Imatinib mesylate in chordoma

Systemic therapy for selected skull base sarcomas: Chondrosarcoma, chordoma, giant cell tumour and solitary fibrous tumour/hemangiopericytoma

This review highlights the data currently available on the activity of systemic therapy in chondrosarcoma, chordoma, giant cell tumour of the bone (GCTB) and solitary fibrous tumour, i.e., four rare sarcomas amongst mesenchymal malignancy arising from the skull base.

Two Cases of Dedifferentiated Chordoma in the Sacrum

Dedifferentiated chordoma (DC) is defined as a chordoma containing sarcoma components. DC is distinguished from conventional chordoma by the rapidity of tumor growth and the potential for distant metastasis. We report two cases of DC, which are developed in the sacrum. We reviewed the medical records and imaging studies of 2 patients diagnosed with DC and the literature published. In the first case, percutaneous biopsy revealed that it was conventional chordoma in the sacrum. Patient underwent radiation therapy (RT). Six years after the RT, the tumor recurred. Surgical removal was performed and the recurrent tumor was diagnosed as DC in histopathologic examination. In the second case, a patient underwent gross total resection of sacral tumor, which was diagnosed with conventional chordoma. Aggravated tumor was detected after 4 months, and patient underwent reoperation. The second operation revealed the transformation of the tumor into DC. The survival time of the patients after the diagnosis was 10 and 31 months. Dedifferentiated chordoma is a rare and highly aggressive tumor. De novo type exists, but it usually transformed from recurrent chordoma after surgical resection or radiation.

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.

The molecular aspects of chordoma

Chordomas are one of the rarest bone tumors, and they originate from remnants of embryonic notochord along the spine, more frequently at the skull base and sacrum. Although they are relatively slow growing and low grade, chordomas are highly recurrent, aggressive, locally invasive, and prone to metastasize to the lungs, bone, and the liver. Chordomas highly and generally show a dual epithelial-mesenchymal differentiation. These tumors resist chemotherapy and radiotherapy; therefore, radical surgery and high-dose radiation are the most used treatments, although there is no standard way to treat the disease. The molecular biology process behind the initiation and progression of a chordoma needs to be revealed for a better understanding of the disease and to develop more effective therapies. Efforts to discover the mysteries of these molecular aspects have delineated several molecular and genetic alterations in this tumor. Here, we review and describe the emerging insights into the molecular landscape of chordomas.

Metastatic Chordoma: Report of the Two Cases and Review of the Literature

Chordomas are rare malignant bone tumours with a predilection for the axial skeleton, especially the sacrum and skull base. Median survival in patients with metastatic disease is usually dismal. Treatment is challenging due to the propensity for local recurrence, metastatic disease as well as lack of clear consensus regarding the optimal management. Our case report highlights two cases of sacral chordoma with locally recurrent and widespread metastatic disease, stable on molecular targeted therapy.

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.

Novel targeted therapies in chordoma: an update

Chordomas are rare, locally aggressive skull base neoplasms known for local recurrence and not-infrequent treatment failure. Current evidence supports the role of maximal safe surgical resection. In addition to open skull-base approaches, the endoscopic endonasal approach to clival chordomas has been reported with favorable albeit early results. Adjuvant radiation is prescribed following complete resection, alternatively for gross residual disease or at the time of recurrence. The modalities of adjuvant radiation therapy reported vary widely and include proton-beam, carbon-ion, fractionated photon radiotherapy, and photon and gamma-knife radiosurgery. As of now, no direct comparison is available, and high-level evidence demonstrating superiority of one modality over another is lacking. While systemic therapies have yet to form part of any first-line therapy for chordomas, a number of targeted agents have been evaluated to date that inhibit specific molecules and their respective pathways known to be implicated in chordomas. These include EGFR (erlotinib, gefitinib, lapatinib), PDGFR (imatinib), mTOR (rapamycin), and VEGF (bevacizumab). This article provides an update of the current multimodality treatment of cranial base chordomas, with an emphasis on how current understanding of molecular pathogenesis provides a framework for the development of novel targeted approaches.

