Table of ContentsView AllTable of ContentsYears of SmokingPercentage of Smokers With CancerWhy Some Smokers Don’t Get CancerHow Smoking Causes CancerOther CancersAre E-Cigarettes Safe?Predicting RiskScreening
Table of ContentsView All
View All
Table of Contents
Years of Smoking
Percentage of Smokers With Cancer
Why Some Smokers Don’t Get Cancer
How Smoking Causes Cancer
Other Cancers
Are E-Cigarettes Safe?
Predicting Risk
Screening
It’s no surprise that smoking leads to an increased risk of cancer, especially lung cancer. However, it can be challenging to grasp just how smoking increases the risk of lung cancer. What percentage of smokers get lung cancer?
Cigarette smoking is responsible for 80% to 90% of all lung cancer cases, making it the top cause of the disease.And those who smoke are as much as 30 times more likely to get lung cancer than those who don’t.That said, some people who have never smoked a cigarette can get lung cancer, too. And some people who smoke never go on to develop lung cancer.
In this article, you will learn more about how smoking increases the risk of cancer, how many smokers will go on to develop lung cancer, and how smoking causes cancer. We will also cover whether e-cigarettes are safe, what other cancers smoking can cause, and information about lung cancer screening.
How Many Years of Smoking Causes Lung Cancer?
While it is clear that smoking increases the risk of developing lung cancer significantly, there is no clear-cut formula that says that if a person smokes for a specific length of time, they will indeed develop cancer. Up to 20% of people who develop lung cancer have never smoked a single cigarette in their life.Others might smoke for decades and die of something other than lung cancer.
That said, research has tried to quantify the risk of lung cancer in those who smoke. Here are some considerations:
What Is the Life Expectancy of Smokers?
The life expectancy of smokers can vary widely depending on factors like how long the person has been a smoker, how much they smoke, and whether they ever quit. According to the CDC, people who quit smoking can add as many as 10 years to their life expectancy.
What Percentage of Smokers Get Lung Cancer?
A study published inPreventive Medicine Reportaimed to assess these risks over 18 years, categorizing male and female smokers as “never smokers,” “former smokers,” or “current smokers.” A total of 9,623 lung cancer cases from 1995 to 2013 were included in the evaluation.
Why Do Some Smokers Never Get Lung Cancer?
Not everyone who smokes will develop lung cancer. Some studies put the number of smokers who develop lung cancer at about 15%.Other reasons people get lung cancer, including those who have never smoked, include genetic factors, ethnicity, and sex.
Some smokers who might have gone on to develop lung cancer could have a different cancer or illness first and die of that cause before lung cancer develops.
Why Lung Cancer Is Increasing in Never-Smokers
How Does Smoking Cause Cancer?
Many chemicals in cigarettes are known to cause cancer, includingformaldehyde, arsenic, andbenzene. These chemicals can cause cancer in two ways. First, they can weaken your immune system, making your body less able to kill cancer cells.
These chemicals can also change a cell’s DNA, making it more likely to abnormally replicate, leading to cancer.
It’s not just smoking that’s the problem. It is thought that roughly 7,300 Americans die from lung cancer each year due tosecondhand smoke.
What Other Cancers Can Smoking Cause?
Other cancers smoking can lead to include stomach, bladder, colon and rectum, liver, and pancreas, in addition to acute myeloid leukemia.
There has been some speculation that using e-cigarettes, also known as vaping, is less harmful than smoking cigarettes. The truth is we don’t know yet. E-cigarettes are relatively new, with the first ones developed in 2003.Early assumptions were that, compared to smoking cigarettes, e-cigarettes might reduce harm even though they still contain nicotine, the addictive substance in cigarettes, because they did not contain some of the cancer-causing agents found in cigarettes.
However, e-cigarettes contain other chemicals, and research is still determining how safe these chemicals are. The liquid contained in e-cigarettes is inhaled into the lungs as an aerosol. The chemicals inhaled include known carcinogenic chemicals like formaldehyde, acetaldehyde, and acrolein, among others.
Because the use of e-cigarettes is relatively recent, not enough time has passed to collect data to analyze how they can impact health.
Predicting Lung Cancer Risk
While it is impossible to predict who will or will not develop lung cancer, Memorial Sloan-Kettering Cancer Center has developed aLung Cancer Screening Decision Toolthat certain people can use to calculate their risk of developing lung cancer in the next ten years based on age and how long they’ve smoked.
The tool is designed for people ages 50 to 75 who have smoked between 10 and 60 cigarettes daily for a period of 25 to 55 years. It reminds you that the results are only a prediction and do not mean that you definitely will or will not develop lung cancer.
Lung Cancer Screening
In the past, there were few effective lung cancer screening tests. People had to rely on identifying theearly symptomsto spot the disease in the initial and most treatablestages.
However, since nearly half of people with lung cancer are diagnosed in theadvanced stages, general awareness of symptoms may not be enough to keep you safe.
For people who are at an increased risk of lung cancer, advancedcomputed tomography (CT) screeningcan improve the chances of early detection and, when used appropriately, reduce the risk of mortality significantly.
