Negative impact of leukoaraiosis on the incidence of brain metastases in patients with lung cancer.

The embolization of cancer cells to cerebral vessels occurs early in the multi-step metastatic process. We aimed to determine whether the presence of leukoaraiosis (LA) before treatment would predict the development of brain metastases (BM) in patients with lung cancer. Between January 2014 and June 2015, 1007 patients underwent initial (i.e., prior to any chemotherapy) or routine magnetic resonance (MR) imaging of the brain and exhibited no evidence of BM. Of these, 189 underwent repeat MR imaging; 34 of 189 patients (18%) developed new BM, whereas 155 patients did not. LA was retrospectively evaluated according to Fazekas scale on the initial screening MR images of these 189 patients. The frequency of grade 0 periventricular hyperintensity (PVH) was greater among patients with BM, compared to those without BM (p = 0.001). In a multivariate analysis, patients with adenocarcinoma (95% confidence interval [CI] 1.8-171.8) and small cell carcinoma (95% CI 1.4-172.4) respectively developed BM at 9.3- and 8.8-fold higher rates than those with squamous cell carcinoma. Patients with grade 0 PVH developed BM at a rate 3.5-, 8.6-, and 3.6-fold higher rates than those with grade 1 (95% CI 1.4-9.0), 2 (95% CI 2.4-41.9), and 3 (95% CI 1.02-15.0), respectively. Lung cancer patients with grade 0 PVH on initial MR images have a high subsequent incidence of BM. PVH is a useful method for evaluating risk of BM.