Prognostic impact of pleural effusion in EGFR‐mutant non‐small cell lung cancer patients without brain metastasis

In epidermal growth factor receptor (EGFR)‐mutant non‐small cell lung cancer (NSCLC), brain metastasis is known as a poor prognosis factor. However, prognostic factors in the patients without brain metastasis remain unclear. In this study, we aimed to clarify the differences between metastatic site and prognosis in common EGFR‐mutant NSCLC patients without brain metastasis