Metastatic Potential of Grade I Chondrosarcoma of Bone: Results of a Multi-institutional Study.
BACKGROUND
Little is known about the metastatic potential of low-grade chondrosarcoma. This study was designed to evaluate the rate of metastasis to identify possible risk factors.


METHODS
The files of 225 patients with newly diagnosed, grade I chondrosarcoma of bone treated between 1975 and 2012 were retrospectively analyzed. Median follow-up was 80 months for survivors (range 24-445 months). Nonparametric analyses were performed with the Mann-Whitney U test. Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank test.


RESULTS
Fourteen patients developed metastases after a median of 49 months. Metastasis-free survival probability (MFS) was 95 % at 5 years and 92 % at 10 years. Post-metastasis survival probability amounted to 27 % after 5 years. Tumor size at diagnosis (P = 0.698) and surgical margin width (P = 0.514) had no influence on MFS. Patients who developed local recurrences had a significantly lower 10-year MFS than patients without recurrences (69 % vs. 99 %, P < 0.001). Patients with grade I recurrences had a significantly poorer MFS than patients without recurrences (P = 0.013) but a significantly higher MFS than patients with grade II recurrences (P = 0.006). Patients with thoracic wall tumors had a significantly lower 10-year MFS of 66 % compared with patients with tumors of the upper (100 %, P < 0.001) and lower extremity (93 %, P = 0.033).


CONCLUSIONS
The biological behavior of low-grade chondrosarcoma appears to be more consistent with the WHO definition of rarely metastasizing bone tumors, rather than the one of locally aggressive neoplasms. Thoracic wall tumors and the development of local recurrences were associated with a higher metastasis rate in this study.
Department of General Orthopedics and Tumor Orthopedics, Münster University Hospital, Münster, Germany. dimosthenis.andreou@ukmuenster.de.
Dimosthenis
http://orcid.org/0000-0002-5083-9678
D
Andreou
Department of Orthopedic Surgery, Medical University of Graz, Graz, Austria.
Magdalena M
MM
Gilg
Department of General Orthopedics and Tumor Orthopedics, Münster University Hospital, Münster, Germany.
Georg
G
Gosheger
Department of Pathology, Sarcoma Center Berlin-Brandenburg, HELIOS Klinikum Emil von Behring, Berlin, Germany.
Mathias
M
Werner
Department of General Orthopedics and Tumor Orthopedics, Münster University Hospital, Münster, Germany.
Jendrik
J
Hardes
Department of Hematology, Oncology and Palliative Care, Sarcoma Center Berlin-Brandenburg, HELIOS Klinikum Bad Saarow, Bad Saarow, Germany.
Daniel
D
Pink
Department of Orthopedic Surgery, Medical University of Graz, Graz, Austria.
Andreas
A
Leithner
Department of Orthopedic Oncology, Sarcoma Center Berlin-Brandenburg, HELIOS Klinikum Berlin-Buch, Berlin, Germany.
Per-Ulf
PU
Tunn
Department of General Orthopedics and Tumor Orthopedics, Münster University Hospital, Münster, Germany.
Arne
A
Streitbürger
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000556:secondary* / Q000601:surgery; D002648:Child; D002813:Chondrosarcoma / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult