Mandibular metastases in neuroblastoma: Outcomes and dental sequelae.

Background: Although metastatic involvement of bony sites including cranial bones is common in neuroblastoma (NB), mandibular metastases (MM) are uncommon, and specific outcomes have not been reported upon in the modern therapeutic era.

Methods: In this retrospective study, medical records on patients with MM from NB were reviewed. Statistical analysis was performed using the Kaplan-Meier method.

Results: Of 29 patients, nine (31%) had MM at diagnosis, whereas in 20 (69%) MM were first detected at NB relapse at a median time of 26 (6-89) months from diagnosis. Median maximal diameter of lesions was 3 (range 0.8-4.9) cm. MM were unilateral in 83% of patients, with ascending ramus (55%) and mandibular body (38%) being the two most common sites. All patients received systemic chemotherapy, and 26 (93%) patients received radiotherapy to MM. At a median follow-up of 37.3 (24.2-219.5) months, eight of nine patients with MM at diagnosis did not experience mandibular progressive disease. Eighteen of 20 patients with MM at relapse received therapeutic radiotherapy; objective responses were noted in 78%. Seventy-two percent (5/18) had not experienced relapse within the radiation field at a median of 12 (2-276) months postradiotherapy. Dental findings at follow-up after completion of NB therapy included hypodontia, hypocalcification of enamel, and trismus. Median 3-year overall survival in patients with relapsed MM was 51 ± 12% months from relapse.

Conclusion: MM when detected at diagnosis is associated with a prognosis similar to that for other skeletal metastases of NB. Radiotherapy is effective for control of MM detected both at diagnosis and relapse. Significant dental abnormalities posttherapy warrant regular dental evaluations and appropriate intervention.