Chordoma dedifferentiation after proton beam therapy: a case report and review of the literature

Degenerative Atypia in Clival Chordoma: Two Case Reports

In this study, we report surgical management combined with radiotherapy in two patients with typical chordoma. Different types of radiation have varied effects on chordomas when they are radiated. Classical cases display cellular atypia and fibrosis following irradiation, while necrosis and fibrosclerosis are observed after carbon ion therapy, implying that it is possible to control the tumor more effectively using carbon ion therapy with minimal side effects.

De novo Versus Secondary Dedifferentiated Chordomas: A Population-Based Analysis and Integrated Individual Participant Data Meta-Analysis

OBJECTIVE

There is a lack of data about the clinicopathological and molecular characteristics of de novo versus secondary dedifferentiated chordoma (DC). This integrated study aimed to investigate the similarities and differences in clinicopathological manifestations, prognoses, and molecular profiles of these 2 subtypes.

METHODS

We accessed the Surveillance, Epidemiology, and End Results (SEER) Program for DC cases from 1975 to 2020. Three electronic databases were also searched for additional DCs. Individual patient data of DC patients from SEER and published literature were combined in integrated analyses.

RESULTS

After excluding duplicated patients, we identified 14 and 116 DC patients from SEER and published literature, respectively. There were 74 de novo, 39 secondary, and 18 cases with unknown origin. Our results showed that de novo and secondary DCs were not statistically different in terms of age, gender, primary location, tumor size, distant metastasis at diagnosis, extent of resection, and chemotherapy receipt. There was limited available molecular data for de novo and secondary DCs, though examples TP53 mutations were found in both. In addition, the rates of tumor relapse, metastasis during follow-up, and patient mortality were also comparable between the 2 groups. In the multivariate Cox regression model, we demonstrated that gross total removal and radiotherapy use were associated with prolonged survival of DCs.

CONCLUSIONS

De novo and secondary DCs were statistically comparable in terms of patient demographics, clinical manifestations, and prognoses. Gross total excision and radiotherapy were optimal treatments associated with better outcomes of DC patients.

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.

Proton Radiotherapy to Reduce Late Complications in Childhood Head and Neck Cancers

In most childhood head and neck cancers, radiotherapy is an essential component of treatment; however, it can be associated with problematic long-term complications. Proton beam therapy is accepted as a preferred radiation modality in pediatric cancers to minimize the late radiation side effects. Given that childhood cancers are a rare and heterogeneous disease, the support for proton therapy comes from risk modeling and a limited number of cohort series. Here, we discuss the role of proton radiotherapy in pediatric head and neck cancers with a focus on reducing radiation toxicities. First, we compare the efficacy and expected toxicities in proton and photon radiotherapy for childhood cancers. Second, we review the benefit of proton radiotherapy in reducing acute and late radiation toxicities, including risks for secondary cancers, craniofacial development, vision, and cognition. Finally, we review the cost effectiveness for proton radiotherapy in pediatric head and neck cancers. This review highlights the benefits of particle radiotherapy for pediatric head and neck cancers to improve the quality of life in cancer survivors, to reduce radiation morbidities, and to maximize efficient health care use.

Magnetic Resonance Imaging during Proton Therapy Irradiation Allows for the Early Response Assessment of Pediatric Chordoma

Chordoma in pediatric patients is very rare. Proton therapy has become a gold standard in the treatment of these neoplasms, as high dose escalation can be achieved regarding the target while maximizing the sparing of the healthy tissues near the tumor. The aim of the work was to assess the evolution of morphological sequences during treatment using T1/T2-weighted magnetic resonance imaging (MRI) for the early response assessment of a classic chordoma of the skull base in a pediatric patient who had undergone surgical excision. Our results demonstrated a significant quantitative reduction in the residual nodule component adhered to the medullary bulb junction, with an almost complete recovery of normal anatomy at the end of the irradiation treatment. This was mainly shown in the T2-weighted MRI. On the other hand, the classic component of the lesion was predominantly present and located around the tooth of the axis. The occipital condyles were morphologically and dimensionally stable for the entire irradiation period. In conclusion, the application of this type of monitoring methodology, which is unusual during the administration of a proton treatment for chordoma, highlighted the unexpected early response of the disease. At the same time, it allowed the continuous assessment of the reliability of the treatment plan.

Chordoma of the sacrum and mobile spine: a narrative review

Chordoma is a notochord-derived primary tumor of the skull base and vertebral column known to affect 0.08 to 0.5 per 100,000 persons worldwide. Patients commonly present with mechanical, midline pain with or without radicular features secondary to nerve root compression. Management of these lesions has classically revolved around oncologic resection, defined by en bloc resection of the lesion with negative margins as this was found to significantly improve both local control and overall survival. With advancement in radiation modalities, namely the increased availability of focused photon therapy and proton beam radiation, high-dose (>50 Gy) neoadjuvant or adjuvant radiotherapy is also becoming a standard of care. At present chemotherapy does not appear to have a role, but ongoing investigations into the ontogeny and molecular pathophysiology of chordoma promise to identify therapeutic targets that may further alter this paradigm. In this narrative review we describe the epidemiology, histopathology, diagnosis, and treatment of chordoma.

