Michelle J. Clarke, Patricia L. Zadnik, Mari L. Groves, Hormuzdiyar H. Dasenbrock, Daniel M. Sciubba, Wesley Hsu, Timothy F. Witham, Ali Bydon, Ziya L. Gokaslan and Jean-Paul Wolinsky
Traditionally, hemisacrectomy and internal hemipelvectomy procedures have required both an anterior and a posterior approach. A posterior-only approach has the potential to complete an en bloc tumor resection and spinopelvic reconstruction while reducing surgical morbidity.
The authors describe 3 cases in which en bloc resection of the hemisacrum and ilium and subsequent lumbopelvic and pelvic ring reconstruction were performed from a posterior-only approach. Two more traditional anterior and posterior staged procedures are also included for comparison.
In all 3 cases, an oncologically appropriate surgery and spinopelvic reconstruction were performed through a posterior-only approach.
The advantage of a midline posterior approach is the ability to perform a lumbosacral reconstruction, necessary in cases in which the S-1 body is iatrogenically disrupted during tumor resection.
Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
Wesley Hsu, Ahmed Mohyeldin, Sagar R. Shah, Colette M. ap Rhys, Lakesha F. Johnson, Neda I. Sedora-Roman, Thomas A. Kosztowski, Ola A. Awad, Edward F. McCarthy, David M. Loeb, Jean-Paul Wolinsky, Ziya L. Gokaslan and Alfredo Quiñones-Hinojosa
Chordoma is a malignant bone neoplasm hypothesized to arise from notochordal remnants along the length of the neuraxis. Recent genomic investigation of chordomas has identified T (Brachyury) gene duplication as a major susceptibility mutation in familial chordomas. Brachyury plays a vital role during embryonic development of the notochord and has recently been shown to regulate epithelial-to-mesenchymal transition in epithelial-derived cancers. However, current understanding of the role of this transcription factor in chordoma is limited due to the lack of availability of a fully characterized chordoma cell line expressing Brachyury. Thus, the objective of this study was to establish the first fully characterized primary chordoma cell line expressing gain of the T gene locus that readily recapitulates the original parental tumor phenotype in vitro and in vivo.
Using an intraoperatively obtained tumor sample from a 61-year-old woman with primary sacral chordoma, a chordoma cell line (JHC7, or Johns Hopkins Chordoma Line 7) was established. Molecular characterization of the primary tumor and cell line was conducted using standard immunostaining and Western blotting. Chromosomal aberrations and genomic amplification of the T gene in this cell line were determined. Using this cell line, a xenograft model was established and the histopathological analysis of the tumor was performed. Silencing of Brachyury and changes in gene expression were assessed.
The authors report, for the first time, the successful establishment of a chordoma cell line (JHC7) from a patient with pathologically confirmed sacral chordoma. This cell line readily forms tumors in immunodeficient mice that recapitulate the parental tumor phenotype with conserved histological features consistent with the parental tumor. Furthermore, it is demonstrated for the first time that silencing of Brachyury using short hairpin RNA renders the morphology of chordoma cells to a more differentiated-like state and leads to complete growth arrest and senescence with an inability to be passaged serially in vitro.
This report represents the first xenograft model of a sacral chordoma line described in the literature and the first cell line established with stable Brachyury expression. The authors propose that Brachyury is an attractive therapeutic target in chordoma and that JHC7 will serve as a clinically relevant model for the study of this disease.
Wesley Hsu, Thomas A. Kosztowski, Hasan A. Zaidi, Ziya L. Gokaslan and Jean-Paul Wolinsky
Chordomas are rare tumors that arise from the sacrum, spine, and skull base. Surgical management of these tumors can be difficult, given their locally destructive behavior and predilection for growing near delicate and critical structures. En bloc resection with negative margins can be difficult to perform without damaging adjacent structures and causing significant clinical morbidity. For chordomas of the upper cervical spine, surgical options traditionally involve transoral or submandibular approaches. The authors report the use of the image-guided, endoscopic, transcervical approach to the upper cervical spine as an alternative to traditional techniques for addressing upper cervical spine tumors, particularly for tumors where gross-total resection is not feasible.