Loss of material from chromosome arm 1p during malignant progression of meningioma revealed by fluorescent in Situ hybridization

BACKGROUND Atypical and anaplastic meningiomas tend to recur and to invade adjacent brain, bone, and skin. They also can metastasize to extracranial organs such as the lung, liver, or bone, causing death. Recent reports have indicated that allelic deletion of chromosome 1p is associated with malignant progression of meningiomas. METHODS Cytogenetic analysis of 37 meningiomas was performed using double‐target fluorescent in situ hybridization (FISH) and focusing on chromosome arm 1p. The meningioma series included 17 benign meningiomas, 11 atypical meningiomas, and 9 anaplastic meningiomas. FISH was performed with pericentromeric (1q12) and subtelomeric (1p36) DNA probes to cell nuclei prepared from surgically extirpated tumor samples. RESULTS A high incidence of deletion of at least part of 1p was observed in 60.0% of atypical and 85.7% of anaplastic meningiomas. Furthermore, statistically significant differences were found with respect to these data between benign versus atypical/anaplastic meningiomas. In four cases both primary and recurrent tumors from the same patient also were investigated for allelic status. CONCLUSIONS The results of the current study support the existence of tumor suppressor gene(s) on 1p associated with malignant progression of meningioma, and suggest that detection of the allelic status of chromosome 1p by FISH may assist physicians in predicting the clinical prognosis of patients affected by this type of brain tumor. Cancer 1998;83:360‐366. © 1998 American Cancer Society. Investigation of the allelic status of 1p in both primary and recurrent tumors from the same patient supports the existence of tumor suppressor gene(s) on 1p associated with malignant progression of meningioma, and suggests that detection of the allelic status of chromosome 1p by fluorescent in situ hybridization may assist physicians in predicting the clinical prognosis of patients with this type of brain tumor.