Surgical treatment of retrorectal (presacral) tumors

Retrorectal (also known as presacral) tumor (RT) is a rare disease of retrorectal space. They can be classified as congenital, inflammatory, neurogenic, osseous, or miscellaneous. The most common presentation is an asymptomatic mass discovered on routine rectal examination, but certain nonspecific symptoms can be elicited by careful history and physical examination. The primary and only satisfactory treatment is surgery for RTs. Three approaches commonly used for resection are abdominal, transsacral, or a combined abdominosacral approach. Prognosis is directly related primary local control, which is often difficult to achieve for malignant lesions.

Sustained response of a clivus chordoma to erlotinib after imatinib failure

Chordoma is a rare malignant axial tumour that develops from embryonic remnants of the notochord. Surgery and irradiation are the standard initial treatment. However, local recurrence is frequent and cytotoxic chemotherapy is inefficient. Transient activity of imatinib, a platelet-derived growth factor receptor inhibitor, was described in a phase II study. Activity of epidermal growth factor receptor (EGFR) inhibitors (erlotinib, gefitinib) has also been shown in a few recent case reports. We describe a 68-year-old female in whom clivus chordoma recurred after surgery and radiotherapy. The tumour progressed despite imatinib treatment. A partial and sustained response (28+ months) was obtained using erlotinib, an EGFR inhibitor. Erlotinib should be evaluated in a prospective trial investigating new potential therapies against recurrent chordoma.

Combined therapy for distant metastasis of sacral chordoma

Chordomas are known as rare primary malign tumours that have formed from primitive notochord remains. Sacral chordomas grow slowly but locally and aggressively. Chordomas are locally invasive and have low tendency to metastasis and have a poor prognosis in long-term follow-up. Metastasis may be seen in a rate of 5–40% of the chordomas. Metastasis of chordomas is common in liver, lung, lymph nodes, peritoneum, and brain. The treatment approaches, including surgery, have been discussed in the literature before. Susceptibility to radiotherapy and chemotherapy is controversial in these tumours. The success of surgical treatment affects survival directly. In this report, we will report a sacral chordoma case in which an intraperitoneal distant metastasis occurred and discuss the surgical approach.

Isolated liver metastasis of sacrococcygeal chordoma: case report and review of the literature

Chordomas are rare neoplasms arising from notochordal remnants and may develop anywhere in the body while the most common anatomic site is the sacrococcygeal area. The most effective treatment of chordoma is surgery. Chordomas rarely metastasize to lung, bone, soft tissue, liver, lymph nodes, and skin. However, there is currently no standard systemic treatment for advanced stage chordoma. Here, we reported a rare presentation of chordoma patient with liver only metastases and poor prognosis.

[Chordoma]

PURPOSES

To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.

MATERIALS

The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine.

METHODS

In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups.

RESULTS

In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection.

CONCLUSIONS

Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

Surgical treatment of primary malignant tumors of the sacrum

OBJECTIVES

The objective of the authors was to provide an up-to-date review about the epidemiology, diagnosis, and surgical management of the malignant primary sacral tumors.

METHODS

A PubMed search was conducted using a combination of the following items: (('Spinal Neoplasms'[Mesh]) AND 'Sacrum'[Mesh]) NOT ('Metastasis' OR 'Metastases' OR 'Benign'). The literature review and the author's own surgical experiences were used to assess the current treatment strategies of the malignant sacral tumors.

RESULTS

Twenty case series were identified, which studies discuss in detail the surgical strategies, the postoperative complications, the functional and oncologic outcome, and the recurrence-free and disease-specific survival of this rare patient category.

DISCUSSION

Sacral tumors are rare pathologies. Their management generates a complex medical problem, as they usually are diagnosed in advanced stages with extended dimensions involving the sacral nerves and surrounding organs. The evaluation and complex treatment of these rare tumors require a multidisciplinary approach, optimally at institutions with comprehensive care and experience. Although conventional oncologic therapeutic methods should be used as neoadjuvant or adjuvant therapies in certain histological types, en bloc resection with wide surgical margins is essential for long-term local oncologic control. This is often technically difficult to achieve, as just a few centers in the world perform sacral tumor surgeries on a regular basis, and have enough wide experience. Therefore international cooperation and organization of multicenter tumor registries are essential to develop evidence based treatment protocols.

