Risk factors for lung cancer

RISK FACTORS

FOR LUNG CANCER*

Risk factors increase a person’s chances of developing lung cancer. Certain risk factors―called modifiable risk factors―are things that a person can change. Others, such as a person’s family history, are out of their control. Knowing these risks can help you or your loved one start the conversation with a doctor, and can help get the early advantage over lung cancer.

Lung cancer is one of the most preventable cancers in Canada.

Risk factors that can be controlled are responsible for about 85% of lung cancer cases ^†
Between 2020–2045, an estimated 623,500 lung cancer cases could potentially be preventable ^†

Work with your doctor to find out if there are changes you can make in your life to reduce your risk of lung cancer. Learn about the risk factors below and talk to your doctor if you think you might be at risk.

You can also talk to your loved one about making an appointment with their doctor. Together, they can find out if there are changes they can make in their life to reduce their risk of lung cancer.

Known risk factors that can be controlled*

Smoking

Tobacco smoking is the leading cause of preventable lung cancer. The longer a person smokes and the more they smoke each day, the greater their risk.

In 2015, it was estimated that 72% of all lung cancer cases diagnosed were caused by smoking

It’s never too late to quit! Quitting smoking at any age can help reduce the risk of developing lung cancer. If your loved one needs help to quit smoking, their doctor can help.

In one study, E-cigarette use, or vaping, has been shown to be increasing among youths aged 16–19 in Canada between 2017 and 2018. The long-term effects of e-cigarettes are unknown, and they may lead to cigarette smoking in the future.

Radon

Radon is a colourless, odorless, tasteless gas that is made from the natural breakdown of uranium rock and soil. The radon found outdoors does not normally cause any harm because it gets spread out in the fresh air. Radon becomes a problem when it seeps into your home through your floors or cracks in your foundation. It may reach unsafe levels in closed spaces with bad air circulation.

The risk of developing lung cancer depends on how much radon a person is exposed to and for how long. If it is determined that a home has high radon levels, there are ways to lower the amount and help reduce the risk of developing lung cancer.

After smoking, radon is the second leading cause of lung cancer in smokers and the leading cause of lung cancer in non-smokers.

Physical inactivity

Studies have shown that regularly active people are less likely to develop lung cancer. Even just 30 minutes of moderate activity a day (the kind that raises the heart rate) can reduce a person’s risk.

Exercise together! A friend or family member can be just the encouragement someone needs to get moving more. It could be walking, swimming, cycling or playing a sport you both enjoy.

Air pollution

Air pollution is harmful chemicals or particles in the air that you breathe. The type of pollutants in the air depends on the area or region that a person is in. You may find higher levels of pollutants in large cities, especially near heavily trafficked roads.

Outdoor air pollution has been linked to an increased risk of lung cancer. The more a person is in air pollution, the higher their risk.

Some research estimated that 5% of lung cancer deaths worldwide may be due to outdoor air pollution.

Being exposed to certain chemicals at work

Workers in some industries may regularly be exposed to cancer-causing chemicals that increase the risk of developing lung cancer. These toxic chemicals include asbestos, diesel engine exhaust, uranium and other radioactive agents, arsenic, nickel, cadmium, chromium compounds, crystalline silica, mustard gas, chloromethyl ethers―and several others. People who work in the following industries have the highest risk:

Construction
Transportation
Mining
Certain manufacturing sectors

Should your job (or a past job) put you at an increased risk of being around cancer-causing chemicals, make sure you’re taking care of your health, and talking to your doctor about your lung cancer risk.
If the same applies to a loved one, make sure that they are taking the necessary precautions and urge them to speak to their doctor about their lung cancer risk.

In 2020, an estimated 80% of lung cancer cases could have been attributed to certain known modifiable risk factors.^‡

Possible risk factors that can be controlled *

Second–hand smoke
Low fruit consumption
Low vegetable consumption

Possible risk factors that can’t be controlled *

Family history
Personal history of lung cancer and lung disease
Weakened immune system

Feel like your loved one is at risk or has symptoms of lung cancer? Help them get the early lead, and encourage them to talk to their doctor right away. Early detection is key.

If you think you may have symptoms of lung cancer, talk to your doctor right away to help change the odds of early detection.

Download the Early Detection Discussion Guide

Feel like your loved one is at risk or has symptoms of lung cancer? Help them get the early lead, and encourage them to talk to their doctor right away. Early detection is key.

Need help to start the conversation?

Get Ice Breakers

Please note that this list is not exhaustive and there are other risk factors for lung cancer. If you have any questions about lung cancer risk factors, be sure to ask your doctor.

†

When considering the following known and possible modifiable risk factors: tobacco, physical inactivity, residential radon, air pollution, second–hand smoke, low fruit consumption and low vegetable consumption.

‡

When considering the following known modifiable risk factors: tobacco, physical inactivity, residential radon and air pollution.