Treatment-related secondary cancer in malignant meningiomas: a population-based study

Purpose To evaluate the risk of secondary cancer especially treatment-related secondary cancer in patients with malignant meningiomas by using data from surveillance, epidemiology and end results (SEER) database. Patients and methods All patients diagnosed as malignant meningiomas were identified from SEER database (1973-2007). Standardized incidence ratios (SIRs) and excess absolute risks of those with secondary cancers were analyzed. Cumulative incidence of secondary cancer over the years after diagnosis of primary malignant meningioma was also calculated in all these patients. From patients diagnosed after 1988, each patient underwent subtotal resection (STR) with postoperative radiation therapy (RT) was identified and matched with one corresponding control receiving gross total resection (GTR) alone, with the same prognostic factors (disease extension, gender and calendar year of diagnosis). In matched-pair analysis, the incidence of treatment-related secondary cancer in brain and other nervous system and overall survival were compared between the two groups. Results From SEER database, 1,603 patients diagnosed as primary malignant meningioma were identified, 56 of which suffered from secondary cancer including two with secondary brain tumor. SIR and EAR for all secondary cancers were 0.83 and -22.44, respectively. For secondary cancers in brain and other nerves system, SIR and EAR were -2.94 and -2.54. Most of the secondary cancers had similar incidences as that of primary cancer in general population. Cumulative incidence was around 4 % at 10-year follow-up. In matched-pair analysis (STR plus RT vs. GTR alone), no patient had developed secondary cancer in brain and other nervous system in either group at 5-year follow-up; at 10-year follow-up, the only one patient developed second meningioma was found in GTR group. No significant difference was observed between the two groups in overall survival (P = 0.624). Conclusion A profile of secondary cancer in malignant meningioma after long-term follow-up is provided. Radiation therapy may be helpful in this patient population considering the trade-off between prognostic benefit and long-term side effects.