Poor Prognosis and Challenging Treatment of Optic Nerve Malignant Gliomas: Literature Review and Case Report Series

Background: Malignant optic glioma of adulthood is a rare, invasive neoplasm of the anterior visual pathway. In this article, the clinical features of a case series of 3 malignant optic nerve glioblastomas (World Health Organization grade IV) are presented, and the modalities of treatment and their associated survivals are discussed through a review of the existing literature to date.

Methods: A retrospective case series study was led for 3 patients diagnosed with primary optic nerve and chiasm glioblastoma, coming from 2 referral neurosurgical centers. An electronic search was conducted on MEDLINE via PUBMED, COCHRANE, from October 1973 to April 2016. Cohort, case reports, and case series were screened for investigating treatment and overall survival (OS) of malignant optic nerve gliomas. Pooled means and 95% confidence intervals of OS for each treatment were generated.

Results: From our retrospective case series, all patients had initial visual impairment (2 women and 1 man). The histologic diagnosis was done by biopsy. The patients' mean age was 67.3 years (standard deviation [SD] 18.5). The disease was rapidly lethal for all patients: median OS was 5 months (SD: 15.1). Two patients underwent chemotherapy by single cure of temozolomide, while the third one was treated with a radiochemotherapy protocol. Due to the fact that there is no gold standard treatment as first-choice treatment, a large heterogeneity in first-choice oncologic treatment is observed. However, we did not find any significant differences for OS between World Health Organization grade III and grade IV optic gliomas.

Conclusion: Malignant optic glioma is a rare and fatal disease in adults. Despite the modalities of treatment, the treatment outcomes remain unsatisfactory. There is no significant difference in the median OS of patients with malignant optic nerve, as compared with those diagnosed with other supratentorial glioblastoma. Chemoradiotherapy with temozolomide currently remains the best treatment in terms of OS. Advances in the understanding of tumor biology have yet failed to translate into effective treatment regimens.