Surgical Treatment of Sacral Chordoma: En Bloc Resection with Negative Margins is a Determinant of the Long-Term Outcome.

STUDY DESIGN: Retrospective case series.

OBJECTIVE: To report the outcome of a series of patients with sacral chordoma who were surgically treated at a single center.

SUMMARY: Chordomas are low-grade malignant tumors that arise from remnants of the notochord. They are most often found in the sacrum, spine and skull-base. These tumors have a slow clinical evolution and may eventually metastasize, even after adequate treatment. Rarely, they can dedifferentiate into high-grade sarcomas. Traditionally, chordomas were considered to be resistant to chemotherapy and standard radiation therapy. However, recently, adrotherapy has been shown to be effective for local and systemic control of the disease. In this study, clinical outcomes and local and systemic recurrence were reviewed to identify prognostic factors for local and systemic control.

METHODS: Thirty-three patients with sacral chordoma (19 males, 14 females; median age 61 y, range 43-80) who were surgically treated at our institution between 1994 and 2015 were reviewed. In 24 patients, resection was performed above S2. No patients received pre-operative radiotherapy (RT). Three cases received RT (carbon ion therapy) as treatment for local recurrence. Wide (R0) surgical margins were achieved in 17 patients, marginal (R1) margins in 14 patients and intralesional (R2) margins in 2 patients.

RESULTS: At a median follow-up of 53 months (range 0-198), 19 patients were continuously disease-free, 6 were disease-free after local recurrence (5) or metastases (1), 3 were alive with disease (2 local recurrence and 1 metastasis), 4 were dead of disease (1 patient died intraoperatively) and 1 was dead of another cause. Local recurrence was observed in 9 cases (27%); all 9 were treated surgically and 3 received carbon ion therapy after surgical intralesional excision. Overall survival at 10 years was 86.6%. Local recurrence-free survival at 10 years was 51%. A statistical analysis confirmed the importance of negative surgical margins (R0) to achieve local control of the disease (p = 0.0007). High resections (above S2) were associated with lower survival and higher risk of local recurrence.

CONCLUSION: Surgical en bloc resection is the primary treatment for sacral chordoma. Carbon ion therapy is used when it is difficult to obtain wide surgical margins. Due to morbidity and the disabling sequelae of surgery, adrotherapy may be considered an alternative to high (above S2-S3) sacral chordoma resections.