What are the Stages of Lung Cancer?

Stages of Lung Cancer Explained

Lung cancer is caused by the abnormal growth of damaged lung cells in uncontrollable numbers. This results in the formation of tumours, which grow in various stages and spread throughout the lungs and other parts of the body. 
For individuals at high risk, healthcare providers will suggest screening for early detection and intervention. To understand the treatment options available for lung cancer, it is first essential to have a clear idea of its various stages.  

Keep reading to learn about the stages of lung cancer, its symptoms, and its causes!

What is the TNM System in Lung Cancer Staging?

Doctors use three factors to determine the stages of lung cancer. It is also referred to as the TNM system. Here’s how this system works:

• T – Denotes the location and size of the tumour
• N – represents the involvement of lymph nodes (ball-shaped organs of the immune system present throughout your body). It is necessary to check if the lymph nodes around your lungs are affected by cancer.
• M – Refers to the metastasis status that helps identify the organs affected by cancer.
• To give additional details regarding the malignancy and help determine the phases indicated below, values are assigned to T, N, and M.

Different Stages of Lung Cancer

The TNM (Tumour, Node, and Metastasis) system is used to classify lung cancer into different stages. By using this system, there are primarily four stages of lung cancer, which are Stage 1, Stage 2, Stage 3, and Stage 4. Description of these stages is as follows:

Stage 1 Lung Cancer

If the lung cancer is in stage 1, it is small and has not spread to other distant organs or the lymph nodes. Further, stage 1 has two categorisations, 1A and 1B.

1. Stage 1A : This cancer is not wider than 3cm on its widest part and is not more than 0.5cm into deeper lung tissue. This cancer is a minimally invasive adenocarcinoma, which is a kind of non-small cell lung cancer (NSCLC).
2. Stage 1B : The width of this cancer is between 3cm and 4cm. It might grow into the main airway of the lung, grow into the membrane covering the lung, or cause the lung to collapse completely/ partly.

Stage 2 Lung Cancer

Stage 2 of lung cancer is also called NSCLC. This early-stage NSCLC indicates spread of cancer to inside the lungs in the lymph nodes or presence of more than one tumour in the same lobe of the lung. This stage of lung cancer can also be divided into two categories, which are 2A and 2B.

1. Stage 2A : Measurement of the cancer in this state is between 4cm and 5cm. It might grow into the main bronchus, or the visceral pleura, or cause the lung to collapse completely/partly. Additionally, it has not spread into different body parts and lymph nodes.
2. Stage 2B : In this stage, the size of the cancer is either 3 cm or smaller. The tumour growth in this stage is not in the membranes surrounding the lungs, different body parts, or bronchi. It spreads to the lymph nodes on the same lung and the hilar lymph nodes.

Stage 3 Lung Cancer

Stage 3 of lung cancer is an NSCLC, which is also referred to as locally advanced cancer. Apart from locations mentioned in 3B, it spreads to the chest wall, inner lining of the chest wall, nerves close to the lung, and layers of the sac that covers the heart. Here, the cancer remains in the same body part. Third-stage lung cancer has three categories:

1. Stage 3A : In this stage, the cancer is 3cm or smaller. Here, the cancer has spread to lymph nodes in the dividing region of the windpipe (carina) or the space between the lungs (mediastinum) on its cancerous side.
2. Stage 3B : The size of the affected area in this stage is the same as in stage 3A. In this, cancer has spread to the lymph nodes on the other side of the mediastinum or in the hilar lymph nodes in the opposite lung. It can also spread to the lymph nodes on either side of the body, and it can be above the collarbone or the side of the neck.
3. Stage 3C : The size of the cancer here is between 5cm and 7cm. Apart from locations mentioned in 3B, it additionally spreads to the chest wall, the inner lining of the chest wall, the nerve close to the lung, and the layers of the sac that covers the heart.

Stage 4 Lung Cancer

Also known as metastatic (advanced) lung cancer, this stage of lung cancer is the last. In this stage, cancer spreads to another lung and the fluid around the lung, heart, or distant organs. This last stage of lung cancer has two subcategories:

1. Stage 4A : Here, cancer can be of any size. In this stage, the cancer can spread to nearby organs, which are pericardium, pleura, pleural effusion, or pericardial effusion.
2. Stage 4B : The only difference between this stage and the previous stage is that cancer here can spread to distant lymph nodes and/or other organs.

At different stages of lung cancer, doctors might use various treatment techniques. It is important to know about the stage of lung cancer, as it helps in treatment by determining the location, size, and spread of the tumour.
 

What are the Symptoms of Lung Cancer?

Lung cancer often mimics symptoms of less serious illnesses, making early detection challenging. Many people remain asymptomatic until the disease advances. However, some may experience early symptoms, which can include:

●  Coughing up blood
●  Chest pain or discomfort
●  Persistent or worsening cough
●  Loss of appetite
●  Shortness of breath or trouble breathing
●  Shoulder pain
●  Swelling in the face, neck, arms, or upper chest
●  Wheezing
●  Hoarseness
●  Unexplained weight loss
●  Unexplained fatigue
●  Horner’s syndrome (drooping eyelid, small pupil, reduced sweating on one side of the face)

Additionally, early signs might include recurring coughs or pneumonia that don't resolve with treatment. Common indicators like persistent coughs, shortness of breath, and unexplained weight loss often appear in later stages, emphasizing the importance of screening for those at higher risk.

What are the Causes of Lung Cancer?

Following is a detailed overview of the causes of lung cancer:

• Lung cancer occurs when cells continue to divide uncontrollably due to mutations that disable their natural "off switch." 
• Usually, cells stop dividing or die when they have reached their limit or have too many mutations. 
• However, in the case of lung cancer, these mutated cells keep multiplying, disrupting normal cell function. 
• They can spread through the bloodstream or lymph nodes, causing damage elsewhere in the body.
•  The exact triggers for these mutations are unclear, but factors like smoking increase the risk of cellular damage, leading to lung cancer. 

This uncontrolled cell growth results in tumours that can spread and cause significant health issues. Understanding these mutations is crucial for developing effective treatments and preventive strategies.

How to Prevent Lung Cancer?

Here are some of the ways you can reduce the risks of developing lung cancer:

●  Avoid smoking
●  Stop secondhand smoking and taking other substances that can damage your lungs
●  Maintain a balanced diet that improves your lung health
●  In case of higher risks, go for screening

Thus, knowing the stages of lung cancer and adopting preventive measures can help one reduce the chances of developing this disease. However, for people with a high risk or a history of lung cancer in the family, availing a comprehensive health insurance plan can help deal with the high costs of cancer treatment.  

Check out the policies at Star Health to secure your health and finances!

Also Read:

→ What are the Stages of Ovarian Cancer

→ What Cancer is Covered by Critical Illness Insurance

→ What if I get Cancer Without Insurance

→ What is Cancer Insurance