gms | German Medical Science

Objective: Meningiomas are mostly benign tumors that originate from the coverings of the brain and spinal cord. Cytogenetically, they reveal a normal karyotype or, typically, monosomy of chromosome 22. Progression of meningiomas is associated with a non-random pattern of secondary losses of other autosomes. Deletion of the short arm of one chromosome 1 is a decisive step to anaplastic growth in meningiomas.

Method: We calculated an oncogenetic tree model that estimates the most likely cytogenetic pathways of 661 meningioma patients in terms of accumulation of somatic chromosome changes in tumor cells. The genetic progression score (GPS) estimates the genetic status of a tumor as progression in the corresponding tumor cells along this model.

Results: In 53 patients, one or several recurrences were documented over the period of observation. This corresponds to a total rate of recurrence of 8.0% after macroscopically complete tumor extirpation. Higher GPS values were shown to be strongly correlated with tumor recurrence [p = 2.9 × 10^-7]. High-risk tumors, both in terms of histology and cytogenetics, are localized much more frequently on the brain surface than at the skull base [p = 1.2 × 10^-5 for WHO grade and p = 3.3 × 10^-12 for GPS categorization].

Conclusions: The tendency of skull base meningiomas to recur appears to depend on surgical rather than biological reasons. As a quantitative measure, the GPS allows for a more precise assessment of the prognosis of meningiomas than the established categorical cytogenetic markers.