Tissues of the lungs that line the air passage develops cancer and it is called lung cancer. Lung cancer is a very common cause of death in both men and women.

Types of lung cancer: (1)

The two most common types of lung cancer are small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Among two types non-small cell lung cancer is more common as eighty to eighty-five percent of cases are of this type. Small cell lung cancer is less common and the percentage found is ten to fifteen only. Different types of treatments are available for both types.

Non-small cell lung cancer (NSCLC):

It is the most common type of lung cancer. Nine cases out of ten are of this type. The growing rate of this cancer is slower than other types. This cancer begins slowly and you will notice no signs and symptoms at the beginning. Signs and symptoms can be seen when cancer is in the advanced stage.

Three main types of non-small cell lung cancer are:

Adenocarcinoma of the lung:

It is one of the most common kinds of lung cancer. Thirty to forty percent of cases are of this type. Adenocarcinoma is mostly seen in breast cancer, colorectal, and prostate cancer. Glands that produce mucus in the outer region of the lungs and help in breathing got affected in adenocarcinoma. Signs and symptoms of adenocarcinoma are:

  • Coughing
  • Hoarseness
  • Loss of weight and
  • Extreme weakness

Adenocarcinoma is commonly found in former and current smokers and it usually affects the cells that are used for mucus production.

Key facts about adenocarcinoma

  • It is also very common in people who never smoked
  • Young people mostly develop this type of cancer
  • Women are more likely to develop this type as compare to men
  • It can be detected by doctors before it spreads.

Squamous cell:

It is found in the center of the lungs. The area is found where the trachea is joined with the larger bronchi or the main branches of airways. Thirty percent of cases of non-small lung cancer are of this type. This type of lung cancer is associated with smoking and smokers.

Large cell undifferentiated carcinoma:

This type of lung cancer grows and spreads more quickly than other types. This type of lung cancer can be found in any part of the lungs. Ten to fifteen percent of cases of non-small cell cancer are of this form. This type of lung cancer tends to grow and spread faster.

Key facts about large cell undifferentiated carcinoma:

  • Treatment of this type is very difficult as it grows and spreads quickly.
  • A subtype of lung cancer called LARGE CELL NEUROENDOCRINE CARCINOMA has more similarities with small cell lung cancer.

Other types:

Less common subtypes of non-small cell lung cancer include:

  • Sarcomatoid carcinoma
  • Adenosquamous carcinoma

The stages process is used by doctors to determine the severity of non-small cell lung cancer. The staging process helps in determining if cancer has spread throughout the lungs and other body parts.

The staging process of non-small cell lung cancer is classified as follows:

  • Hidden or occult phase
  • Stage 0
  • Stage 1
  • Stage 2
  • Stage 3
  • Stage 4

The number of tests is performed by the doctors do identify the stage and diagnosis. The tests included are:

  • Bone marrow aspiration
  • Biopsy
  • Scan of bone
  • Magnetic Resonance test (MRI)
  • Pulmonary function test
  • Computed tomography scan (CT-scan)
  • Positron emission tomography scan (PET-scan)

Treatment for non-small cell lung cancer:

Following treatments are given to the patients with non-small cell lung cancer:

  • Chemotherapy
  • Immunotherapy
  • Laser therapy
  • Cryotherapy
  • Photodynamic therapy
  • Radiation therapy
  • Targeted therapy
  • Surgery

Small cell lung cancer:

This type of lung cancer is also known as oat-cell. They are named because they look similar to oats when seen under a microscope. This lung cancer usually develops at the bronchi and quickly spread to other body parts. Other parts can even include lymph nodes. Small cell lung cancer is found in only twenty percent of lung cancer patients. This type of lung cancer is usually caused by tobacco smoking.

This type of lung cancer tends to grow more quickly than non-small cell lung cancer and the spreading rate to other body parts is also high than NSCLC. They respond very well to radiation and chemotherapy. It usually recurs in patients who develop it once.

SCLC is given two names based on their image under the microscope and their kind.

  • Small cell carcinoma (oat cell cancer)
  • Combined small cell carcinoma

Following tests are checked by doctors to diagnose and identify the stage of small cell lung cancer:

  • Bone scan
  • PET scan
  • CT scan
  • MRI

This type of lung cancer is very aggressive and immediate treatment is necessary. Treatment for this type of lung cancer includes:

  • Chemotherapy
  • Radiation therapy
  • Immunotherapy
  • Laser therapy
  • Surgery

Causes of lung cancer: (2)

Lung cancer can develop in any individual but more cases of lung cancer are due to smoking. Your lungs start to get damaging once you inhale the smoke once. Damage to the lungs can be repaired but continuous exposure can damage them dramatically and repair is not possible. Cells start behaving abnormally when they are damaged and chances of developing lung cancer increase. Heavy smoking is greatly linked with small cell lung cancer. With time, the risk of developing lung cancer can be reduced when you quit smoking.


Radon is naturally radioactive and when you get exposed to this gas it can cause lung cancer and it is the second leading cause of developing lung cancer. Radon can be found in buildings and it enters through the small cracks. The risk of developing lung cancer increases more when you are a smoker and get exposed to radon also. Lung Cancer can also be caused when you breathe in a hazardous environment several times. One rare type of lung cancer known as mesothelioma is caused when an individual gets exposed to Asbestos. Substances that can also cause lung cancer are:

  • Cadmium
  • Nickel
  • Arsenic
  • Some petroleum products
  • Chromium
  • Uranium

Genes can also play role in developing lung cancer. Chances are high if you smoke also.


  1. https://www.cancercenter.com/cancer-types/lung-cancer/types
  2. https://www.healthline.com/health/lung-cancer#causes