MGMT promoter methylation status in clival chordoma

Chordomas are rare, slow-growing neoplasms, characterized by locally aggressive growth patterns and high local recurrence rates. To the best of our knowledge, the MGMT promoter methylation status has not been studied in a population of patients with chordomas to determine if a biologic rationale exists to support the use of temozolomide. We here show for the first time that methylation of MGMT promoter is present in a significant portion or recurring clival chordomas; on the contrary in clival chordomas without recurrence MGMT promoter was always unmethylated (p = 0.0317). Although these observations need to be confirmed in a larger study population, our results (1) indicate that methylation of MGMT promoter is present in a significant portion of recurring chordomas, and (2) prompt further investigation into the potential role of temozolomide as an adjuvant treatment of these tumors.

A review of the surgical management of sacral chordoma

BACKGROUND

Sacral chordomas are rare low-to-intermediate grade malignant tumours, which arise from remnants of the embryonic notochord. This review explores prognostic factors in the management of sacral chordomas and provides guidance on the optimal treatment regimens based on the current literature.

PATIENTS AND METHODS

Electronic searches were performed using MEDLINE, Embase and the Cochrane library to identify studies on prognostic factors in the management of sacral chordomas published between January 1970 and December 2013. The literature search and review process identified 100 articles that were included in the review article. This included both surgical and non-surgical studies on the management of sacral chordomas.

RESULTS

Sacrectomy with wide resection margins forms the mainstay of treatment but is associated with high risk of disease recurrence and reduced long-term survival. Adequate resection margins may require sacrifice of adjacent nerve roots, musculature and ligaments leading to functional compromise and mechanical instability. Large tumour size (greater than 5-10 cm in diameter), dedifferentiation and greater cephalad tumour extension are associated with increased risk of disease recurrence and reduced survival. Chordomas are poorly responsive to conventional radiotherapy and chemotherapy.

CONCLUSION

Operative resection with wide resection margins offers the best long-term prognosis. Inadequate resection margins, large tumour size, dedifferentiation, and greater cephalad chordoma extension are associated with poor oncological outcomes. Routine long-term follow-up is essential to enable early detection and treatment of recurrent disease.

Surgical Management of Primary and Metastatic Spinal Tumors

Background

The axial skeleton is a common site for primary tumors and metastatic disease, with metastatic disease being much more common. Primary and metastatic spinal tumors have a diverse range of aggressiveness, ranging from benign lesions to highly infiltrative malignant tumors.

Methods

The authors reviewed the results of articles describing the treatment and outcomes of patients with metastatic disease or primary tumors of the spinal column.

Results

En bloc resection is the mainstay of treatment for malignant primary tumors of the spinal column. Intralesional resection is generally appropriate for benign primary tumors. Low-quality evidence supports the use of chemotherapy in select primary tumors; however, radiation therapy is often used for incompletely resected or unresectable lesions. Surgical considerations for the treatment of metastatic disease are more nuanced and require that the health care professional consider patient performance status and the pathology of the primary tumor.

Conclusions

The treatment of metastatic and primary tumors of the spinal column requires a multidisciplinary approach in order to offer patients the best opportunity for long-term survival.

Targeted therapy for sarcomas

Sarcomas are tumors of mesenchymal origin that make up approximately 1% of human cancers. They may arise as primary tumors in either bone or soft tissue, with approximately 11,280 soft tissue tumors and 2,650 bone tumors diagnosed each year in the United States. There are at least 50 different subtypes of soft tissue sarcoma, with new ones described with ever-increasing frequency. One way to look at sarcomas is to divide them into categories on the basis of their genetic make-up. One group of sarcomas has an identifiable, relatively simple genetic signature, such as the X:18 translocation seen in synovial sarcoma or the 11:22 translocation seen in Ewing's sarcoma. These specific abnormalities often lead to the presence of fusion proteins, such as EWS-FLI1 in Ewing's sarcoma, which are helpful as diagnostic tools and may become therapeutic targets in the future. Another group of sarcomas is characterized by complex genetic abnormalities as seen in leiomyosarcoma, osteosarcoma, and undifferentiated sarcoma. It is important to keep these distinctions in mind when contemplating the development of targeted agents for sarcomas. Different abnormalities in sarcoma could be divided by tumor subtype or by the molecular or pathway abnormality. However, some existing drugs or drugs in development may interfere with or alter more than one of the presented pathways.

