By Kristen Gasnick, PT, DPT 

Published on June 15, 2023

 Medically reviewed by Susan Russell, MD

• Symptoms of Non-Small Cell Lung Cancer

Lung cancer is an abnormal growth of cells in the lungs. These abnormal cells form tumors that damage the normal functioning of the lungs. Most lung cancer cases are non-small cell lung cancer (NSCLC), which can affect different types of cells in the lungs and airways.

Without treatment, non-small cell lung cancer can spread throughout the body, causing damage to other organ systems. This article will review the types of non-small cell lung cancer, how it is diagnosed, and its treatment options.

Edwin Tan / Getty Images

Types of Non-Small Cell Lung Cancer

Non-small cell lung cancer makes up approximately 85% of all lung cancer cases. It is subdivided into three main types, depending on the type of cells that the cancer affects, as follows:¹

• Adenocarcinoma: This is the most common type of lung cancer, making up approximately 40% of all cases. It occurs in small cells located in the alveoli (air sacs) at the periphery of the lungs. Adenocarcinoma grows slowly and is more likely to be discovered before spreading to other areas of the body outside of the lungs. It can affect smokers and nonsmokers alike.

• Squamous cell carcinoma of the lungs: This type of lung cancer makes up approximately 25% to 30% of all cases. It affects the squamous cells of the bronchi, the main airways that branch from the trachea (windpipe). Squamous cell carcinoma is very common among smokers.

• Large cell carcinoma: A less common type of lung cancer, it makes up approximately 5% to 10% of cases. It affects the central portions of the lungs. It may spread into the chest, nearby lymph nodes, or other organs. It grows and spreads quickly.

Non-Small Cell Lung Cancer Symptoms

Symptoms of non-small cell lung cancer can relate to changes in your lungs, airways, and other body systems. Sometimes non-small cell lung cancer does not produce any noticeable signs and symptoms.

When asymptomatic, lung cancer may be detected through a chest X-ray if you have one done in diagnosing other conditions.¹ For people at high risk (based on their age and smoking history), low-dose computed tomography (LDCT) imaging is now recommended for screening for lung cancer.²

Early Signs

Early signs of non-small cell lung cancer, if present, often include shortness of breath and a cough that does not go away. The growth of cancer cells within the lungs and airways affects your ability to breathe, making it difficult to get air in and out of the lungs effectively. This can also result in:³

• Chest pain

• Wheezing

• Hoarse voice

• Coughing up mucus and/or blood

Symptoms After Spread

As lung cancer spreads to other parts of the body, symptoms start to involve your entire body. You may experience such systemic symptoms as:³

• Loss of appetite

• Weight loss

• Fatigue

Non-Small Cell vs. Small Cell Lung Cancer

The two main types of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer. The main differences between the two are the size of the cancer cells when examined under a microscope.

As the names suggest, small cell lung cancer results from smaller cancer cells than non-small cell lung cancer. Small cell lung cancer tends to grow and spread more quickly, but non-small cell lung cancer is much more common.⁴

 Small Cell vs. Non-Small Cell Lung Cancer: What’s the Difference?

What Causes Non-Small Cell Lung Cancer?

Anyone can develop non-small cell lung cancer, but it is much more likely to occur in smokers.³ Smoking significantly damages the lungs, causing inflammatory changes that can increase the risk of cancer cell growth.

Exposure to secondhand smoke, air pollution, radiation, toxic chemicals, dust, and fumes can also increase the risk of developing non-small cell lung cancer.³

Sometimes, lung cancer has a genetic link in which gene mutations that cause lung cancer can be passed down through generations. If you have a family history of lung cancer, you may be at an increased risk of developing lung cancer.³

How Is Non-Small Cell Lung Cancer Diagnosed? 

Non-small cell lung cancer is diagnosed through testing that examines the structure and function of your lungs. Diagnosis involves a variety of tests and procedures, which include:³

• Chest X-ray: Produces an image of your chest and lungs to check for abnormal growths and structural changes

• Computed tomography (CT) scan: A series of X-rays used to produce a three-dimensional (3D) image of the chest from different angles to check for cancer growth

• Sputum cytology: A procedure to examine a sample of mucus and other fluids coughed up from the lungs (sputum) for cancer cells

• Thoracentesis: A procedure that removes fluid from the space between the lungs and chest wall lining to test the fluid for cancer cells

• Biopsy: A procedure that removes fluid or tissue from the lungs or nearby lymph nodes to test for cancer cells

• Bronchoscopy: A procedure in which an instrument is inserted through the nose or mouth into the airways to examine the inside of the airways in the lungs and remove tissue samples for cancer cell testing

• Thoracoscopy: A surgical procedure in which an incision is made between the ribs to insert an instrument to examine the chest and lungs and remove tissue samples for cancer cell testing

• Mediastinoscopy: A surgical procedure in which an incision is made at the top of the sternum (breastbone) through which an instrument is inserted to examine the chest and lungs and remove tissue samples for cancer cell testing

• Lab tests: Can check for genetic markers to see if you are at risk for lung cancer and assess your overall health

Non-Small Cell Lung Cancer Stages

As lung cancer continues to grow, it can progress through different stages. A higher stage of non-small cell lung cancer indicates that the cancer is worsening and spreading to other parts of the body. The stage of non-small cell lung cancer will influence what type of treatment is most appropriate.

