Meningioma recurrence rates following treatment: a systematic analysis.

Recurrence rates of meningiomas have been widely reported in the literature, but it remains challenging for clinicians to predict recurrence rate depending on treatment, patient demographics and tumor characteristics. To address these needs, we performed a systematic analysis of the literature to determine the recurrence rate ranges of meningiomas following surgery or radiation. Our search yielded 13 studies that met all criteria for inclusion, allowing us to include 1539 patients in the assessment. Recurrence rates ranged from 0.00 to 2.36 per 100-person-years for WHO grade I meningiomas; and from 7.35 to 11.46 per 100-person-years for WHO grade II meningiomas. Our findings suggest that (1) reported recurrence rates are variable and complicated by the heterogeneity of study populations; (2) as expected, WHO grade II meningiomas generally have a higher recurrence rate than WHO grade I, when controlling for time of diagnosis (by employing person-years); and (3) there is a need for more rigorous reporting of recurrence rates, WHO grade, and Simpson grading for individual patients in order to determine a robust mean of recurrence across WHO grades.