Signs of lung cancer can vary from person to person. Consistent cough and shortness of breath are two of the most common signs of lung cancer. Chest pain, weight loss, and constant fatigue are also lung cancer symptoms. During stage 1, the cancer is within the lung and in stage, it starts spreading in the chest. At stage 3, cancer starts growing into larger tumors and by stage 4 of lung cancer, it spreads throughout the body.