Non-Small Cell Lung Cancer Staging

The majority of lung cancers are non-small cell lung cancers (NSCLC), with 85 percent of all lung cancers being NSCLC.¹Staging for NSCLC, which describes the extent of the malignancy (cancer), is done in two parts:

1. The first staging is the clinical staging, done prior to treatment using imaging tests and blood tests.
2. The second staging is called pathologic staging and is based on surgery.^2,3

Every patient's diagnosis is different

The clinical and pathologic stages are sometimes different, such as in cases where the surgery uncovers cancer in a part of the body that was not seen in imaging scans, or when surgery reveals certain areas of suspected cancer were not in fact cancerous. In some patients, lung cancer may be diagnosed, staged, and treated all in one operation. Since many patients with NSCLC don’t have surgery, the clinical stage is most often used.^2,3

What is the TNM scoring system?

The American Joint Committee on Cancer created the TNM scoring system to describe different phases of cancer growth, where:

• T = Tumor size and invasiveness into adjacent tissues
• N = Lymph node involvement
• M = Metastasis, or spread of the cancer, to distant sites^2,3

Each of these elements are given numbers, and the various combinations of the elements are then grouped into stages:

• Stage I: The tumor is small (between 2-5 cm) and no lymph nodes are involved. There are no metastases.
• Stage II: The tumor is small (between 2-7 cm), and there may be cancer in the adjacent lymph nodes. There are no metastases.
• Stage III: The tumor may be small or larger, the adjacent lymph nodes and lymph nodes on the other side of the chest, above the collarbone, or in the neck are involved. There are no metastases.
• Stage IV: Stage IV includes any size tumor and any amount of lymph node involvement. The main determinant of Stage IV is the presence of metastases elsewhere in the body.²

NSCLC survival rates by stage

Survival rates are determined based on the previous outcomes of people who survive a specific amount of time after diagnosis. In lung cancer, as in other types of cancer, experts use “five-year survival rate,” or the percentage of people who survive at least five years after diagnosis, as a marker for lung cancer prognosis (projected outcome). It is important to remember that many people live beyond this 5-year marker after diagnosis of lung cancer and these statistics do not necessarily predict what will happen for any particular individual. In addition, to determine these rates, statisticians look at the past. The statistics do not take into account how treatments are evolving and improving over time.^3,4

The stage of NSCLC lung cancer at diagnosis determines treatment options and has a large impact on the survival rate. The earlier a cancer is caught, the better chances a person has of surviving. In the earliest stages, lung cancer is localized, or contained to the lung. If lung cancer spreads to other areas of the body, it is considered regional or distant.^1,3

• Stage IA NSCLC: The five-year survival rate is about 49 percent.
• Stage IB NSCLC: The five-year survival rate is about 45 percent
• Stage IIA NSCLC: The five-year survival rate is about 30 percent.
• Stage IIB NSCLC: The five-year survival rate is about 31 percent.
• Stage IIIA NSCLC: The five-year survival rate is about 14 percent.
• Stage IIIB NSCLC: The five-year survival rate is about 5 percent
• Stage IV NSCLC: The five-year survival rate is about 1 percent. This is a difficult cancer to treat, however there are still many treatment options for patients with Stage IV NSCLC.^1,3