Malignant pleural disease is highly associated with subsequent peritoneal metastasis in patients with stage IV non-small cell lung cancer independent of oncogene status

Malignant pleural disease is highly associated with peritoneal metastasis in patients with advanced NSCLC. The underlying mechanism is not clear. The presence of resistance mutations in ascitic fluid implies that poor drug penetration is unlikely to be the dominant mechanism. Despite being a late clinical finding, there were no differences in overall survival between patients who developed peritoneal metastasis and those who did not. Additional studies exploring treatment related factors in patients with malignant pleural disease that can reduce risk of peritoneal metastasis are warranted.