Intravital Microscopy in Human Solid Tumors

This study is using a specialized microscope (called intravital microscopy — a technique that can image living tissue at a cellular level in real time) during surgery to observe how cancer cells behave and interact with the surrounding environment in human solid tumors. **You may be eligible if...** - You are 18 years or older - You have a tumor that can be seen directly and needs to be surgically removed - Your tumor is one of these types: stomach, pancreatic, liver/bile duct, colorectal, sarcoma, brain, or breast cancer (including cancer in the armpit lymph nodes) - Your tumor can be primary (original site) or metastatic (spread from elsewhere) - You are in generally good health - You do not have an allergy to fluorescein (a dye used during the procedure, confirmed by a skin prick test) **You may NOT be eligible if...** - You are allergic to fluorescein based on the skin test - Your tumor is not accessible during surgery using this technique - Your health status is too poor to safely undergo surgery Talk to your doctor to see if this trial is right for you.