Primarily resected meningiomas: outcome and prognostic factors in 581 Mayo Clinic patients, 1978 through 1988.

OBJECTIVE

To establish prognostic factors for recurrence and outcome of surgical treatment, with or without postoperative radiation therapy, in patients with meningiomas.

MATERIAL AND METHODS

From 1978 through 1988, 581 patients underwent initial resection of a previously untreated primary meningioma at Mayo Clinic Rochester. In this study cohort, the outcome and prognostic factors associated with radiographic progression-free survival were analyzed.

RESULTS

Gross total resection (GTR) of the meningioma was accomplished in 80% of patients; the other 20% underwent less than GTR. Perioperative mortality within 10 days was 1.6%. Overall survival was significantly decreased from that for an age- and sex-matched cohort from the US white population. Progression-free survival at 5 and 10 years was 88% and 75%, respectively, in patients who underwent GTR and 61% and 39%, respectively, in those who underwent less than GTR. Multivariate analysis showed that age younger than 40 years, male sex, less than GTR, optic nerve involvement, and 4 or more mitotic figures per 10 high-power fields were associated with decreased progression-free survival. The 581 patients had 106 first recurrences. A trend toward improved progression-free survival was noted after first recurrence when irradiation with or without operation was used in comparison with only surgical treatment (P = 0.058).

CONCLUSION

With only operative treatment of meningioma, the 10-year recurrence rate was 25% in patients who had GTR and 61% in those who had less than GTR. These results emphasize the need for long-term follow-up and for consideration of adjuvant radiation therapy. Patients treated at the time of recurrence seem to benefit from radiation therapy with or without surgical resection. Factors associated with recurrence were (1) less than GTR, (2) involvement of the anterior visual pathway, (3) age younger than 40 years, and (4) increased mitotic index.