Brain metastasis in pediatric extracranial solid tumors: survey and literature review

Objectives: Brain is a rare site of metastasis in most extracranial pediatric solid tumors. The aim of this study is to investigate the incidence, treatment, prognosis of brain metastasis in extracranial pediatric malignant tumors in a single institution and to review the literature. Methods: From September 1989 to December 2002, 1100 children less than or equal to 16 years of age with extracranial solid tumors including lymphomas were diagnosed and treated in the Division of Pediatric Oncology, Oncology Institute, Istanbul University. Patients with parenchymal metastases in the brain were assessed. Results: Sixteen (10 female, 6 male) of 1100 patients (1.45%) with extracranial solid tumors developed brain metastases. The median age of the patients was 10.5 (1-16) years. The diagnosis was sarcomas in 12 patients: 5 osteosarcomas, 4 Ewing's sarcoma family tumors, 1 rhabdomyosarcoma, 1 clear cell sarcoma of the soft tissue, 1 alveolar soft part sarcoma. Two patients had Wilms' tumor and two had germ cell tumors. Four patients (25%) had brain metastasis at diagnosis. Twelve (75%) developed brain metastasis during therapy or relapse at a median duration of 16 (1-70) months from initial diagnosis. All patients had metastases to various sites, mostly lung, at the time the brain metastases were detected. Treatment included surgery, followed by postoperative radiotherapy (RT) and chemotherapy (CT) in 1, S and RT in 1, S in 1, RT and CT in 6, RT in 1, CT in I and no treatment in 5. Only one patient with alveolar soft part sarcoma is alive with disease 20 months from diagnosis of brain metastasis. All other patients died at a median time of 2 months (2 days-6 months) from the time of brain metastasis. Conclusions: Children with metastatic cancer who develop headaches or any other neurologic symptom should be investigated for possible brain metastasis. Although, the outcome for these patients is dismal in this series and in the literature; reports of long term survival in a few cases with Wilms' tumor, osteosarcoma and alveolar soft part sarcoma who had isolated brain metastasis, suggest that a subset of patients may benefit from therapy.