What are the Stages of Non-Small Cell Lung Cancer (NSCLC)?

Non-small cell lung cancer is the most common type, and 80 percent of cases are linked to smoking. This cancer is staged 0-IV with multiple substages.

Non-small cell lung cancer (NSCLC) is a type of lung cancer that occurs when lung cells become abnormal and keep dividing and forming more cells without order or control. Non-small cell lung cancer is the most common type of lung cancer and it does not tend to grow as quickly as another type of lung cancer called small cell lung cancer.

Non-small cell lung cancer may not have symptoms early on. When symptoms do occur, they may include:

• Persistent cough 
• Coughing up blood 
• Chest pain that may be worse with deep breathing, coughing, or laughing
• Hoarseness
• Loss of appetite
• Unexplained weight loss
• Shortness of breath
• Breathing problems
• Fatigue
• Weakness
• Wheezing
• Respiratory infections such as bronchitis and pneumonia that don’t go away or recur

If lung cancer spreads (metastasizes) to other parts of the body, symptoms may include:

• Bone pain 
• Headache
• Weakness or numbness of extremities
• Dizziness
• Problems with balance 
• Seizures
• Yellowing of the skin and eyes (jaundice)
• Swollen lymph nodes 

The main cause of all lung cancers, including non-small cell lung cancer, is smoking. Smoking causes about 80% of all lung cancer deaths, as well as a number of deaths from exposure to secondhand smoke. 

Smokers exposed to radon and asbestos are at higher risk. 

In non-smokers, causes of non-small cell lung cancer include:

• Secondhand smoke
• Exposure to radon
• Air pollution
• Workplace exposure to asbestos, diesel exhaust, or other chemicals 
• Genetic changes
• Arsenic in drinking water (may be found in parts of Southeast Asia and South America)
• Previous radiation therapy to the lungs
• Personal or family history of lung cancer

Often symptoms of lung cancer do not appear until the cancer is advanced. For this reason, The American Cancer Society has lung cancer screening guidelines for people with a higher risk of getting lung cancer, such as smokers. 

The American Cancer Society recommends people who are 55 to 74 years old, are in fairly good health, are current smokers or who have quit in the past 15 years, and have smoked a certain number of cigarettes per day should receive regular lung cancer screenings. A test called a low-dose CAT scan or CT scan (LDCT) is typically used. 

If lung cancer is suspected, imaging tests may be used to diagnose it, such as:

• Chest X-ray
• Computed tomography (CT) scan
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET) scan
• Bone scan

Lab tests used to diagnose non-small cell lung cancer include:

• Sputum cytology 
• Thoracentesis 
• Tissue biopsy 
• Bronchoscopy masses
• Endobronchial ultrasound 
• Endoscopic esophageal ultrasound
• Mediastinoscopy and mediastinotomy
• Thoracoscopy
• Lung function tests
• Molecular tests for gene changes 
• Tests for certain proteins on tumor cells
• Blood tests
• Complete blood count (CBC) 
• Blood chemistry

Treatment for non-small cell lung cancer depends on the stage. 

Treatment for stage 0 non-small cell lung cancer includes:

• Surgery to remove the tumor
• Photodynamic therapy (PDT)
• Laser therapy
• Brachytherapy (internal radiation) 
• Treatment for stage I non-small cell lung cancer includes:
• Surgical removal of the lobe of the lung that has the tumor (lobectomy) or removal of a smaller piece of the lung (sleeve resection, segmentectomy, or wedge resection)
• Adjuvant chemotherapy 
• Radiation therapy
• Radiofrequency ablation (RFA) 
• Treatment for stage II non-small cell lung cancer includes:
• Surgery (lobectomy or sleeve resection) or removal of the entire lung (pneumonectomy) 
• Lymph node removal
• Chemotherapy 
• Radiation therapy

Treatment for stage IIIA non-small cell lung cancer includes:

• Surgery
• Chemotherapy 
• Radiation therapy
• Immunotherapy with pembrolizumab (Keytruda) 

Treatment for stage IIIB non-small cell lung cancer includes:

• Chemotherapy 
• Radiation therapy
• Immunotherapy with durvalumab (Imfinzi) or pembrolizumab (Keytruda)
• Taking part in clinical trials

Stage IV non-small cell lung cancers are widespread and hard to treat and cure. Any of the above modalities may be used to help patients live longer, but they will unlikely cure the disease at this stage. 

The staging for non-small cell lung cancer is based on several factors:

• T: The extent of the primary tumor (T)
• N: Has the cancer spread to nearby lymph nodes (N)
• M: Has the cancer spread (metastasized – M) to different sites

There are 5 stages for non-small cell lung cancer (NSCLC): 

• Stage 0: The tumor is localized in the top layers of cells lining the air passages, but has not spread into nearby tissues or outside the lung. Also called “in situ” cancer because the cells have not spread from where they formed.
• Stage I: The tumor is small and has not spread into any nearby lymph nodes. It is still possible to completely remove the cancer surgically. 
  • Stage IA tumors are 3 centimeters (cm) or less in size
  • Stage IB tumors are between 3 cm tp 4 cm in size
• Stage II is divided into 2 substages. In some cases, stage II tumors can be surgically removed, in other cases, additional treatment is necessary.
  • Stage IIA is a tumor between 4 cm to 5 cm in size that has not spread to the nearby lymph nodes
  • Stage IIB is a tumor 5 cm or less in size that has spread to the lymph nodes, or is more than 5 cm wide and has not spread to the lymph nodes
• Stage III is divided into 3 substages, based on the size of the tumor and which lymph nodes the cancer has spread to. Stage III cancers have spread to the lymph nodes in the center of the chest (the mediastinum), the rib cage, heart, esophagus, or trachea, but have not spread to distant parts of the body.
  • Stage IIIA tumors are larger than 7 cm
  • Stage IIIB tumors have spread to lymph nodes on the other side of the center of the chest, or lymph nodes above or behind the collar bone OR large tumors that have spread to the rib cage, heart, esophagus, or trachea with involvement of the mediastinal lymph nodes tumors. These tumors may be difficult to remove with surgery. 
  • Stage IIIC cancers cannot be removed with surgery but can often be treated with systemic therapy and radiation therapy.
• Stage IV lung cancer has spread (metastasized) to more than one area in the other lung, the fluid surrounding the lung or the heart, or distant parts of the body. Stage IV NSCLC is divided into 2 substages:
  • Stage IVA has spread within the chest and/or has spread to one area outside of the chest
  • Stage IVB has spread outside of the chest to more than one place in one organ or to more than one organ

Surgery is usually not a treatment option for most stage IIIB, IIIC, or IV lung cancers.

Life expectancy for non-small cell lung cancer is often expressed in five-year survival rates, that is, how many people will be alive five years after diagnosis. 

• The five-year survival rate for localized non-small cell lung cancer (cancer that has not spread outside the lung) is 61%.
• The five-year survival rate for regional non-small cell lung cancer (cancer has spread outside the lung to nearby structures or lymph nodes) is 35%.
• The five-year survival rate for distant non-small cell lung cancer (cancer has spread to distant parts of the body, such as the brain, bones, liver, or the other lung) is 6%.

The best way to help prevent non-small cell lung cancer is to not smoke, and to avoid secondhand smoke. 

Other ways to help reduce the risk of developing non-small cell lung cancer include:

• Avoiding exposure to radon 
• Limit or avoid exposure to asbestos, diesel exhaust, and other cancer-causing agents
• Eat a healthy, balanced diet with plenty of fruits and vegetables