Non-small Cell Lung Cancer With Central Nervous System Metastasis

This study is collecting tissue and fluid samples from patients with non-small cell lung cancer (NSCLC) that has spread to the brain or the lining around the brain (meningeal metastases). These samples are collected during brain surgeries or procedures to better understand how lung cancer behaves when it reaches the central nervous system. **You may be eligible if...** - You have non-small cell lung cancer that has spread to the brain or the fluid around the brain, confirmed by CT or MRI scans - You are scheduled for brain surgery such as tumor removal, drainage procedures, or a shunt placement **You may NOT be eligible if...** - You have non-small cell lung cancer without brain or meningeal spread - Your physical condition makes surgery unsafe Talk to your doctor to see if this trial is right for you.