Targeted therapies for soft-tissue sarcomas

The past several decades have revealed certain challenges that are inherent to soft-tissue sarcomas with regards to devising, testing and setting treatment paradigms for such a rare and heterogeneous malignancy. Despite this, significant advances have been made through the efforts of scientists, clinicians and patients alike. We are now entering a molecular era of cancer and current biotechnology is beginning to unravel the pathogenic enigma of these often devastating tumors. As our understanding of these malignancies improves, so does our list of potential treatment options. The impetus now lies with the medical/scientific community to direct translational research and subsequently the development and clinical testing of novel compounds in a fashion that best serves this unique patient population. To do so, we must continue to integrate the lessons of the past with the resources and promise of the future. This review will outline current areas of therapeutic interest in soft-tissue sarcomas with regard to agents that have reached clinical testing.

Development of transplantable human chordoma xenograft for preclinical assessment of novel therapeutic strategies

BACKGROUND

Chordomas are rare and indolent bone tumors that arise in the skull base and mobile spine. Distant metastases occur in >20% of cases, but morbidity and mortality are mainly related to local relapses that affect the majority of patients. Standard chemotherapy has modest activity, whereas new targeted therapies (alone or in combination) have some activity in controlling disease progression. However, the scarcity of preclinical models capable of testing in vivo responses to these therapies hampers the development of new medical strategies.

METHODS

In this study, 8 chordoma samples taken from 8 patients were implanted in nude mice. Four engrafted successfully and gave rise to tumor masses that were analyzed histologically, by means of fluorescence in situ hybridization and biochemical techniques. The data relating to each of the mouse tumors were compared with those obtained from the corresponding human tumor.

RESULTS

All 4 engraftments retained the histological, genetic and biochemical features of the human tumors they came from. In one epidermal growth factor receptor(EGFR)-positive xenograft, responsiveness to lapatinib was evaluated by comparing the pre- and post treatment findings. The treatment induced a low-level, heterogeneous switching off of EGFR and its downstream signaling effectors.

CONCLUSIONS

Overall, this model is very close to human chordoma and represents a new means of undertaking preclinical investigations and developing tailored therapies.

Development of transplantable human chordoma xenograft for preclinical assessment of novel therapeutic strategies

BACKGROUND

Chordomas are rare and indolent bone tumors that arise in the skull base and mobile spine. Distant metastases occur in >20% of cases, but morbidity and mortality are mainly related to local relapses that affect the majority of patients. Standard chemotherapy has modest activity, whereas new targeted therapies (alone or in combination) have some activity in controlling disease progression. However, the scarcity of preclinical models capable of testing in vivo responses to these therapies hampers the development of new medical strategies.

METHODS

In this study, 8 chordoma samples taken from 8 patients were implanted in nude mice. Four engrafted successfully and gave rise to tumor masses that were analyzed histologically, by means of fluorescence in situ hybridization and biochemical techniques. The data relating to each of the mouse tumors were compared with those obtained from the corresponding human tumor.

RESULTS

All 4 engraftments retained the histological, genetic and biochemical features of the human tumors they came from. In one epidermal growth factor receptor(EGFR)-positive xenograft, responsiveness to lapatinib was evaluated by comparing the pre- and post treatment findings. The treatment induced a low-level, heterogeneous switching off of EGFR and its downstream signaling effectors.

CONCLUSIONS

Overall, this model is very close to human chordoma and represents a new means of undertaking preclinical investigations and developing tailored therapies.

