Objectives: Although an association between meningioma and breast cancer (BC) has been postulated, clear mechanisms remain obscure. By conducting population-based analyses in women with both BC and meningioma, hypothesis-generating causal links were pursued.
Methods: Using the US SEER 18 registry (2004 to 2009), clinicopathologic and demographic characteristics from cohorts of women with only BC (n=279,821) or meningioma (n=19,570) diagnoses were compared with 412 women with both diagnoses (BC-meningioma).
Results: BC diagnosis preceded meningioma by >2 months in 48% of women; 20% had synchronous (within 2 mo) disease. Median meningioma size was 1.9 and 2.4 cm in the BC-meningioma and meningioma cohorts, respectively (P=0.0009). Among BC-meningioma patients, meningioma size was similar whether diagnosed >2 months prior, synchronously, or >2 months after BC. Meningioma was pathologically confirmed in 38% of BC-meningioma and 51% of meningioma patients. Distribution of BC histologies was comparable in patients with and without meningioma, with ductal type predominating (80% in BC-meningioma, 83% in BC). Although hormone receptor status of invasive BC was not significantly different between BC-meningioma and BC groups, the BC-meningioma cohort had fewer women with ER+/PR+ in situ disease (P=0.006). BC stage among women with meningioma was more advanced versus women with BC only.
Conclusions: Women with BC and meningioma have smaller-sized meningiomas and more advanced BCs compared with women having only 1 diagnosis. As there was no temporal relationship between size and latency between tumor diagnoses, the disparity in meningioma size between BC-meningioma and meningioma cohorts may have BC-associated biological components that warrant further study.