Understanding Lung Cancer

A female doctor looking at an xray of a chest on a computer

What is Lung Cancer?

Lungs are pyramid shaped organs with a sponge-like texture that allow our bodies to breathe. Our bodies need oxygen to function and produce carbon dioxide as a waste gas that needs to be released. Lungs help facilitate the exchange of oxygen and carbon dioxide when we inhale and exhale.

Lung cancer is a type of cancer that occurs in the lungs. There are two main types: Non-Small Cell Lung Cancer (NSCLC) and Small Cell Lung Cancer (SCLC).


80-85% of cancer cases are NSCLC, which occurs predominantly among heavy smokers. NSCLC has three sub-types which have similar treatment plans and outlook.

This is a rare type of lung cancer affecting less than 4% of people. The infection starts from cells in the lungs which produce mucus and other fluids. Most people with this type of cancer are either smokers or have a history of smoking, but there are cases where the patient had no history of smoking. It is more common among women than men, and is more likely to occur in young people.

This sub-type is also detected early as it is usually found on the outer parts of the lung. Notably, if you have a sub-type of adenocarcinoma called bronchioalveolar carcinoma, you have a higher chance of recovery than other types of cancer.

Large cell carcinoma
Cancer cells can be found in any part of the lung, and are known to grow rapidly making this one of the types of cancer that is difficult to control. It has a sub-type called large cell neuroendocrine carcinoma that is similar to small cell lung cancer.

Squamous cell carcinoma
Squamous cells are flat cells found along the lining of the airways in the lungs. The squamous cell carcinoma starts inside the squamous cells. People with this sub-type usually have a history of smoking, and the cells begin in the area near the bronchus.


The second type, SCLC makes up roughly 15% of lung cancer infections and spreads faster than the other type (NSCLC). 70% of people with SCLC are already in the metastatic stage by the time it’s diagnosed. This type of cancer responds well to radiotherapy and chemotherapy.

Symptoms of Lung Cancer

NSCLC and SCLC have similar symptoms, which can include the following:

  • Recurring respiratory infections, such as pneumonia and bronchitis
  • Wheezing sound when breathing
  • Persistent cough
  • Coughing up phlegm or blood
  • Increasingly painful chest pains when you breathe deeply, laugh, or cough
  • Shortness of breath
  • Weakness and fatigue
  • Unexplained weight loss and/or loss of appetite

Metastatic Lung NSCLC

When NSCLC starts to spread it is called metastatic NSCLC. This happens when cancer cells travel in the blood or lymph system from a tumor to other parts of the body. NSCLC can be diagnosed as metastatic during the initial diagnosis or throughout treatment. In most cases, cancer does not spread immediately, but gradually in stage 3 or 4 when the cancer tumor is large and comes into contact with other organs.

The spread of cancer can happen in two forms: local and distant metastasis. Local metastasis is when the cancer cell invades other parts of the lungs that were initially free of cancer. Distant metastasis is when cancer cells travel to form secondary tumors in other organs.

Symptoms of Metastatic Lung NSCLC

In the initial stages of cancer spreading, symptoms are usually concentrated on the upper part of the body. They may include:

  • Chest pains
  • Shortness of breath
  • Chronic cough

However, as the cancer advances, the symptoms vary depending on the organ that is infected by the cancer.

  • Brain: When metastatic NSCLC spreads to the brain, symptoms include poor memory, lack of balance, the pressure inside the skull that causes headaches, blurry vision, and seizures.
  • Bones: Metastatic NSCLC is likely to affect the upper arm bones, spine, and pelvic bone. You will likely experience intense pain on the affected bone, and your bones will be prone to fracturing.
  • Liver: Lung cancer that has spread to the liver can cause malfunction, which may lead to jaundice, constantly feeling full, and swelling of the abdomen.

Diagnosis and Treatment of Lung Cancer

Once lung cancer is diagnosed, your doctor will undertake a process called staging. During this they carry out different tests to understand if the cancer has spread. The type and stage of cancer will determine the appropriate treatment approach. Standard treatment options can include:

  • Surgery to cut out the cancer tissue from the affected part of the lung
  • Chemotherapy, which will shrink or kill the cancer cells; it is administered through pills or intravenously through the blood
  • Radiation using high energy rays to kill the cancer cells
  • Targeted therapy that to stops the growth and spread of cancer

You could also sign up for clinical trials. Clinical trials are new treatment options being tested for safety and effectiveness. Visit the National Cancer Institute’s Clinical Trials page for more information.

Complementary and alternative medicines are other treatment options. Examples of complementary medicine include hypnosis, acupuncture, dietary supplements, and meditation used to complement mainstream treatment procedures. Alternative treatment options are used in place of standard treatment options, which include special diets, mega doses of vitamins, herbs, magnet therapy, and so on.

The efficacy of complementary and alternative treatment options is, in most cases, yet to be proven scientifically.

Additional Resources