Long-term outcomes in the treatment of pediatric skull base chordomas in the endoscopic endonasal era

OBJECTIVE

Pediatric skull base chordoma is a rare entity that is traditionally considered to display aggressive behavior with an increased risk of recurrence. There is an absence of literature examining outcomes in the pediatric population in general and using the endoscopic endonasal approach (EEA).

METHODS

The authors retrospectively reviewed all patients with skull base chordomas presenting by the age of 18 years to the Children's Hospital of Pittsburgh or the University of Pittsburgh Medical Center from 2004 to 2019. Clinical outcomes, the number and location of recurrences, and progression-free survival time were determined.

RESULTS

Twenty patients met the study criteria. The most common presenting complaints were diplopia (n = 7), headache (n = 6), and swallowing difficulty (n = 4). Three cases were incidentally discovered. Twelve patients underwent single-stage EEA alone, 2 patients had two-stage EEA, and 6 patients had combined EEA with open far-lateral or extreme-lateral approaches. Fourteen patients underwent gross-total resection (GTR), and 6 patients had near-total resection. Larger tumors were more likely to require staging or a combined approach (86% vs 7%) and were less likely to receive GTR (33% vs 86%) but had comparable recurrence and mortality rates. Five patients developed CSF leaks requiring reoperation, 2 patients developed a permanent abducens nerve palsy, 1 patient suffered an internal carotid artery injury, 1 patient developed an epidural hematoma, and 1 patient developed a subdural empyema. Four (20%) patients had recurrence during follow-up (mean radiographic follow-up 59 months and mean time to local recurrence 19 months). Two patients with recurrence underwent further resection, and 1 patient elected to stop treatment. Both patients who underwent repeat resection experienced a second recurrence, one of whom elected to stop treatment. Both patients who died had an elevated Ki-67 (p = 0.039), one of whom developed de-differentiated histology. A third patient died of progressive spinal metastases without local recurrence and is one of 2 patients who developed postoperative spinal metastases. Both patients whose tumors became de-differentiated progressed from tumors with an initial Ki-67 of 15 or greater (p = 0.035) and received prior radiotherapy to the bulk tumor (p = 0.03).

CONCLUSIONS

The majority of pediatric skull base chordomas, when managed at a specialized center with a goal of GTR, may have a better outcome than traditionally believed. Elevated Ki-67 rates may predict poor outcome and progression to de-differentiation.

Chemoradiotherapy for Unresectable INI1-negative Chordoma in a Child

The characteristics of chordomas in children are distinct from those in adults. In particular, the prognosis of patients with INI1-negative chordoma is dismal. The standard treatment for localized chordoma, complete surgical resection with a wide margin, is seldom feasible for chordomas arising at the clivus in children, mainly due to associated complications. Therefore, other treatments for unresectable chordomas in children, including chemoradiotherapy, must be explored. Here, we report a 7-year-old girl with an INI1-negative chordoma of the clivus, who responded to conventional chemotherapy plus radiotherapy. Without surgical resection, she remains alive after 1 year and 7 months of the initial diagnosis.

State-of-the-Art Imaging in Human Chordoma of the Skull Base

Purpose of Review

Chordoma are rare tumours of the axial skeleton which occur most often at the base of the skull and in the sacrum. Although chordoma are generally slow-growing lesions, the recurrence rate is high and the location makes it often difficult to treat. Both computed tomography (CT) and magnetic resonance imaging (MRI) are crucial in the initial diagnosis, treatment planning and post-treatment follow-up.

Recent Findings

Basic MRI and CT characteristics of chordoma were described in the late 1980s and early 1990s. Since then, imaging techniques have evolved with increased resolution and new molecular imaging tools are rapidly evolving. New imaging tools have been developed not only to study anatomy, but also physiologic changes and characterization of tissue and assessment of tumour biology. Recent studies show the uptake of multiple PET tracers in chordoma, which may become an important aspect in the diagnosis, follow-up and personalized therapy.

Summary

This review gives an overview of skull base chordoma histopathology, classic imaging characteristics, radiomics and state-of-the-art imaging techniques that are now emerging in diagnosis, treatment planning and disease monitoring of skull base chordoma.

Immunophenotypic features of dedifferentiated skull base chordoma: An insight into the intratumoural heterogeneity

Chordomas are rare and low-grade malignant solid tumours, despite their histologically benign appearance, that arise in the bone from embryonic notochordal vestiges of the axial skeleton, a mesoderm-derived structure that is involved in the process of neurulation and embryonic development. Chordomas occurring in the skull base tend to arise in the basiocciput along the clivus. Three major morphological variants have been described (classical, chondroid, and atypical/dedifferentiated). The pathogenesis and molecular mechanisms involved in chordoma development remain uncertain. From a pathological standpoint, the microenvironment of a chordoma is heterogeneous, showing a dual epithelial-mesenchymal differentiation. These tumours are characterised by slow modality of biologic growth, local recurrence, low incidence of metastasis rates, and cancer stem cell (CSC) phenotype. The main molecular findings are connected with brachyury immunoexpression and activation of the downstream Akt and mTOR signalling pathways. The differentiation between typical and atypical chordomas is relevant because the tumoural microenvironment and prognosis are partially different. This review provides an insight into the recent and relevant concepts and histochemical markers expressed in chordomas, with special emphasis on dedifferentiated chordomas and their prognostic implications.