Incidental findings on brain Magnetic Resonance Imaging in long-term survivors of breast cancer treated with adjuvant chemotherapy.

PURPOSE: Incidental brain findings defined as previously undetected abnormalities of potential clinical relevance that are unexpectedly discovered at brain imaging and are unrelated to the purpose of the examination are common in the general population. Because it is unclear whether the prevalence of incidental findings in breast cancer patients treated with chemotherapy is different to that in the general population, we compared the prevalence in breast cancer survivors treated with chemotherapy to that in a population-based sample of women without a history of any cancer. PATIENTS AND METHODS: Structural brain MRI (1.5T) was performed in 191 female CMF (Cyclophosphamide, Methotrexate, 5-Fluorouracil) chemotherapy-exposed breast cancer survivors. A reference group of 1590 women without a history of cancer was sampled from a population-based cohort study. All participants were aged 50 to 80 years. Five trained reviewers recorded the brain abnormalities. Two experienced neuro-radiologists reviewed the incidental findings.
RESULTS: The cancer survivors had completed chemotherapy on average 21 years before. Of the 191 subjects, 2.6% had an aneurysm and 3.7% had a meningioma. The prevalence of meningiomas and aneurysms was not different between the groups. The prevalence of pituitary macro adenomas in the breast cancer survivors (1.6%) was higher than that in the reference group (0.1%) (OR=23.7; 95% CI 2.3-245.8).
CONCLUSION: Contrary to commonly held opinions, we did not observe an increased prevalence of meningiomas in cancer survivors. Breast cancer survivors previously treated with chemotherapy are more likely to develop pituitary adenomas than persons without a history of cancer and chemotherapy treatment.