Hearing that you might have lung cancer can bring up many questions and fears. But knowing the differences between the early and late stages of lung cancer is a vital first step in understanding your path forward. The timing of when the disease is found plays a huge role in the types of treatment available and how well those treatments might work for you.
Everyone should know how lung cancer progresses, what signs and symptoms to look for at different stages, and why finding it early can lead to life-changing, effective care.
What Is Lung Cancer?
Lung cancer starts when cells in your lungs begin to grow out of control. These abnormal cells can form tumors. There are two main types of lung cancer:
- Small cell lung cancer (SCLC): This type makes up 13% of all lung cancers. It tends to grow and spread quickly.
- Non-small cell lung cancer (NSCLC): This is the most common type, making up about 87% of lung cancers. It includes several subtypes, like adenocarcinoma, squamous cell carcinoma and large cell carcinoma. NSCLC usually grows and spreads more slowly than SCLC.
The way lung cancer is treated often depends on its stage and whether it’s SCLC or NSCLC.
Understanding the Stages of Lung Cancer
Doctors use a system called cancer staging to describe how much cancer is in the body and if it has spread. Staging helps them figure out which treatments might be more effective and may offer clues about treatment outcomes.
SCLC has two stages—limited and extensive—which mean what they sound like: Limited stage means that the cancer is only on one side and is small enough to be treated using radiation in only one area. Extensive SCLC has spread either throughout one lung, to both lungs or to other areas within the body.
NSCLC lung cancer is divided into five main stages: Stage 0, Stage 1, Stage 2, Stage 3 and Stage 4.
Stage 0
Stage 0 NSCLC is very early lung cancer that is located either in the bronchus or the lung’s top lining and has not spread. It’s also known as tumor in-situ or carcinoma.
Stage 1
It’s common for people with Stage 1, an early-stage lung cancer, to have no symptoms at all. This is why it can be hard to detect.
Stage 1 cancer is only in the lung and has not spread to any lymph nodes (small bean-shaped glands that are part of your immune system). It’s usually a small tumor. It may be further classified as:
- Stage 1A: The tumor is very small, typically less than 3 centimeters (cm), about 1.2 inches, across.
- Stage 1B: The tumor is a bit larger, between 3 and 4 centimeters across, but still only in the lung.
Stage 2
Stage 2 lung cancer is still considered an early-stage cancer. At this stage, the cancer is still contained mostly within the lung or has spread to nearby lymph nodes. Stage 2 cancers may be described as:
- Stage 2A: The tumor is larger (4–5 cm) but still only in the lung OR less than 4 cm and has not spread to lymph nodes within the same lung. Stage 2A may also have spread to the main bronchus, the innermost layer of lung membrane or caused changes within the lung.
- Stage 2B: Tumors at this stage are either 5–7 cm or 5 cm or smaller with any of the following characteristics:
- The tumor is larger (5–7 cm) and hasn’t spread to the lymph nodes.
- It’s a smaller tumor that has spread to lymph nodes on the same side of the chest as the tumor.
Stage 3
Stage 3 lung cancer is considered locally advanced. The cancer has grown larger or has spread more extensively to the lymph nodes in the chest. It has not yet spread to distant parts of the body.
Sub-categories of Stage 3 cancers include:
- Stage 3A: The cancer has spread to lymph nodes on the same side of the chest as the tumor, or it has grown into nearby structures like the chest wall, diaphragm or lining around the heart.
- Stage 3B: The cancer has spread to lymph nodes further away in the chest, possibly even the lymph nodes above the collarbone, or it has grown into more critical areas like the heart, major blood vessels or windpipe.
- Stage 3C: Cancer has spread to lymph nodes on the same side of the chest as the tumor or the opposite side of the chest from the tumor. Stage 3C may involve larger tumors or more extensive local spread.
Stage 4
Stage 4 lung cancer, also known as the final stages of lung cancer, is the most advanced stage. This means the cancer has spread from the lung where it started to distant parts of the body. This spread is called metastasis.
Symptoms of Stage 4 lung cancer include those that affect the lungs, such as a cough, shortness of breath and chest pain, and significant weight loss, loss of appetite and extreme fatigue. Symptoms can also vary based on where the cancer has spread. For example:
- Bone pain, if cancer has spread to the bones
- Headaches or seizures, if it has spread to the brain
- Yellow skin or eyes (jaundice), if cancer has spread to the liver
Like other stages of lung cancer, Stage 4 lung cancer is broken down further:
- Stage 4A: The cancer has spread within the chest to the other lung, to the lining around the lung or heart (causing fluid buildup), or to a single spot not near the lung, such as the brain, liver or bones.
- Stage 4B: The cancer has spread to multiple areas in one or more distant organs.
Why Timing Matters: Early Detection and Survival Rates
The stage of lung cancer at diagnosis is one of the most important factors affecting treatment options and outcomes. Simply put, early detection significantly improves the chances of successful treatment.
When lung cancer is found in its early stages, often through screenings like a low-dose CT scan, the cancer is small and localized. This means it’s generally easier to remove surgically or treat with targeted radiation, leading to better survival rates.
Survival Rates for Early-Stage Lung Cancer
The five-year survival rate is determined by the percentage of people who are alive five years after diagnosis. For localized NSCLC lung cancer (stages 0–2), the five-year survival rate is 67%. The five-year survival rate for regional lung cancer (Stage 3) is about 40%.
Survival Rates for Stage 4 Lung Cancer
Unfortunately, once lung cancer has spread widely to other parts of the body (Stage 4), it becomes much harder to treat effectively. While treatments can help manage the disease and improve quality of life, the life expectancy of Stage 4 lung cancer is generally lower.
For NSCLC, the five-year survival rate for Stage 4 is typically around 12%. For SCLC, the five-year survival rate can be even lower.
Treatment Options by Stage
Treatment options vary greatly depending on the stage of lung cancer and the type of lung cancer (SCLC vs. NSCLC).
- Early stages (Stages 1 and 2): For NSCLC, surgery to remove the tumor and part of the lung is often the main treatment. Radiation therapy or chemotherapy might also be used. Limited-stage SCLC may be treated with surgery, chemotherapy and radiation.
- Locally advanced stages (Stage 3): Treatment often involves a combination of chemotherapy and radiation therapy, sometimes followed by surgery. Immunotherapy may also be used.
- Advanced stage (Stage 4): At this stage, the goal of treatment is often to control the cancer’s growth, manage symptoms and improve quality of life. NSCLC treatments may include chemotherapy, targeted therapy (drugs that attack specific weaknesses in cancer cells), immunotherapy (which helps your body’s immune system fight cancer) and radiation therapy to specific areas to relieve pain or other symptoms. SCLC may be treated with chemotherapy, immunotherapy and radiation therapy.
The Power of Early Detection
Understanding the stages of lung cancer and the importance of early detection is crucial. Talk to your doctor if you have symptoms or you are at high risk for lung cancer (for example, if you currently smoke or smoked in the past). They can discuss screening options, like a low-dose CT scan, which can find lung cancer in early, more treatable stages.
For people who qualify, low-dose CT lung screenings can be life-changing. Request an appointment or call 844-303-LUNG (5864) and press 1. We can see if you are eligible and help coordinate an appointment with your primary care provider.