Understanding Your Diagnosis Lung cancer usually does not cause symptoms when it first develops, but they often become present after the tumor begins growing. A cough is the most common symptom of lung cancer. Deciding on Treatment Your treatment choices depend on your age and health and the extent of the disease. You may need surgery, chemotherapy, radiation therapy, photodynamic therapy or other treatments. Your doctor will help determine the appropriate treatment for you. Managing Side Effects Side effects during cancer treatment vary from person to person. Side effects may be mild or severe enough to interfere with daily activities. Your health care team can suggest ways to ease any side effects that you experience.