Lung Cancer
Staging
After diagnosis, your doctor will use the staging process to learn as much as possible about your type of lung cancer. Staging identifies the amount of cancer in the body and where it is located. Knowing this information allows your doctor to estimate your prognosis (outlook) and create a treatment plan that is uniquely designed for you. And, it helps you understand more about your diagnosis.
Several tests are used in the staging process:
- Physical exam.
- Blood, urine and body fluid tests.
- Imaging studies, such as positron emission tomography (PET), computed tomography (CT) of the chest and magnetic resonance imaging (MRI) of the brain.
- Tissue biopsy (done surgically) and/or liquid biopsy (performed with a needle).
- Biomarker testing.
Your doctor may use some of these test results to assign an initial stage to your cancer. This is known as the clinical stage because it is based on clinical findings, which are the signs and symptoms you are having, your health history and physical exam results. The final stage is assigned by the pathologist, a doctor who has special training in identifying diseases by studying cells and tissues under a microscope.
AJCC TNM Staging System
Non-small cell lung cancer (NSCLC) is classified according to the TNM classification and staging system developed by the American Joint Committee on Cancer (AJCC).
In the TNM system, the T stands for tumor, which indicates the primary tumor’s size and location. The N indicates whether lymph nodes have any cancer cells. This shows how far the disease has progressed. The M, for metastasis, describes if cancer has spread. A subcategory indicates the presence of tumor cells that are detected only with biomarker testing. This information is used to classify the cancer as one of four stages. View staging tables online at PatientResource.com/Lung_Cancer_Staging
Stage I cancer is in one lung and has not spread to any lymph nodes. It is further subdivided into stages IA1, IA2, IA3 and IB, based on the tumor size and how far it has spread inside one lung.
Stage II cancer has spread inside or just outside the lung and may have spread to nearby lymph nodes on the same side of the body. It also has substages IIA and IIB, based on the tumor size and whether it has spread to nearby lymph nodes and other lung structures.
Stage III cancer is found in one lung and has spread to the chest and lymph nodes farther away from the lungs. Substages IIIA, IIIB and IIIC are based on the size and number of tumors, the location and types of lymph nodes found to have cancer and exactly where the cancer has spread in the chest area.
Stage IV cancer is advanced. It has spread to the lining or the fluid around the heart or lungs or has metastasized (spread) to distant parts of the body. Substages IVA and IVB are based on the number of tumors and exactly where the cancer has spread to other organs. Having tumors in both lungs regardless of the size of the tumors is Stage IV.
Sometimes a cancer is restaged. This happens when cancer has returned or worsened. If restaging is necessary, an “r” will be placed in front of the stage. However, even if progression occurs, the stage does not always change.
Table 1. AJCC System for Classifying of Lung Cancer
Squamous cell carcinoma in situ (SCIS).
Adenocarcinoma in situ (AIS): adenocarcinoma with pure lepidic pattern (on the alveolar lining), (not more than) 3 cm in greatest dimension.
• Involves the main bronchus regardless of distance to the carina (ridge at the base of the trachea), but without involvement of the carina.
• Invades visceral pleura (membrane surrounding the lung).
• Associated with atelectasis (collapse of part of the lung) or obstructive pneumonitis (inflammation of lung tissues) that extends to the hilar region, involving part or all of the lung.
Table 2. Stages of Lung Cancer
T1a, N0, M0
T4, N2, M0
T4, N3, M0
