Chromosome 1p and 14q FISH analysis in clinicopathologic subsets of meningioma: Diagnostic and prognostic implications

The second most frequently reported genetic abnormalities in meningiomas af ter 22q loss are deletions of Ip and 14q. To assess the potential diagnosti c and prognostic utility of these chromosomal alterations, we studied 180 w ell-characterized meningiomas using dual-color fluorescence in situ hybridi zation (FISH) with DNA probes localized to 1p32. 1p36, 14q13. and 14q32. Ou r cohort consisted of 77 benign (grade I). 74 atypical (grade II), and 29 a naplastic (grade III) meningiomas. Benign and atypical meningiomas were fur ther stratified into subsets of recurring (despite gross total resection) v s non-recurring (at least 10 yr of follow-up) and mitotically active vs bra in invasive subsets, respectively. Losses of Ip and 14q losses were identif ied in 23% and 31% of benign, 56% and 57% of atypical, and 75% and 67% of a naplastic meningiomas, respectively (p < 0.001 for 1p: p = 0.004 for 14q). Combined 1p/14q deletions were encountered in 7% benign, 39% atypical, and 63% anaplastic meningiomas (p < 0.001). Benign non-recurring meningiomas we re less likely to harbor 149 deletions than recurring examples (17% vs 50%, p = 0.013). There was a trend for anaplastic meningiomas with 14q deletion s and atypical meningiomas with combined 1p/14q deletions to have poorer ov erall survivals, though neither reached statistical significance. We conclu de that 1p and 14q deletions are highly associated with increasing histolog ic grade and play an important role in meningioma tumor progression. Furthe rmore. 14q FISH analysis may aid in assessing recurrence risk in histologic ally benign meningiomas.