Gliomas of the Optic Nerve: A SEER-Based Epidemiologic Study.

BACKGROUND

To determine whether patients with biopsy-confirmed optic nerve glioma differ in clinical features and outcomes from those diagnosed by neuroradiologic imaging alone.

METHODS

Retrospective comparative analysis. Pilocytic astrocytomas (PAs) and gliomas of the optic nerve were identified through ICD-O codes in the Surveillance, Epidemiology, and End Results (SEER) cancer registry from 1975 through 2017. Demographics, clinical features, and outcomes were compared according to the method of diagnosis (biopsy-confirmed and radiologic only) and by age (birth through 19 years and 20 years of age and older). Differences in proportions were tested with the chi-square test. Associations with tumor-related death were evaluated with logistic regression. Statistical significance: α < 0.01.

RESULTS

Over 42 years, 313 PAs and 720 gliomas of the optic nerve were identified. The young age distributions were similar between the 2 groups. PAs were biopsied more often than gliomas (54% vs 13.2% [ P < 0.001]). Tumor-attributable death occurred more often among PAs and gliomas that were biopsied than those that were not (7.1% vs 0.7% [ P < 0.01]; 7.4% vs 1.1% [ P < 0.01], respectively). Roughly 15% of both PAs and gliomas were diagnosed in persons 20 years and older.

CONCLUSIONS

Biopsy-confirmed cases of PA and glioma of the optic nerve were associated with more therapeutic interventions and worse outcomes compared with patients who were diagnosed radiologically. Clinical variables relevant to clinical decision-making not captured by SEER likely explain the inability to meaningfully interpret outcome from the registry database. Cancer registries should avoid coding specific histopathologic diagnoses when tissue is not obtained.