Some Lessons Learned from Imatinib Mesylate Clinical Development in Gastrointestinal Stromal Tumors

Imatinib mesylate is a molecular-targeted agent, shown to be effective in chronic myeloid leukemia and gastrointestinal stromal tumors (GIST). The latter may currently serve as a model on which speculating how the future of molecular-targeted therapy in solid tumors will be. So far, some lessons have been learnt. 1) Molecular-targeted therapy can be effective in the advanced disease setting, resulting in major tumor responses. 2) Patterns of tumor responses may be peculiar, radiologically and pathologically. 3) Anti-tumor activity may be highly predictable by assessing tumor molecular biology. 4) The methodology of clinical development of molecular-targeted agents may differ from standard chemotherapy in some respects, because, say, the preclinical rationale may be stronger, thus increasing the Bayesian prior probability of efficacy, or the optimal dose cannot be determined separately from the assessment of activity and efficacy. 5) Molecular-targeted agents will hardly remain "orphan drugs", if effective. 6) While an obvious impact on survival in the advanced disease setting has been clearly demonstrated, the biologic and clinical impact of molecular-targeted therapy still needs to be elucidated. Its eradicating capabilities, as well as the implications of secondary resistance, are to be understood. 7) Integrated, multimodality approaches, including surgery, may still be of value in the molecular-targeted therapy era.

The evolution of systemic therapy in sarcoma

Approximately 50% of patients with localized soft tissue sarcomas will develop recurrent disease after complete surgical resection, requiring alternative means of treatment. Conventional chemotherapy comprising of doxorubicin and ifosfamide has shown benefit in advanced disease, however, there remains a clear need for more effective, less toxic, therapies for the treatment of this heterogeneous group of mesenchymal malignancies. Recently, greater emphasis has been placed on the underlying biology of individual sarcoma subtypes, with the development and evaluation of novel therapies both in common and in rare subtypes. In addition, there is a greater specificity in the selection of chemotherapy agents based on activity in individual histological subtypes. Despite these advances the management of sarcoma, and in particular of rare subtypes, remains a major challenge. Some histological subtypes are resistant to conventional chemotherapy and patients with these diseases should be offered participation in early phase clinical trials of novel drugs.

[Tumours of the upper cervical spine]

OBJECTIVE

Vertebral tumours arising in the upper cervical spine are rare. We present our experience in managing these neoplasms.

MATERIAL AND METHODS

We retrospectively reviewed the case histories of patients treated at our institution between January 2000 and June 2011.

RESULTS

There were 9 patients with tumours in C1-C2-C3: 2metastases, 3chordomas, 2plasmocytomas, 1chondrosarcoma and 1osteochondroma. All patients complained of neck pain at the time of diagnosis. Three patients underwent an anterior and posterior approach, 3 an exclusively posterior approach and 3 an exclusively anterior surgical approach. Tumour resection was intralesional in 7 cases. Chemo-radiotherapy was used as adjuvant therapy in patients with malignant tumours.

CONCLUSIONS

Vertebral tumours in the upper cervical spine are usually malignant. Achieving en bloc resection is particularly challenging and is technically unfeasible in many cases. This worsens the prognosis and makes adjuvant treatment very important.

Converging paths to progress for skull base chordoma: Review of current therapy and future molecular targets

BACKGROUND

Chordomas of the skull base are rare locally aggressive neoplasms with a predilection for encapsulating critical neurovascular structures, bony destruction and irregular growth patterns, and from which patients succumb to recurrence and treatment failures.

METHODS

A review of the medical literature is performed, using standard search engines and identifying articles related to skull base chordomas, surgery, radiation therapy, chemotherapy, molecular genetics, and prospective trials.

RESULTS

A synthesis of the literature is presented, including sections on pathology, treatment, molecular genetics, challenges, and future directions.

CONCLUSION

Beyond an understanding of the current treatment paradigms for skull base chordomas, the reader gains insight into the collaborative approach applied to orphan diseases, of which chordomas is a prime exemplar.

From notochord formation to hereditary chordoma: the many roles of Brachyury

Chordoma is a rare, but often malignant, bone cancer that preferentially affects the axial skeleton and the skull base. These tumors are both sporadic and hereditary and appear to occur more frequently after the fourth decade of life; however, modern technologies have increased the detection of pediatric chordomas. Chordomas originate from remnants of the notochord, the main embryonic axial structure that precedes the backbone, and share with notochord cells both histological features and the expression of characteristic genes. One such gene is Brachyury, which encodes for a sequence-specific transcription factor. Known for decades as a main regulator of notochord formation, Brachyury has recently gained interest as a biomarker and causative agent of chordoma, and therefore as a promising therapeutic target. Here, we review the main characteristics of chordoma, the molecular markers, and the clinical approaches currently available for the early detection and possible treatment of this cancer. In particular, we report on the current knowledge of the role of Brachyury and of its possible mechanisms of action in both notochord formation and chordoma etiogenesis.

