Lung Cancer- Overview

Lung cancer is a cancer that begins in the lungs, usually in the cells of the air passages. It is the leading cause of cancer deaths worldwide- more than colon, breast and prostate cancers combined.

Cigarette smoking is the number one risk factor for lung cancer, linked to about 80% to 90% of lung cancer deaths. However, it can also occur in people who have never smoked.

Other risk factors include secondhand smoke, air pollution, a family history of lung cancer, and exposure to certain chemicals like arsenic and asbestos in industries.

Types of Lung Cancer

Cancer occurs in the body when normal cells multiply too rapidly without dying, leading to the formation of tumors.

The two main types of lung cancer are:

1. Small-cell lung cancer (SCLC)

2. Non-small cell lung cancer (NSCLC)

The classification is based on how they appear under a microscope. More than 80% of all lung cancer cases are NSCLC


People with lung cancer typically do not experience any symptoms until the disease is at an advanced stage. If symptoms do appear, they may resemble those of a respiratory infection, such as:

– Changes or hoarseness in a person’s voice
– Chest infections, such as bronchitis or pneumonia
– Swelling in the lymph nodes in the middle of the chest
– A persistent cough that may worsen

A person may eventually develop more severe symptoms, such as:

-Bone ache and fractures
-Spitting up blood/blood clots
-Fatigue from appetite loss and weight loss


Cancer staging describes how far the disease has spread throughout the body and how severe it is. This helps doctors to determine the best course of treatment.

The most fundamental type of staging is as follows:

Localized- in which the cancer is contained within a specific area.

Regional- in which the cancer has spread to nearby tissues or lymph nodes.

Distant- in which the cancer has spread to other parts of the body.

Survival rates

The American Cancer Society estimates that the chances of survival for 5 years or longer after a lung cancer diagnosis are as follows:


Stage Survival Rates*

Localized 64%

Regional 37%

Distant 8%

Overall 26%


Stage Survival Rates*

Localized 29%

Regional 18%

Distant 3%

Overall 7%

*The percentages represent a person’s chances of survival with lung cancer versus the chances of survival without the condition.


Regular screening is recommended for people who are at high risk of developing lung cancer.

A low-dose CT scan is used for screening, although, false positive results can occur. It is estimated that 12-14% of initial screening scans for lung cancer are false positives.

Advances in screening methods, however, have helped to reduce the rate of false positives.


A doctor will most likely recommend some diagnostic tests if a person has any symptoms that could indicate lung cancer, or if screening reveals anything unusual.

Imaging test

An X-ray, CT scan, MRI, or PET scan may reveal cancerous areas of lung tissue. These can help show changes in bones and other organs if the cancer has spread.

Tissue sampling

A biopsy may be performed to check for cancer cells. It is usually done with a fine needle or a bronchoscope.

A bronchoscope is a thin, lighted scope with a camera on the end that is inserted through the mouth or nose into the lungs. It can be used by a doctor to detect lesions and collect samples.

Other samples

Laboratory tests can also reveal whether cancer is present in the following: pleural effusion (fluid that collects around the lungs), sputum and blood.


Treatment for lung cancer is determined by a number of factors, including the type of cancer, its location and stage, the person’s overall health, and the patient’s treatment/ preference.

Lung cancer can be fatal, but new treatments mean that many people can now survive and recover from it, especially if they are diagnosed early.


Lung cancer is a potentially fatal type of cancer, but people who are diagnosed early have a better chance of survival.

Individuals who are at high risk of developing lung cancer should consider getting screened on a regular basis. This can help detect early signs of cancer and allow for treatment before it spreads.

Consult a doctor if you are concerned about having any risk factors associated with lung cancer.