Predicting meningioma recurrence. Royal College of Radiologists Annual Undergraduate Prize in Clinical Oncology, 1999

[Cytogenetic alterations in meningioma tumors and their impact on disease outcome]

In recent years important advances have been achieved in the understanding of the genetic abnormalities present in meningioma tumors and its association with the ontogeny and progression of these tumor. Accordingly, while the presence of monosomy 22/22q-, associated with mutation of the NF2, BAM22, RRP22, GAR22, MN1, SMARCB1, CLH22 and/or LARGE genes, is associated with neoplasic transformation, other alterations such us monosomy 14, del(1p), different chromosomal abnormalities localized at 9p, 10q and 17q and complex karyotypes are frequently related to tumor progression. From the clinical point of view, currently available information about the impact of the different cytogenetic abnormalities on disease behavior and patient outcome is still scanty; nevertheless, the presence of gains of chromosome 22 in the context of a hyperdiploid karyotype, as well as del(1p) and monosomy 14 have been associated with a statistically significantly shorter recurrence-free survival, this later abnormality showing an independent prognostic value.

The cytogenetic relationship between primary and recurrent meningiomas points to the need for new treatment strategies in cases at high risk of relapse

PURPOSE

Recurrence is the major factor influencing the clinical outcome of meningioma patients although the exact relationship between primary and recurrent tumors still needs to be clarified. The aim of the present study is to analyze the cytogenetic relationship between primary and subsequent recurrent meningiomas developed within the same individual.

EXPERIMENTAL DESIGN

Multicolor interphase fluorescence in situ hybridization was done for the identification of numerical abnormalities of 12 chromosomes in single-cell suspensions from 59 tumor samples corresponding to 25 recurrent meningioma patients. In 47 of these tumors, the distribution of different tumor cell clones was also analyzed in paraffin-embedded tissue sections. In parallel, 132 nonrecurrent cases were also studied.

RESULTS

Most recurrent meningiomas showed complex cytogenetic aberrations associated with two or more tumor cell clones in the first tumor analyzed. Interestingly, in most individuals (74%), exactly the same tumor cell clones identified in the initial lesion were also detected in the subsequent recurrent tumor samples. In the recurrent tumor samples of the remaining cases (26%), we observed tumor cell clones related to those detected in the initial lesion but which had acquired one or more additional chromosome aberrations associated with either the emergence of new clones with more complex karyotypes or the disappearance of the most representative clones from the primary lesions. Multivariate analysis of prognostic factors showed that the Maillo et al. prognostic score, based on age of patient, tumor grade, and monosomy 14, together with tumor size was the best combination of independent variables for predicting tumor recurrence at diagnosis.

CONCLUSION

Overall, our results indicate that the development of recurrent meningiomas after complete tumor resection is usually due to regrowth of the primary tumor and rarely to the emergence of an unrelated meningioma, underlining the need for alternative treatment strategies in cases at high risk of relapse, particularly those with a high Maillo et al. prognostic score and larger tumors.

[Recurrent meningiomas with progressive aggressiveness and posterior extracranial extension]

Meningiomas are in most cases benign tumors. They represent about 15% of primitive intracranial tumors. Complete surgical resection achieves healing in the majority of patients. Recurrences occur in 9 to 12% in spite of that kind of surgical resection in the initial approach. This percentage rises to 40% when removing was not complete. Recurrences sometimes show histological changes into aggressiveness, and even malignization. Two cases of originally benign meningiomas with several recurrences and progressive aggressive behaviour are presented. Both cases led to extracranial extension of the lesions, even passing through synthetic dural grafts (De Bakey's Dacron Fabric-Elastic) and the Titanium mesh covering the craniectomy.