Does Meningioma Increase the Risk of Breast Cancer?
Yes, having a meningioma modestly increases the risk of developing breast cancer, with an approximately 1.5-fold elevated risk, though the absolute increase in risk is relatively small. 1, 2
Evidence for the Association
Epidemiological Data
The relationship between meningioma and breast cancer is bidirectional and supported by multiple lines of evidence:
Population-based cohort studies demonstrate that women diagnosed with meningioma have a standardized incidence ratio (SIR) of 1.54 (95% CI: 0.77-2.75) for subsequently developing breast cancer 1
Recent Mendelian randomization analysis (2025) provides causal evidence, showing breast cancer increases meningioma risk (OR = 1.213,95% CI = 1.054-1.396, p = 0.007), suggesting shared genetic susceptibility factors that work bidirectionally 2
The association is particularly elevated in women over age 50, where risks are consistently elevated across studies, though confidence intervals sometimes include 1.0 1
Biological Plausibility
The connection between these tumors is supported by hormonal mechanisms:
Both tumors express hormone receptors: Approximately 76% of meningiomas express progesterone receptors (PR) and 6% express estrogen receptors (ER) 3
In the combined tumor population, meningiomas show higher PR positivity (32.1%) than ER positivity (7.1%), while breast cancers show the reverse pattern 4
Progestin exposure is known to increase meningioma risk and is associated with PIK3CA mutations in meningiomas 3
Clinical Implications for Women Over 40
Breast Cancer Screening Recommendations
Women diagnosed with meningioma should follow standard breast cancer screening guidelines for their age group, not enhanced surveillance protocols 3:
Begin annual mammography at age 40-50 per local guidelines 3
The modest 1.5-fold increased risk does not meet the threshold (typically >20% lifetime risk) for enhanced screening with breast MRI 3
Prioritize non-ionizing imaging modalities when feasible, given theoretical concerns about radiation exposure in patients with genetic predisposition to tumors 3
Important Diagnostic Considerations
Critical pitfall to avoid: When a woman with known breast cancer develops neurological symptoms or brain lesions, do not automatically assume metastatic disease 5, 4, 6:
Meningiomas are benign tumors that can be surgically cured, unlike brain metastases 5, 6
Proper workup with skull X-rays, CT, MRI, and potentially angiography should be performed before assuming metastatic disease 5
The mean interval between diagnosis of the two tumors is approximately 4.5 years, and meningioma can occur either before or after breast cancer diagnosis 4
Reverse Scenario Monitoring
For women with breast cancer history who develop meningioma:
The risk of meningioma after invasive breast cancer diagnosis is SIR 1.64 (95% CI: 0.79-3.02) 1
HER2-positive breast cancer specifically shows stronger association with meningioma (OR = 1.203,95% CI = 1.048-1.381, p = 0.009) 2
Breast cancer is associated with increased risk of malignant meningiomas specifically (OR = 1.64,95% CI = 1.12-2.40, p = 0.011) 2
Practical Management Algorithm
For women over 40 with meningioma:
Perform standard breast cancer screening per age-appropriate guidelines (annual mammography starting age 40-50) 3
Conduct thorough breast examination at annual follow-up visits 3
Educate patients about breast self-awareness and prompt evaluation of new breast symptoms 3
Do not order enhanced surveillance (breast MRI, more frequent mammography) based solely on meningioma diagnosis 3
Consider family history and other risk factors that might independently warrant enhanced screening 3
Shared Risk Factors
The association likely reflects shared hormonal and genetic susceptibility rather than one tumor directly causing the other 1, 2: