Non-small cell lung cancer (NSCLC) is most common type of lung cancer. About 85% to 90% of lung cancers belong to this type of lung cancer. It has three main types. But their diagnosis and treatment are nearly similar. The lung forms an important part of respiratory system. Non-small cell lung cancer can affect lungs as well as spread to other parts of body.

Types of Non-Small Cell Lung Cancer

There are various types of non-small cell lung cancer. Each type is identified with different kinds of cancer cells. They grow and spread differently. There are mainly three sub-types of this disease.

Squamous Cell Carcinoma:

 It develops in the squamous cells. This type is also known as epidermoid carcinoma. It starts in squamous cells, which are found on lining inside the airways in the lungs. They are more common in middle of the lungs, near a bronchus.


This is the most common type of non-small cell lung cancer. It starts the cells lining the alveoli and may cause production of mucus. It starts in cells that secrete substances such as mucus. It is more common in women compared to men. It is more common in younger people. It affects the outer region of the lung. It is a slow growing type of lung cancer.

Large Cell Carcinoma:

 It is also known as undifferentiated carcinoma. It starts in several types of large cells. It can affect any part of lung. It grows and spreads quickly.

There are also some uncommon types of non-small cell lung cancer, such as adenosquamous carcinoma, sarcomatoid carcinoma, pleomorphic, carcinoid tumors, salivary gland carcinoma and unclassified carcinoma.

Causes and Risk Factors of Non-Small Cell Lung Cancer

The main cause of developing non-small cell lung cancer is smoking of tobacco. There are other risk factors as well, which increases chances of developing non-small cell lung cancer. Some of the risk factors are as follows-

  • Smoking cigarettes, pipes, or cigars can increase risk of developing this disease. People, who do not smoke but have a history of smoking, may also have elevated risk of this disease.
  • Exposure to second hand smoke or smoke from someone else’s use, if inhaled could increase risk of developing non-small cell lung cancer.
  • People who have received radiation therapy to chest or breast are also more likely to develop this disease.
  • Exposure to asbestos for long periods is capable of increasing risk of this disease.
  • Inhalation of harmful gases due to high level of air pollution also increases risk of this disease.
  • Smoking marijuana may also induce growth of cancer cells.
  • Consuming drinking water with high levels of arsenic also makes one more prone to this disease.
  • Exposure to chemicals such as uranium, beryllium, vinyl chloride, nickel chromates, coal products, mustard gas, chloromethyl ethers, gasoline and diesel exhaust are also said to trigger development of this disease.
  • Exposure to certain alloys, paints, pigments, and preservatives may also increase risk of this disease.
  • Products using chloride and formaldehyde are also capable of elevating the risk of this disease.

Symptoms of Non-Small Cell Lung Cancer

It may not show any symptoms sometimes. But if any of the following symptoms occur, patients should consult their doctor and get checked for Non-Small Cell Lung Cancer.

  • Pain or discomfort in chest
  • Worsening cough
  • Shortness of breath or difficulty in breathing.
  • Wheezing.
  • Blood in sputum or cough
  • Hoarseness.
  • Loss of appetite.
  • Unexplained weight loss
  • Persistent feeling of tiredness
  • Difficulty in swallowing.
  • Swelling of face
  • Swelling of veins in neck

Diagnosis of Non-Small Cell Lung cancer

Diagnosis is done to detect the presence and stage of the disease. Diagnosis for Non-Small Cell lung Cancer is similar to small cell lung cancer. Apart from that few more tests as listed below are used for its diagnosis.

  • Lab Tests– Lab test for tissues, blood or urine are also conducted to trace presence of cancerous cells and monitoring the disease.
  • Electron Microscopy– An electron microscope is used to examine the sample of tissue collected for checking out certain changes in the cells.
  • Immunohistochemistry– In this test an antibody, dye or radioisotope is added to collected sample of cancer tissue and the sample is checked for presence of certain antigens. This is used to differentiate different types of cancer.

Treatment and Prevention of Non-Small Cell Lung Cancer