title: Challenges of local recurrence and cure in low grade malignant tumors of the spine.
abstract: METHODS
  Systematic review and ambispective multicenter cohort study.
  
  
  OBJECTIVE
  1. To compare the effects of wide/marginal (en bloc) resection with intralesional resection on local recurrence and survival for chordomas and chondrosarcomas of the spine. 2. To determine the influence of radiation therapy in the management of chordomas and chondrosarcomas.
  
  
  BACKGROUND
  Chordomas and chondrosarcomas of the spine are prone to local recurrence and death despite being low-grade malignant tumors. No study to date has enough numbers or adequate scientific rigor to determine the influence of resection or radiation therapy on outcome.
  
  
  METHODS
  A systematic review was performed to evaluate the 2 objectives. In addition an ambispective multicenter cohort analysis of chordomas and chondrosarcomas was performed. The GRADE system of analysis integrating the results of the systematic review, the multicenter cohort study and the expert opinion of the Spine Oncology Study Group (SOSG) was used to arrive at treatment recommendations.
  
  
  RESULTS
  A total of 63 articles were included in the systematic reviews. Evidence was low quality. En bloc resection appeared to improve both local recurrence and disease free survival in Chordoma and Chondrosarcoma. Radiation therapy had a positive impact on the management of Chordoma and Chondrosarcoma with predictably low side effects. The cohort analysis showed significantly decreased local recurrence for Chordoma (P < 0.0001) and Chondrosarcoma (P < 0.0001) with en bloc resection, and significantly decreased death for both Chordoma (P = 0.0001) and Chondrosarcoma (P = 0.0015) with en bloc resection.
  
  
  CONCLUSIONS
  When wide or marginal margins (en bloc) are achieved in surgical resection of chordomas and chondrosarcomas of the spine there is a decrease in local recurrence and mortality. Therefore, en bloc resection should be undertaken for the treatment of chordomas and chondrosarcomas of the spine. Strong Recommendation, Moderate Quality Evidence.Radiation therapy of at least 60 to 65 Gy equivalents is indicated as an adjuvant treatment for chordoma and chondrosarcoma of the spine when there has been incomplete resection or an intralesional margin. Weak Recommendation, Low Quality Evidence.
authors.affiliation: Department of Orthopedic Oncology, Rizzoli Institute, Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Boriani
authors.forename: Davor
authors.initials: D
authors.lastname: Saravanja
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Peter Pal
authors.initials: PP
authors.lastname: Varga
authors.forename: Roberto
authors.initials: R
authors.lastname: Biagini
authors.forename: Charles G
authors.initials: CG
authors.lastname: Fisher
mesh_terms: D016022:Case-Control Studies; D002813:Chondrosarcoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D002817:Chordoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D018572:Disease-Free Survival; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D016017:Odds Ratio; D018714:Radiotherapy, Adjuvant; D013125:Spinal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D013131:Spine / Q000601:surgery; D016896:Treatment Outcome