A new surgical technique (modified Osaka technique) of sacral resection by posterior-only approach: description and preliminary results

STUDY DESIGN

Operative technique.

OBJECTIVE

To report a new technique for sacral resection, with short-term preliminary results.

SUMMARY OF BACKGROUND DATA

Although various reports analyzed en bloc excision of sacral tumors, there are still technical problems to improve protection of nerve roots, preserve surrounding structures, and reduce intraoperative bleeding, while maintaining the oncological result.

METHODS

Thirteen patients were resected for their sacrococcygeal tumor by following the described technique. Two patients had undergone previous surgery elsewhere. The sacrum was exposed by a posterior midline incision and complete soft-tissue dissection. Lateral osteotomies were performed through the sacral foramina using a threadwire saw (devised by Tomita and Kawahara) and Kerrison rongeurs, to avoid damage to the sacral roots. After proximal osteotomy, the sacrum was laterally elevated and mobilized to allow dissection of presacral structures. Mean surgical time was 5.5 hours (range; 1.5-8). Mean blood loss was 2961 mL (range; 1000-8000 mL).

RESULTS

Level of resection was proximal in 9 patients and at S3 or below in 4. Margins were wide in 10 patients, marginal in 1, and intralesional in 2. At a mean follow-up of 35.5 months, 9 patients were disease free, while the tumor recurred locally in 4 cases. Complications requiring surgery were seen in 1 case.

CONCLUSION

The reported technique allows wide margins with preservation of roots, and reduction in blood loss and operative time. Indications for posterior-only approach can be extended to resection proximal to S3, when there is minimal pelvic invasion and none or partial involvement of sacroiliac joints. However, the long-term benefits of this technique need to be evaluated.

Skull base chordomas: clinical features, prognostic factors, and therapeutics

Chordomas of the skull base are one of the rarest intracranial malignancies that arise from ectopic remnants of embryonal notochod. The proximity of many chordomas to neurovascular structures makes gross total resection difficult, and the tendency for recurrence leads to the routine use of adjuvant postoperative radiation. Several surgical approaches are used ranging from extensive craniotomies to minimally invasive endonasal endoscopic approaches. In this review, the histopathology and epidemiology, imaging characteristics, surgical approaches, adjuvant therapies, prognostic factors, and molecular biology of chordomas are described.

Chondroid chordoma and nasal adenocarcinoma: an exceptional association

Collision tumors are exceptional, associating two independent tumoral contingents. We report a case of an association of two rare tumors: sinonasal adenocarcinoma and chondroid chordoma. Initially, only adenocarcinoma was diagnosed. The treatment consisted of endoscopic endonasal surgery followed by conventional radiotherapy. After 18 months, a local recurrence was diagnosed after a facial trauma, but the true histology was difficult to assess. The tumor was dual, associating adenocarcinoma and chondroid chordoma, with atypical localization in the ethmoid. Further evolution was particularly aggressive. We discuss the key points of this observation.

Three-level en bloc spondylectomy for chordoma

BACKGROUND

En bloc resection of spinal and sacral chordomas may convey a survival benefit. However, these procedures often are complex and require the surgeon to plan a procedure that results in negative tumor margins, protects vital neurovascular structures, and concludes with a viable biomechanical reconstruction.

OBJECTIVE

We present a case of a 3-level en bloc lumbar spondylectomy and reconstruction.

METHODS

A case of a 45-year-old woman with biopsy-proven exophytic L4 chordoma is presented. The patient underwent successful L3-L5 en bloc spondylectomy and reconstruction over 3 stages.

RESULTS

The patient did well following the procedure, and was neurologically intact at 6-week follow-up.

CONCLUSION

Three-level en bloc spondylectomy with lumbopelvic reconstruction is a challenging yet feasible procedure.

Novel therapeutic targets in chordoma

INTRODUCTION

Chordomas are malignant bone tumors arising from notochordal remnants. They most commonly occur at the sacrum, skull base, and spine. The gold standard treatment for these tumors is a combination of en-bloc resection and radiation therapy.

