a case of recurrent sacral chordomas that have been successfully controlled by the combination therapy of percutaneous ethanol injection therapy (PEIT) and radiation therapy in a 71-year-old man. PEIT may be one of the adjuvant therapies for recurrent chordomas.

Chordoma of the mobile spine: fifty years of experience

STUDY DESIGN

A consecutive series of 52 chordomas of the mobile spine observed over a 50-year period includes a retrospective review of 15 cases treated prior to 1991 and a prospective group of 37 cases treated from 1991 to 2002.

OBJECTIVES

This series reviews epidemiologic issues as well as clinical patterns of spinal chordomas. We attempt to correlate tumor extent, treatment, and outcomes over time.

SUMMARY OF BACKGROUND DATA

Chordoma is the most frequent primary tumor of the mobile spine. Due to slow growth, both initial symptoms and recurrences after treatment arise later, making it difficult to evaluate the effectiveness of treatment protocols.

METHODS

A prospective series of 37 cases is compared with a retrospective group of 15 patients observed between 1954 and 1991. In the prospective study, all patients had imaging studies, and oncologic and surgical staging. When en bloc resection was not feasible, intralesional extracapsular excision was combined with radiation therapy. The prospective patients were clinically evaluated and imaged. Patients in the retrospective group were evaluated by chart and available images; of these, only one en bloc resection (intralesional margin) was performed. Survivors were all evaluated clinically and had radiographic studies.

RESULTS

Forty-eight patients were available for long-term follow-up. Four died due to post-operative complications, and six due to disease less than 2 years after treatment. Forty-two patients were followed over 2 years; 26 patients had over 5 years follow-up. All patients having radiation alone, intralesional excision, or a combination had recurrences in less than 2 years, and died in some cases after a long survival with symptomatic disease. Intralesional extracapsular excision with radiation had a high rate of recurrence (12 of 16 at average 30 months), but 3 patients are continuously disease-free (CDF) at mean 52 months and 5 are alive with disease at average 69 months (ranging 24 to 146). Twelve of 18 patients having en bloc resection are CDF at average 8 years (48 to 155 months). The remaining 6 recurred and of these 1 died. All of these (6) had been previously treated and/or had en bloc resections with contaminated margins.

CONCLUSIONS

The only treatment protocol associated with CDF at follow-up longer than 5 years is margin-free en bloc resection.

Radiofrequency ablation in palliative supportive care: early clinical experience

We report our early experience with radiofrequency ablation (RFA) in palliative supportive care. The medical files of eight patients were retrospectively reviewed. Four patients had a renal tumor, and nephrectomy was contraindicated in each patient since they had a poor general status. The fifth patient had a local recurrence in the site of a previous nephrectomy with a pancreatic tail extension, and surgical resection was contraindicated because of abdominal carcinomatosis. Two other patients had bone metastasis, one with a painful metastasis of mammary carcinoma in the head of the humerus resistant to radiotherapy, and the other with metastasis of the tibia of cutaneous melanoma. The last patient had a local recurrence of a sacral chordoma. Management, outcomes and complications were evaluated with 13.1+/-0.3 months follow-up. All five patients with renal carcinomas did not have local recurrence. The two patients treated for bone metastases had no pain 8 weeks after RFA and remained stable over time. One complication occurred 2 months after using the procedure to treat the chordoma, and this patient was hospitalized for a fistula between the sigmoid and hypogastric artery false aneurysm and subsequently died. In conclusion, RFA can be a safe and useful adjuvant treatment in supportive care or unresponsive cancer pain patients. However, the destruction of tumoral tissues in contact with sensitive structures using RFA should be done with caution due to potentially severe complications.

Transient tetraplegia and vegetative dysfunction depending on cervical positioning caused by a cervical spinal chordoma

A 39-year-old man with acquired torticollis suffering from cervicobrachialgia and neurological deficits is presented. Due to a change in head position a transient reproducible tetraplegia and severe vegetative dysfunctions were caused. The origin of this uncommon serious combination of symptoms and signs was a chordoma of the upper cervical spine. After surgical decompression the patient was free of neurological deficit and pain. Review of the literature did not reveal any similar case.

Recurrent and metastatic clivus chordoma: systemic palliative therapy retards disease progression

We report on a male patient with progressive and metastatic clivus chordoma treated over a period of 9 years by a multidisciplinary approach. Within the first 4 years, the patient underwent surgery four times. Thereafter, he received radiotherapy and subsequent chemotherapy. Stabilization of disease was achieved repeatedly for variable periods under local radiotherapy, systemic chemotherapy, immunomodulatory and anti-angiogenic therapy with isotretinoin and interferon-alpha, followed by thalidomide. Due to the occurrence of brain and lung metastases 8 years after initial diagnosis, liposomal doxorubicin was added to thalidomide. At the last follow-up control the patient had stable disease, with no progression of the intracranial tumor and regression of pulmonary metastases. He is in a good physical, psychological and neurological condition with a Karnofsky score of 80. Our observations show that multimodal therapy including a systemic palliative approach is associated with long quiescent intervals in recurrent chordoma and with regression of its metastases. Use of substances with high efficacy on tumor tissue and low toxicity, allowing long-term administration, seems promising in similar situations.

