Longitudinal treatment outcomes of recurrent clival chordomas: a single-center retrospective study

OBJECTIVE The objective of this study was to clarify the detailed clinical course of recurrent clival chordoma and the outcomes of each treatment modality. METHODS A single -center retrospective analysis was conducted on patients seen for recurrent clival chordoma. The cohort was identified from those who underwent surgery, stereotactic radiosurgery, or proton therapy at the authors' institution between 1990 and 2022. RESULTS A total of 95 recurrences in 40 patients with a median (interquartile range [IQR]) follow-up of 43 (18-79) months were identified. The median (IQR) age at the time of diagnosis was 48 (36-62) years, and 55% of patients were male. Twenty-three patients were treated with surgery followed by adjuvant radiation before the first recurrence. The median (range) number of recurrences per patient was 2 (1-8), and the median (IQR) time to the first recurrence was 29 (9-51) months. The recurrences were treated with one or more of the following therapies: surgery, radiation, systemic therapy, and laser interstitial thermal therapy (LITT). Surgery was performed for 44 recurrences in 25 patients. Radiation was used to treat 42 recurrences in 28 patients. Patients with recurrences treated with surgery plus radiation had the longest progression -free survival (PFS) (median [95% CI] overall survival [OS] 120 [0-245] months, p < 0.01, log -rank test). Patients with recurrences but without prior radiation had longer PFS than those patients with prior radiation. The median (95% CI) OS after the first recurrence was 68 (54-82) months, 5 -year OS after the first recurrence was 48%, and 10 -year OS was 27%. Multivariate Cox regression analysis showed that mortality after the first recurrence was significantly associated with no adjuvant radiation (HR 0.149, 95% CI 0.038-0.59, p = 0.0067), older age at the time of the first recurrence (HR 1.04, 95% CI 1.01-1.08, p = 0.021), and total number of recurrences (p = 0.032). Seven patients received systemic therapy, and the median (95% CI) OS of these patients since initiation of systemic therapy was 31 (11-51) months. Imatinib and/or nivolumab were used in 6 patients (15%). One patient (3%) was treated with LITT for his fourth recurrence. CONCLUSIONS Despite the aggressive nature of recurrent chordoma, 14 of 29 patients (48%) survived for more than 5 years after the initial recurrence using combined therapies. Multiple treatment options may contribute to the long-term survival of patients with this intractable tumor.