Development and external validation of nomograms to predict sarcoma-specific death and disease progression after surgical resection of localized high-grade conventional primary central chondrosarcoma and dedifferentiated chondrosarcoma

The Bone & Joint Journal, vol. 102-B, pp. 1752–1759

Abstract

Aims Our aim was to develop and validate nomograms that would predict the cumulative incidence of sarcoma-specific death (CISSD) and disease progression (CIDP) in patients with localized high-grade primary central and dedifferentiated chondrosarcoma. Methods The study population consisted of 391 patients from two international sarcoma centres (development cohort) who had undergone definitive surgery for a localized high-grade (histological grade II or III) conventional primary central chondrosarcoma or dedifferentiated chondrosarcoma. Disease progression captured the first event of either metastasis or local recurrence. An independent cohort of 221 patients from three additional hospitals was used for external validation. Two nomograms were internally and externally validated for discrimination (c-index) and calibration plot. Results In the development cohort, the CISSD at ten years was 32.9% (95% confidence interval (CI) 19.8% to 38.4%). Age at diagnosis, grade, and surgical margin were found to have significant effects on CISSD and CIDP in multivariate analyses. Maximum tumour diameter was also significantly associated with CISSD. In the development cohort, the c-indices for CISSD and CIDP at five years were 0.743 (95% CI 0.700 to 0.819) and 0.761 (95% CI 0.713 to 0.800), respectively. When applied to the validation cohort, the c-indices for CISSD and CIDP at five years were 0.839 (95% CI 0.763 to 0.916) and 0.749 (95% CI 0.672 to 0.825), respectively. The calibration plots for these two nomograms demonstrated good fit. Conclusion Our nomograms performed well on internal and external validation and can be used to predict CISSD and CIDP after resection of localized high-grade conventional primary central and dedifferentiated chondrosarcomas. They provide a new tool with which clinicians can assess and advise individual patients about their prognosis. Cite this article: Bone Joint J 2020;102-B(12):1752–1759.

Authors 15

1. Yusuke Tsuda

   Royal Orthopaedic Hospital · The University of Tokyo

   Affiliation as printed

   Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK

   Department of Orthopedic Surgery, University of Tokyo, Tokyo, Japan

2. Kim M. Tsoi

   Royal Orthopaedic Hospital

   Affiliation as printed

   Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK

3. Jonathan Daniel Stevenson

   Aston University · Royal Orthopaedic Hospital

   Affiliation as printed

   Aston University Medical School, Birmingham, UK

   Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK

4. Minna Laitinen

   Helsinki University Hospital

   Affiliation as printed

   Department of Orthopedics and Traumatology, Helsinki University Hospital, Helsinki, Finland

5. Peter Charles Ferguson

   University of Toronto

   Affiliation as printed

   Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Toronto, Canada

6. Jay Steven Wunder

   University of Toronto

   Affiliation as printed

   Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Toronto, Canada

7. Anthony Michael Griffin

   Mount Sinai Hospital · University of Toronto

   Affiliation as printed

   Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Toronto, Canada

   University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto, Canada

8. Michiel A. J. van de Sande Aachen Department of Orthopedic Surgery

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Orthopedic Surgery, Leiden University Medical Centre, Leiden, Netherlands

9. Veroniek M. van Praag Aachen Department of Orthopedic Surgery

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Orthopedic Surgery, Leiden University Medical Centre, Leiden, Netherlands

10. Andreas Leithner

    Medical University of Graz

    Affiliation as printed

    Department of Orthopedics and Trauma, Medical University of Graz, Graz, Austria

11. Tomohiro Fujiwara

    Royal Orthopaedic Hospital

    Affiliation as printed

    Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK

12. Hideo Yasunaga

    The University of Tokyo

    Affiliation as printed

    Department of Clinical Epidemiology and Health Economics, University of Tokyo, Tokyo, Japan

13. Hiroki Matsui

    The University of Tokyo

    Affiliation as printed

    Department of Clinical Epidemiology and Health Economics, University of Tokyo, Tokyo, Japan

14. Michael Parry

    Royal Orthopaedic Hospital

    Affiliation as printed

    Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK

15. Lee Marcus Jeys

    Royal Orthopaedic Hospital

    Affiliation as printed

    Department of Oncology, Royal Orthopaedic Hospital, Birmingham, UK