When lung cancer is in the middle and late stages, the cancer involves the posterior wall pleura, especially the mural pleura, and pulls and invades the intercostal nerves or nerve roots, it may manifest as persistent dull pain in the back.
Common symptoms of lung cancer: cough, bloody sputum, chest pain, shortness of breath. Back pain is not a common clinical manifestation of lung cancer. Many patients do not have any clinical symptoms at first, and when lung cancer continues to progress to the point where the cancer invades the pleura and involves the nerves, it can manifest as a persistent or intermittent dull pain in the back. And once this symptom appears, it is usually a mid to late stage manifestation.