Lung Cancer 2020 Nov 13
Disease flare of leptomeningeal metastases without radiological and cytological findings after the discontinuation of osimertinib.   
Rapid tumor progression occurring after the discontinuation of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy is referred to as a disease flare of non-small cell lung cancer (NSCLC). The clinicopathological features of disease flares after osimertinib discontinuation remain unclear.
We report a patient with EGFR-mutated NSCLC who experienced the progression of leptomeningeal metastases as a disease flare shortly after the discontinuation of osimertinib despite the absence of radiological or cytological findings.
If CNS symptoms develop immediately after the discontinuation of osimertinib, the possibility of a CNS disease flare should be considered even if no radiological or cytological findings are present.

Related Questions

How do you balance the risk of an EGFR flare while holding osimertinib vs the risk of pneumonitis when continuing?