Background: Skull base chondrosarcomas are difficult tumors to cure, with a predilection for
recurrence and progression over time. There are little data and no consensus on the
best management strategy when these tumors recur.
Objective: To identify the presentation and treatment-related factors which impact the progression
free survival (PFS) and disease specific survival (DSS) for recurrent chondrosarcomas,
and to identify predictors of successful salvage treatment.
Methods: A single institution retrospective review was performed on 17 patients with recurrent/progressive
chondrosarcoma over a 25-year period. Survival analysis for presentation and treatment-related
factors impacting PFS and DSS was performed using a Cox proportional hazards model.
Univariate and multivariate predictors of successful salvage treatment (defined as
PFS after salvage treatment ≥ histology specific median PSF for nonrecurrent patients)
were identified using logistic regression. Analysis was performed on first recurrence
events only, as well as all recurrence events combined.
Results: A total of 47 recurrence or progression events were analyzed from 17 patients with
a median of two events per patient (range: 1–8). The median overall PFS and DSS for
the initial recurrence was 32 (range: 3–267) and 79 (range: 3–285) months, respectively.
For first-time recurrences, failure of prior radiotherapy predicted worse PSF on multivariate
analysis (p = 0.0004), while failure of prior chemotherapy or treatment with chemotherapy were
univariate predictors of worse PFS (p = 0.04, and 0.03). Treatment with chemotherapy was a univariate predictor of worse
DSS (p = 0.003). Gross-total resection (GTR) was the only multivariate predictor of successful
salvage treatment (0.01). Across all recurrence events, histologic grade and failure
of prior radiotherapy were multivariate predictors of worse PFS (p = 0.0001 and 0.0006), while number of recurrences, pattern of recurrence, and treatment
with chemotherapy were univariate predictors (p = 0.031, 0.001, and 0.03). Multivariate predictors of DSS included histologic grade
and treatment with chemotherapy (p = 0.0001 and 0.0002), while univariate predictors also included number of recurrences,
pattern of recurrence, treatment with radiotherapy, and no surgical treatment (p = 0.04, 0.0003, 0.05, and 0.007). Histologic grade was the only multivariate predictor
of successful salvage treatment (p = 0.008).
Conclusion: Recurrence after previous radiotherapy or with higher histologic grade portends a
worse prognosis. For initial recurrences, the ability to achieve a GTR may result
in PFS comparable to nonrecurrent cases and thus surgery should be seriously considered.
While limited, these data provide insights to help guide management of these difficult
tumors when they recur.