Alterations of G1-S checkpoint in chordoma

BACKGROUND

To the authors' knowledge, little is known regarding the alterations of G(1)-S checkpoint and their significance in chordoma, a rare bone tumor. The authors investigated the clinicopathologic relevance of cell cycle abnormalities in chordoma.

METHODS

The expression levels of p53, murine double minute 2 (MDM2), retinoblastoma protein (pRb), cyclin D1, p16(INK4a), and p27(Kip1) were investigated using immunohistochemical techniques; p53 mutations were studied by polymerase chain reaction (PCR)-single-strand conformation polymorphism, and mdm2 amplification was analyzed using real-time quantitative PCR. The results were compared with clinicopathologic parameters in 101 lesions.

RESULTS

Approximately 10-45% of primary tumors presented alterations of p53, MDM2, cyclin D1, and pRb proteins; most tumors lacked expression of p16(INK4a) and p27(Kip1). Alterations of p53, MDM2, cyclin D1, and pRb proteins were found to have cooperative effects on both higher proliferative ability (MIB-1 labeling index [LI]) and increased nuclear pleomorphism, a previously described prognostic indicator for patients with chordoma. Multivariate analyses revealed that, among these alterations, p53 overexpression was the only independent factor for higher MIB-1 LI. At the genetic level, mdm2 gene amplification was detected in 15.4% of the lesions but did not correlate with MDM2 overexpression or other clinicopathologic parameters. No p53 mutations were detected in the current series. Survival analysis revealed that p53 overexpression, but no other cell cycle alterations, was associated with a reduced overall survival.

CONCLUSIONS

Accumulation of cell cycle alterations led to an increased MIB-1 LI and nuclear pleomorphism, a previously described prognostic indicator in chordoma. The authors believe that p53 overexpression in particular is associated with an unfavorable prognosis in patients with chordoma.

Compressive optic neuropathy due to orbital metastasis of a sacral chordoma: case report

A 44-year-old man presented with unilateral proptosis and progressively deteriorating vision of his left eye over a 2-week period. He had a history of recurrent sacral chordoma for 1 year that had previously been treated with combined surgical excision, chemotherapy, and radiation therapy. MRI showed compression of the optic nerve by an orbital mass that proved to be an orbital metastasis of his sacral chordoma. The tumor mass was excised subtotally, and adjuvant orbital radiation therapy was administered.

Molecular pathogenesis of skull base tumors

OBJECTIVE

To review contemporary molecular biological literature related to skull base tumor biology and tumorigenesis.

DATA SOURCES

PUBMED and Ovid literature searches were performed using keyword search. Only English language articles published between 1965 and December 4, 2003 were chosen.

STUDY SELECTION AND DATA EXTRACTION

All relevant articles from the past 8 years, as well as landmark articles in years before 1995, were retrieved and reviewed.

CONCLUSION

Consistent progress is being made toward the molecular genetic and biological basis of the most common skull base tumors. An understanding of these mechanisms will aid the neurotologist in future diagnosis and management of the lesions.

Skull base chordoma

PURPOSE

Our purpose was to discuss the optimal treatment and outcomes for patients with skull base chordomas.

METHODS

We reviewed the pertinent literature for this study.

RESULTS

Skull base chordomas usually arise in the clivus and are rarely completely resectable. Therefore, most are treated with radiotherapy (RT). Because of the risk of severe late complications, the dose is often limited with conventional photon RT, and the probability of cure is low. Proton RT alone or combined with photon RT (proton/photon RT) offers the advantage of improved dose distribution and the ability to treat the tumor to a higher dose without exceeding normal tissue tolerance. The 10-year local control rate after proton/photon RT is approximately 40% to 50%. The probability of local control is related to minimum tumor dose and dose inhomogeneity.

CONCLUSIONS

Skull base chordoma is a rare neoplasm that is rarely cured after surgery alone or combined with conventional RT. Proton/photon RT offers the advantage of increasing the tumor dose while minimizing the dose to normal tissues, thus reducing the risk of late complications. The optimal treatment may be photon/proton RT alone or combined with a gross total resection, when feasible.

Cauda equina syndrome caused by primary and metastatic neoplasms

Cauda equina syndrome (CES) is defined as the constellation of symptoms that includes low-back pain, sciatica, saddle anesthesia, decreased rectal tone and perineal reflexes, bowel and bladder dysfunction, and variable amounts of lower-extremity weakness. There are several causes of this syndrome including trauma, central disc protrusion, hemorrhage, and neoplastic invasion. In this manuscript the authors reviewed CES in the setting of both primary and secondary neoplasms. They examined the various primary tumor types in this region as well as those representative of metastatic spread. Both surgical and nonsurgical management in this setting were studied.

Chordomas of the skull base: manifestations and management

PURPOSE OF REVIEW

Chordomas are rare congenital tumors of the midline skull base. They are slow-growing and usually cause symptoms only when they compress a cranial nerve.

RECENT FINDINGS

The MRI will show the lesion with irregular uptake of gadolinium. The only way to define the diagnosis is with tissue, and there are two primary pathologic forms of the disease. Resection approaches vary with extent of disease, surgeon preference, and critical structures involved.

SUMMARY

There is building evidence that proton beam therapy improves survival and duration of a disease-free state.