Little Influence of Bevacizumab in Diagnosis of Leptomeningeal Metastases in Current Study
Authors: Yang-Si Li, Ben-Yuan Jiang, Jin-Ji Yang, Hai-Yan Tu, Qing Zhou, Wei-Bang Guo, Hong-Hong Yan, Yi-Long Wu
Journal: Journal of Thoracic Oncology (2016)

It is very interesting to find out about the phenomenon that bevacizumab might lead to false-negative imaging of leptomeningeal metastases (LM).1Venniyoor A. False-negative MRI findings for leptomeningeal metastases with use of bevacizumab.J Thorac Oncol. 2017; 12: e5Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar However, the conclusion was drawn from only two patients,2Kleinschmidt-DeMasters B.K. Damek D.M. The imaging and neuropathological effects of bevacizumab (avastin) in patients with leptomeningeal carcinomatosis.J Neurooncol. 2010; 96: 375-384Crossref PubMed Scopus (25) Google Scholar and the influence of bevacizumab in diagnosis of LM needed further exploration. Brain magnetic resonance imaging (MRI) plays an important role in diagnosis of LM, but with low sensitivity and specificity. In the current study,3Li Y.S. Jiang B.Y. Yang J.J. et al.Leptomeningeal metastases in non-small cell lung cancer patients with EGFR mutations.J Thorac Oncol. 2016; 11: 1962-1969Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar we would have performed lumbar puncture for those patients complaining of neurological symptoms, and there were a total of eight patients in whom carcinoma cells were found in the cerebrospinal fluid, but with no positive presentation on brain MRI, and all eight patients had not received bevacizumab therapy before LM, indicating that the false-negative results of imaging of LM may be related more to the complex complication and the inferiority of brain MRI in identifying LM in their early stage. Tumor cells progressed to the leptomeninges and dropped into the cerebrospinal fluid, causing neurological symptoms, and an MRI scan may show only atypical neuroimaging features or even be totally clean at its early stage, as metastatic lesions have not developed yet. Furthermore, only a few patients had the opportunity to receive bevacizumab in this study and they were randomly distributed, so little impact of bevacizumab was shown in the incidence of LM with EGFR mutation in the current study.3Li Y.S. Jiang B.Y. Yang J.J. et al.Leptomeningeal metastases in non-small cell lung cancer patients with EGFR mutations.J Thorac Oncol. 2016; 11: 1962-1969Abstract Full Text Full Text PDF PubMed Scopus (159) Google Scholar We intended to demonstrate the phenomenon that LM were much more common in patients with NSCLC with EGFR mutations, but we could not come to the conclusion that EGFR mutations or tyrosine kinase inhibitor therapy could influence the development of LM. More research is needed to better understand the metastatic process in LM with or without EGFR mutations and the influence of different treatment options between the two groups. False-Negative MRI Findings for Leptomeningeal Metastases with Use of BevacizumabJournal of Thoracic OncologyVol. 12Issue 1PreviewThe phenomenon of mutation-associated site-specific metastasis, such as the metastases of erb-b2 receptor tyrosine kinase 2 gene (HER2)-amplified breast and gastroesophageal cancers to involve the brain has been reported earlier.1 The article by Li et al.2 on the tendency of EGFR-mutant adenocarcinomas to seed the leptomeninges adds to the literature on this interesting phenomenon. Li et al. do provide an extensive discussion on the etiopathology, but this pertains to metastases to brain parenchyma and does not explain the tendency toward leptomeningeal metastasis (LM), a less common phenomenon. Full-Text PDF Open Archive