Given the dismal prognosis for patients with diffuse intrinsic pontine glioma, progression of the pontine lesion is anticipated generally within 1 year from initial radiation therapy. In most cases, biopsy at the time of clinical or radiologic progression is neither necessary nor recommended. To date, no salvage regimen has been shown to extend survival. Patients should be considered for entry into trials of novel therapeutic approaches because there are no standard agents that have demonstrated a clinically significant activity. Concomitant palliative care should be provided for these patients whether or not disease-directed therapy is administered.
The age-adjusted incidence of carcinoid tumors worldwide is approximately 2 per 100,000 persons.[1,2] The average age at diagnosis is 61.4 years. Carcinoid tumors represent about 0.5% of all newly diagnosed malignancies.[2,3]
Carcinoid tumors are rare, slow-growing tumors that originate in cells of the diffuse neuroendocrine system. They occur most frequently in tissues derived from the embryonic gut. Foregut tumors, which account for up to 25% of cases, arise...
At the time of recurrence, a complete evaluation to determine the extent of the relapse may be indicated for selected low-grade lesions. Biopsy or surgical resection should be considered for confirmation of relapse when other entities such as secondary tumor and treatment-related brain necrosis, which may be clinically indistinguishable from tumor recurrence, are in the differential. Other tests, such as positron-emission tomography, magnetic resonance spectroscopy, and single-photon emission computed tomography, have not yet been shown to be reliable in distinguishing necrosis from tumor recurrence in brain stem gliomas. Radiation-induced changes may occur a few months after the completion of radiation therapy and may mimic tumor progression. When considering the efficacy of additional treatment, care needs to be taken to separate radiation-induced change from progressive disease.
Treatment considerations at the time of recurrence or progression are dependent on prior treatment. Considerations include: further surgical resection, irradiation including 3-dimensional conformal radiation therapy, or chemotherapy. The need for surgical intervention must be individualized on the basis of the initial tumor type, the location within the brain stem, the length of time between initial treatment and the appearance of the mass lesion, and the clinical picture.
Chemotherapy with agents such as a carboplatin and vincristine may be effective in children with recurrent low-grade exophytic gliomas.[2,3]
Treatment Options Under Clinical Evaluation
Early-phase therapeutic trials may be available for selected patients. These trials may be available via Children's Oncology Group phase I institutions, the Pediatric Brain Tumor Consortium or other entities.