High-grade gliomas in patients with prior systemic malignancies

Background: The current study was conducted to characterize the impact of a prior malignancy on the diagnosis, treatment, and outcome of high-grade glioma.

Methods: A retrospective study of 21 patients with a histologic diagnosis of glioblastoma multiforme (GBM), anaplastic astrocytoma (AA), or anaplastic oligodendroglioma (AO) after a prior diagnosis of solid tumor or hematologic malignancy was conducted. Glioma histology (GBM vs. AA/AO), patient age (<or= 60 years vs. > 60 years), and extent of resection (biopsy vs. subtotal vs. complete) were evaluated for their prognostic influence.

Results: Of the 21 patients studied, 17 had GBM, 3 had AA, and 1 patient had high-grade AO. There were 25 systemic carcinomas diagnosed in 21 patients (18 solid tumors including breast carcinoma, prostate carcinoma, and melanoma and 7 hematologic malignancies). The glioma occurred within a previous radiation field in only three patients, two of whom had solid tumors and one of whom had a childhood hematologic malignancy. Surgical resection was the initial treatment for the brain tumor in 17 patients, and the majority of patients received radiation therapy and adjuvant chemotherapy. Four patients who initially were misdiagnosed as having brain metastases received whole brain radiation therapy as their initial treatment, thereby compromising optimal care. The overall median survival for all the patients in the current study was 14 months (range, 1-44 months) from the time of brain tumor diagnosis. The extent of resection was found to be the only prognostic variable that was associated with survival (P = 0.03).

Conclusions: Secondary glioma may occur in patients as a consequence of therapy for a prior malignancy, but most often represents a sporadic event. The outcome and recommended treatment are identical to those for patients with primary gliomas. Accurate diagnosis is essential; neuroimaging often is suggestive of a primary brain tumor and should initiate surgical intervention so that histopathology can be obtained early and appropriate treatment instituted.