Cerebral Microbleeds More Common in Breast Cancer Survivors

Cerebral microbleeds in breast cancer survivors may indicate cerebrovascular frailty following adjuvant chemotherapy and radiation

medwireNews: Magnetic resonance imaging (MRI) indicates that cerebral microbleeds (CMBs) are significantly more common in women who have previously received adjuvant chemotherapy and radiotherapy for breast cancer than those who did not require breast cancer treatment.

“[O]ur hypothesis is that the presence of CMBs does not relate to the overall systemic effect of cytotoxic treatment on neural tissue, but that it marks cancer therapy-related vascular frailty that could partially explain the often-reported relationship between adjuvant chemotherapy and cognitive dysfunction”, say Sanne Schagen, from the Netherlands Cancer Institute in Amsterdam, and study co-authors.

MRI revealed that the 187 patients who received six cycles of adjuvant cyclophosphamide, methotrexate and fluorouracil plus radiotherapy an average of 21.1 years earlier were significantly more likely than 374 age-matched controls to have any CMBs (22.5 vs 13.6%) and CMBs in a deep or infratentorial region (9.6 vs 4.8%). After adjustment for diastolic blood pressure, smoking status and other factors, the OR for these two outcomes was 1.83 and 2.23, respectively.

However, there was no significant association between adjuvant breast cancer treatment and the prevalence of cortical or lacunar infarctions or white matter lesion volume.

Nor did the dose of radiation to the carotid artery significantly predict the likelihood of CMBs or white matter lesion volume, the researchers say, ruling out the hypothesis that radiation-induced atherosclerosis of the carotid artery might be an underlying cause of CMBs.

Among women who received radiotherapy and chemotherapy, those with only lobar CMBs had comparable cognitive test results to patients without CMBs, the team reports in the Journal of Clinical Oncology.

However, women with deep or infratentorial CMBs (with or without lobar CMBs) had significantly poorer performance on tests of processing speed and immediate verbal memory than those without CMBs, although their recognition of verbally presented words was better than that of controls.

“Because the presence of CMBs is a predictor of cerebrovascular diseases such as first-ever symptomatic intracranial hemorrhage and infarction and bleeding after ischemic stroke, it is important to monitor [breast cancer survivors exposed to adjuvant radiotherapy and chemotherapy] with an elevated vascular risk profile for stroke”, the team writes.

“Hopefully, our first results of an elevated prevalence of CMBs after adjuvant treatment for breast cancer encourage the scientific community to further investigate the occurrence of this unwanted outcome and to explore preventive strategies.”

Reference

Koppelmans V, Vernooij M, Boogerd W, et al. Prevalence of cerebral small-vessel disease in long-term breast cancer survivors exposed to both radiotherapy and chemotherapy. J Clin Oncol; Advance online publication 5 January 2015. doi: 10.1200/JCO.2014.56.8345

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