RADIATION-THERAPY FOR CHORDOMAS OF THE BASE OF SKULL AND CERVICAL-SPINE - PATTERNS OF FAILURE AND OUTCOME AFTER RELAPSE

Purpose: To determine the patterns of failure and outcome following relapse of chordomas of the base of skull and cervical spine. Methods and Materials: Between November 1975 and October 1993, 204 patients were treated for chordoma of the base of skull or cervical spine, of which 63 have developed relapse. These 63 patients constitute the main focus of this study. Forty-five patients presented with base of skull and 18 with cervical spine tumors. All patients received combined proton and photon beam radiation. The median prescribed dose was 70.1 cobalt-Gray equivalent (CGE) (range 66.6-77.4). There were 25 males and 38 females, with a median age of 41 years (range 7-66). Median follow-up was 54 months (range 8-158). Results: Sixty-three of the 204 patients treated (31%) had treatment failure. Among the 63 patients who relapsed, 60 (95%) experienced local recurrence, and in 49 patients (78%), this was the only site of failure. Two of 63 patients (3%) developed regional lymph node relapse and 3 of 63 (5%) developed surgical pathway recurrence (1 left neck, 1 palate and 1 nasal cavity). Thirteen of 204 patients relapsed in distant sites, accounting for 20% (13 of 63) of all patients with recurrence in this series. The most common metastatic sites were lungs and bones presenting in 7 of 13 and 6 of 13 patients, respectively. Only 2 of 13 patients failed with isolated distant metastasis. The actuarial 3- and 5-year survival rates after local relapse (60 patients) were 44 and 5%, respectively. Following distant failure (13 patients), the 3- and 5-year survival rates were 25 and 12%, respectively. After any relapse (63 patients) the corresponding survival rates were 43 and 7%. Following local relapse, 49 of 60 patients underwent salvage therapy consisting of subtotal resection in most patients (46 of 49). The remaining 11 of 60 patients received supportive care only. Salvage therapy resulted in stable or improved status without subsequent disease progression in 7 of 49 (14%), stable or improved status with subsequent disease progression in 26 of 49 (53%), and progressive disease in 16 of 49 patients (33%). The actuarial 2- and 5-year overall survival rates following relapse for the 49 patients who underwent salvage treatment were 63 and 6%, which favorably compared to the a-year survival rate of 21% for those who received supportive care only (p = 0.001). Conclusion: Local relapse is the predominant type of treatment failure for chordomas of the base of skull and cervical spine. Salvage treatment may relieve symptoms; however, most patients will ultimately succumb to their disease. Poor long-term survival rates following relapse emphasize the importance of a combined treatment approach with experienced surgeons and radiation oncologists at the time of primary treatment. For most patients, only permanent local tumor control will offer a chance of cure.