4 mins. read

Smoking and cancer: what’s true and what’s myth

Perci’s Lead Cancer Nurse Specialist separates the smoking myths from the facts, and explains why quitting is always a good idea

Key takeaways

  • Smoking is the leading cause of cancer worldwide and also in the UK. It’s a known cause of 15 types of cancer.
  • Not all lung cancer cases are caused by smoking; exposure to second-hand smoke, air pollution and chemicals can also cause lung cancer
  • Smoking fewer than one cigarette a day can increase your risk of dying early compared to people who have never smoked
  • To reduce cancer risk, it’s important to stop smoking as soon as possible and to stop completely

While the number of people who smoke is declining, because the overall population is increasing, more than one billion people worldwide still smoke. Half of these people will die from smoking-related causes of death. While the link between smoking and cancer risk is well known, myths about the subject still prevail. In this article, Perci’s Lead Cancer Nurse Specialist Rachel Rawson shares information about smoking and cancer we can trust, and dispels some common myths.


Smoking is the leading cause of cancer worldwide: true

Smoking is the leading cause of cancer in the UK and worldwide. Smoking is responsible for more than 8 million premature deaths globally each year.

Smoking is the leading cause of lung cancer but is also known to cause a further 14 types of cancer, including liver, pancreatic, bowel and bladder, as well as cancers of the mouth, throat, voice box and food pipe.

Only people who smoke get lung cancer: myth

An estimated 28% of lung cancer cases aren’t caused by smoking. Long-term exposure to second-hand smoke, air pollution and chemicals, such as asbestos, have also been identified as some of the contributing factors to lung cancer in non-smokers.

The most common symptoms of lung cancer are:

  • Having a new cough or a cough most of the time
  • Getting out of breath doing the things you used to do without a problem
  • Coughing up phlegm (sputum) with blood in it
  • Having an ache or pain in the chest or shoulder
  • Chest infections that keep coming back or a chest infection that doesn’t get better
  • Losing your appetite
  • Feeling tired all the time (fatigue)
  • Losing weight

It’s important to have anything different or new checked by your GP. 

There is no safe level of smoking: true

Research has found that people who smoke up to ten cigarettes a day show an increased risk of smoking-related cancers and other diseases, and people who smoke fewer than one still have an increased risk of dying early compared to people who have never smoked. 

While reducing the number of cigarettes you smoke a day is a good first step, remember the best thing you can do for your health is to stop smoking completely.

Second hand smoke, or passive smoking, also carries a risk to health. Most second hand smoke inhalation takes place in the home. To protect non-smokers you live with you should ideally stop smoking, or smoke outside. Even opening windows when smoking around non-smokers carries risk.

It’s too late to stop smoking: myth

Your cancer risk from smoking is affected by two things: 

1. How long you’ve been smoking for:

The more years you’ve been smoking for, the higher your cancer risk

2. How much you smoke:

The more cigarettes you smoke a day, the higher cancer risk

Reducing the number of cigarettes you smoke a day is a good first step, but the number of years you’ve been smoking affects your cancer risk the most. Even if you’ve smoked for years, stopping can benefit your health and reduce your cancer risk. Every year you do not smoke decreases your risk of getting serious illnesses, such as lung cancer. 

After 12 years of not smoking, your chance of developing lung cancer falls to more than half that of someone who smokes. After 15 years, your chances of getting lung cancer are almost the same as someone who has never smoked.

So if you’re thinking about stopping smoking, don’t wait. Make a plan to stop completely. Speak to your doctor or pharmacist, free local stop smoking service, or download the NHS Quit Smoking app to get support.

While we have ensured that every article is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. If you have any questions or concerns, please talk to one of our healthcare professionals or your primary healthcare team.

References:

Tobacco Atlas: https://tobaccoatlas.org/

‘Tobacco’, World Health Organisation, accessed April 2024, https://www.who.int/health-topics/tobacco

‘How does smoking cause cancer?’, Cancer Research UK, June 2023, https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/smoking-and-cancer/how-does-smoking-cause-cancer#tobaccorefs0

‘4 lung cancer myths, busted’, mdanderson.org, November 2021, https://www.mdanderson.org/cancerwise/4-lung-cancer-myths–busted.h00-159465579.html

‘Lung cancer statistics’, cancerresearchuk.org, https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/lung-cancer#heading-Three

‘Prevention: Lung cancer’, NHS, November 2022, https://www.nhs.uk/conditions/lung-cancer/prevention