Efficacy of EGFR-TKI for malignant pleural effusion in lung adenocarcinoma patients

This study retrospectively investigated the effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) on long-term outcome of lung adenocarcinoma patients with malignant pleural effusion (MPE). We identified 52 patients with lung adenocarcinoma harboring activating EGFR gene mutation who had symptomatic MPE at initial diagnosis and received EGFR-TKI as firstline treatment from Taipei Medical University Hospital (Taipei, Taiwan) database. Pleural progression-free survival (PPFS) was defined as the time from administration of EGFRTKI to the first observation of pleural progression requiring therapeutic thoracentesis or death from any cause. The median duration of follow-up was 14.9 months (range 1.0-72.0 months). The overall pleural objective response rate was 94%, and the median tumor progression free survival and median PPFS was 10.2 (95% CI 7.1-12.8 months) and 13.1 months (95% CI 10.2-15.3 months), respectively. The difference in PPFS between EGFR exon 19 deletion (n = 23) and L858R mutation (n =29) groups was not statistically significant (p = 0.651). Thirty-six patients (69%) remain pleural progression-free during the whole disease course. EGFR-TKI was highly effective for malignant pleural effusion in patients with lung adenocarcinoma harboring activating EGFR mutation. It merits further prospective trial comparing EGFR-TKI alone with EGFR-TKI plus angiogenesis inhibitor in treatment of malignant pleural effusion with mutated EGFR.