AREAS COVERED

Recent genomic studies have identified duplication of the gene brachyury as a major susceptibility mutation in familial chordomas. Studies on sporadic chordomas have identified several tumor markers, using microRNAs and Comparative Genome Hybridization. In this article, we highlight current advances in research on the molecular characterization of chordomas.

EXPERT OPINION

Scientific advances have allowed for the identification of numerous tumor markers involved in chordoma pathogenesis. In the future, chordoma cell lines will be produced that silence or over-express these tumor markers. As we increase our understanding of the mechanism of chordoma tumor proliferation, we can expect the development of targeted drug therapies.

Durable complete response to chemotherapy in an infant with a clival chordoma

Chordomas are rare bone tumors of notochord remnants that may occur anywhere within the axial skeleton. The standard of care is complete surgical removal. Proton beam irradiation is commonly used when the tumor is inaccessible or has recurred. Chemotherapy has been used in the treatment of patients at relapse but it has been generally proven ineffective. We report a 7-month-old infant with a clival chordoma who responded to combination chemotherapy consisting of cycles of vincristine/cyclophosphamide/doxorubicin alternating with etoposide/ifosfamide. She has been off chemotherapy for 2 years and is well at age 5.

Serum creatine kinase increase in patients treated with tyrosine kinase inhibitors for solid tumors

Regarding the frequency of muscular complains with the use of tyrosine kinase inhibitors (TKIs), we hypothesize that creatine kinase (CK) elevation may be more frequent than usually reported. We conducted a prospective study on patients treated with TKIs for solid tumors, to assess the incidence of CK increase on treatment. Most of the patients (105/155) had a gastrointestinal stromal tumor. Treatments were carried out with the following drugs: imatinib (87 cases); sunitinib (21 cases); HER antagonists (14 cases), other TKIs (15 cases); and imatinib-based combinations (2 cases). Myalgias were found in 50/155 patients (32%). Fifty-four patients (35%; 95%CI, 27-42%) had elevated CK. According to NCI-CTC grading, there was 49/54 (31%) grade 1 and 5/54 (3%) grade 2 (2.5 to 5 times ULN). CK elevation was more frequent with imatinib than with other TKIs (39 cases, 45% vs. 14 cases, 21%, respectively; chi-squared test: P=0.003), and CK was more likely to be abnormal in patients treated with any TKI for more than 6 months. We found increased CK in about one-third of patients under TKIs for solid tumors, including 3% of patients with CK as high as 2.5-5 times ULN.

Chordoma: current concepts, management, and future directions

Chordoma is a rare bone cancer that is aggressive, locally invasive, and has a poor prognosis. Chordomas are thought to arise from transformed remnants of notochord and have a predilection for the axial skeleton, with the most common sites being the sacrum, skull base, and spine. The gold standard treatment for chordomas of the mobile spine and sacrum is en-bloc excision with wide margins and postoperative external-beam radiation therapy. Treatment of clival chordomas is unique from other locations with an enhanced emphasis on preservation of neurological function, typified by a general paradigm of maximally safe cytoreductive surgery and advanced radiation delivery techniques. In this Review, we highlight current standards in diagnosis, clinical management, and molecular characterisation of chordomas, and discuss current research.

Review of current treatment of sacral chordoma

Chordoma is a relatively rare, locally aggressive tumor which is known to arise from embryonic remnants of the notochord and to occur exclusively along the spinal axis, with a predilection for the sacrum. Although chordoma typically presents as a single lesion, a few cases of metastasis have been reported and the prognosis of such patients may be poor. Chordomas are slowly growing tumors with insidious onset of symptoms, making early diagnosis difficult. Recent improvements in imaging have provided valuable information for early diagnosis. The optimal treatment for sacral chordoma is en bloc sacral resection with wide surgical margins. Improvement in surgical techniques has widened the opportunities to provide effective treatment. However, the effects of adjuvant treatment options are still both unclear and controversial. Substantial progress has been made in the study of molecular-targeted therapy. The authors review the current surgical and adjuvant treatment modalities, including molecular-targeted therapy, available for management of sacral chordoma.