The stages of non-small cell lung cancer include:³

• Occult (hidden) stage: Cancer cells are found in samples taken from the airways or from sputum, but no cancer growths can be seen in the body through imaging tests.

• Stage 0: Abnormal cells that may become cancer are found in the lining of the airways.

• Stage 1: Cancer has formed in the lungs but has not spread to the lymph nodes, forming a tumor 3 centimeters (cm) or smaller (stage 1A) or between 3 and 4 cm in size (stage 1B). Stage 1B may involve the spreading of the tumor to the bronchus and/or inner lining of the lung. 

• Stage 2: Cancer in the lungs has formed a tumor between 4 and 5 cm in size (stage 2A) that involves spreading of the tumor to the bronchus and/or inner lining of the lung, or a tumor between 5 and 7 cm in size has spread to the lymph nodes on the same side of the body. 

• Stage 3: Cancer in the lungs has formed a tumor between 5 and 7 cm in size that has spread to lymph nodes on the same side of the body near the trachea or aorta that may also spread to the bronchus and/or inner lining of the lung (stage 3A), or a tumor of any size has spread to lymph nodes on the opposite side of the body with possible spread to the heart, esophagus, or diaphragm (stage 3B). Stage 3B may also involve a tumor of any size that has spread to the lymph nodes on either side of the body and one or more separate tumors in another lobe of the lung.

• Stage 4: Cancer has formed multiple lung tumors and spread to one organ (stage 4A) or multiple organs (stage 4B) not located near the lung, such as the brain, liver, kidney, bones, or adrenal glands.

Non-Small Cell Lung Cancer Treatment

Treatment for non-small cell lung cancer will depend on the stage of cancer at diagnosis.

Surgery

Surgical removal of a cancerous tumor from the lung is the first treatment option for early stages of non-small cell lung cancer, including stages 1 and 2 and stage 3A, when the cancer is well-isolated with minimal spread to other areas of the body.⁵

For all other stages of non-small cell lung cancer, the tumor has spread too much to other areas, making surgery ineffective at removing enough of the cancer.⁵

Radiation Therapy

Radiation therapy, also called radiotherapy, involves exposing the areas of the body with cancer cells to targeted high-energy radiation beams. Radiation beams are powerful enough to damage the DNA within cancer cells to destroy them and stop them from dividing. Radiation therapy is often used together with chemotherapy to treat cancer.¹

Chemotherapy

Chemotherapy involves the use of powerful medications that kill rapidly growing cancer cells. Chemotherapy is often used for people with non-small cell lung cancer who are not eligible for immunotherapy treatment, especially if they have preexisting autoimmune conditions.⁶

Chemotherapy and radiation therapy are typically the standard treatment for people with advanced non-small cell lung cancer (stages 3 to 4). Chemotherapy is often also administered after surgery to kill off any remaining cancer cells not removed from the body surgically.⁵

Immunotherapy

Immunotherapy is a type of treatment that uses biologic medication to enhance the body’s immune system to fight off cancer. Immunotherapy medications improve the function and activity of immune system cells so that they can better target cancer cells and stop or slow their growth.¹

Targeted Therapy

Targeted therapy involves using medications that target the genes that cause cancer cells to form and divide. Approximately 10% to 30% of cases of non-small cell lung cancer are linked to mutations in the EGFR gene, while 5% or less of cases are linked to mutations in other genes, including the ALK, ROS1, RET, and BRAF V600E genes.¹

Ongoing research is geared toward developing drugs targeting these genetic mutations to stop abnormal cellular activity and decrease cancer growth and development.

Non-Small Cell Lung Cancer Prognosis

Unfortunately, lung cancer has a poor prognosis, with a one-year survival rate of less than 50% and a five-year survival rate of less than 18%. Because lung cancer is not always symptomatic, almost 40% of people with it have already developed to stage 4 at the time they are diagnosed, making treatment less effective in slowing cancer growth.⁵

Every case of lung cancer is different, however, and survival rates can vary from person to person depending on lifestyle factors and how early and aggressively treatment is administered after diagnosis.