How is Lung Cancer Detected?

Lung cancer typically develops without early symptoms, so when symptoms do occur, the cancer is often advanced. Patients may see their doctor for a persistent cough, coughing up blood, painful breathing or coughing, shortness of breath, or other symptoms. In its early stages, primary lung cancer does not usually cause symptoms. Unfortunately, most primary lung cancers are diagnosed at late stages.


Primary or metastatic lung cancer can be diagnosed a number of different ways. Often it is detected during a standard chest X-ray. CT (Computed Tomography) scans, PET-CT (Positron Emission Tomography-Computed Tomography) scans and MRIs (Magnetic Resonance Imaging) also can be used to further identify a lung tumor. A lung cancer diagnosis can be confirmed by either performing a biopsy in which a small piece of tissue is examined or by analyzing fluid to determine if it contains a protein that is specific to tumor cells. Doctors then determine the “stage,” or extent of the disease, by establishing how big the tumor is and how much it has spread.1