Non-small cell lung cancer (NSCLC) is staged based on the TNM system, which stands for Tumor, Nodes, and Metastasis. This system helps describe the extent of the cancer and guides treatment decisions. Here are the general staging guidelines for NSCLC:

Tumor (T):

TX: Primary tumor cannot be assessed.
T0: No evidence of a primary tumor.
T1, T2, T3, T4: Describes the size and/or extent of the primary tumor.
T1: Tumor is 3 cm or smaller and limited to the lung.
T2: Tumor is larger than 3 cm or involves nearby structures.
T3: Tumor invades the chest wall, diaphragm, or other nearby structures.
T4: Tumor invades structures such as the heart, great vessels, trachea, esophagus, or spine.

Nodes (N):

NX: Regional lymph nodes cannot be assessed.
N0: No regional lymph node involvement.
N1, N2, N3: Describes the extent of regional lymph node involvement.
N1: Involvement of ipsilateral peribronchial and/or hilar lymph nodes.
N2: Involvement of ipsilateral mediastinal and/or subcarinal lymph nodes.
N3: Involvement of contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodes.

Metastasis (M):

MX: Presence of distant metastasis cannot be assessed.
M0: No distant metastasis.
M1: Distant metastasis is present.
M1a: Spread to distant non-regional lymph nodes.
M1b: Spread to distant organs or tissues.

Stages:

Stage 0: Carcinoma in situ (abnormal cells are found in the lining of a lung tumor but have not invaded nearby tissues).
Stage I: Tumor is confined to the lung and is 3 cm or smaller.
Stage II: Tumor is larger than 3 cm, or it may involve nearby structures or lymph nodes.
Stage III: Cancer has spread to regional lymph nodes or invaded nearby structures.
Stage IIIA: Cancer involves lymph nodes on the same side of the chest as the primary tumor.
Stage IIIB: Cancer has spread to lymph nodes on the opposite side of the chest, or it may involve other structures.
Stage IV: Cancer has spread to other parts of the body (distant metastasis).

The staging system helps oncologists determine the most appropriate treatment plan for each patient. Treatment options may include surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy, or a combination of these, depending on the stage and specific characteristics of the cancer. Staging also provides important information about prognosis. It's important for individuals with NSCLC to discuss their specific case and treatment options with their healthcare team.