3. Chest pain
This is sometimes the first symptom patients perceive as different and disturbing, especially if they have COPD and other respiratory diseases that cause cough and shortness of breath. Chest pain can be mild or very severe, depending on the size of the tumor and the inflammatory response it is causing. Chest pain increases during exercise or periods of intense stress. It happens because cancer activates nerve terminals in the lungs. The inflammatory cytokines are substances that also prompt a pain reaction when they are close to nerve terminals.