According to the U.S. Preventive Services Task Force, people who should have yearly CT screenings for lung cancer are those who:
The American Cancer Society has similar recommendations, except they don’t limit screening to those who have quit in the past 15 years. They recommend continuing screening as long as a person doesn’t have a health condition that limits their life expectancy or ability to get treatment if cancer is found.
Researchers performed a study that used patients' electronic health records and machine learning to indicate to clinicians which patients might benefit from lung cancer screening. This type of automation might make it easier to determine who should be screened for lung cancer in the future.
Others may benefit from screening as well. For example, anyone exposed tocancer-causing substancesin the workplace, such as radon or aerosolized benzene, may reasonably request CT screening.
If you feel that you are at an increased risk of cancer and require screening, talk to your healthcare provider.
Summary
Smoking is a major risk factor for developing lung cancer. That said, it is difficult to determine exactly which smokers will go on to develop lung cancer. And smoking also increases the risk of other cancers.
While e-cigarettes have previously been considered a safer alternative to smoking, the truth is that e-cigarettes contain some of the same carcinogenic compounds as cigarettes, and there has not been been enough data to determine how risky they are compared to cigarettes.
Screening for lung cancer is one of the best tools to reducing the incidence of death from lung cancer. If you are concerned about your lung cancer risk, speak to a healthcare provider to see if screening is appropriate for you.
How Lung Cancer Is Diagnosed
16 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute on Drug Abuse. Tobacco, Nicotine, and E-Cigarettes Research Report.What are the physical health consequences of tobacco use?Centers for Disease Control and Prevention, Division of Cancer Prevention and Control.Lung cancer risk factors.Centers for Disease Control and Prevention.Lung cancer among people who never smoked.Centers for Disease Control and Prevention.What are the risk factors for lung cancer?Centers for Disease Control and Prevention.Smoking and Cancer.Centers for Disease Control.Benefits of quitting smoking.Bruder C, Bulliard JL, Germann S, et al.Estimating lifetime and 10-year risk of lung cancer.Prev Med Rep.2018;11:125-30. doi:10.1016/j.pmedr.2018.06.010Kuśnierczyk P.Genetic differences between smokers and never-smokers with lung cancer.Front Immunol. 2023;14:1063716. doi:10.3389/fimmu.2023.1063716Dong X, Zhang L, Milholland B, et al.Accurate identification of single-nucleotide variants in whole-genome-amplified single cells.Nat Methods. 2017;14(5):491-493. doi:10.1038/nmeth.4227Centers for Disease Control and Prevention.Health effects of cigarettes: cancer.Sahu R, Shah K, Malviya R, et al.E-cigarettes and associated health risks: an update on cancer potential.Adv Respir Med. 2023;91(6):516-531. doi:10.3390/arm91060038Zappa C, Mousa SA.Non-small cell lung cancer: current treatment and future advances.Transl Lung Cancer Res. 2016;5(3):288-300. doi:10.21037/tlcr.2016.06.07Ramaswamy A.Lung cancer screening: review and 2021 update.Curr Pulmonol Rep. 2022;11(1):15-28. doi:10.1007/s13665-021-00283-1U.S. Preventive Services Task Force.Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement.JAMA.2021;325(10):962–970. doi:10.1001/jama.2021.1117Wolf AMD, Oeffinger KC, Shih TY, et al.Screening for lung cancer: 2023 guideline update from the American Cancer Society.CA Cancer J Clin. 2023;10.3322/caac.21811. doi:10.3322/caac.21811Chandran U, Reps J, Yang R, Vachani A, Maldonado F, Kalsekar I.Machine learning and real-world data to predict lung cancer risk in routine care.Cancer Epidemiol Biomarkers Prev. 2023;32(3):337-343. doi:10.1158/1055-9965.EPI-22-0873
16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Institute on Drug Abuse. Tobacco, Nicotine, and E-Cigarettes Research Report.What are the physical health consequences of tobacco use?Centers for Disease Control and Prevention, Division of Cancer Prevention and Control.Lung cancer risk factors.Centers for Disease Control and Prevention.Lung cancer among people who never smoked.Centers for Disease Control and Prevention.What are the risk factors for lung cancer?Centers for Disease Control and Prevention.Smoking and Cancer.Centers for Disease Control.Benefits of quitting smoking.Bruder C, Bulliard JL, Germann S, et al.Estimating lifetime and 10-year risk of lung cancer.Prev Med Rep.2018;11:125-30. doi:10.1016/j.pmedr.2018.06.010Kuśnierczyk P.Genetic differences between smokers and never-smokers with lung cancer.Front Immunol. 2023;14:1063716. doi:10.3389/fimmu.2023.1063716Dong X, Zhang L, Milholland B, et al.Accurate identification of single-nucleotide variants in whole-genome-amplified single cells.Nat Methods. 2017;14(5):491-493. doi:10.1038/nmeth.4227Centers for Disease Control and Prevention.Health effects of cigarettes: cancer.Sahu R, Shah K, Malviya R, et al.E-cigarettes and associated health risks: an update on cancer potential.Adv Respir Med. 2023;91(6):516-531. doi:10.3390/arm91060038Zappa C, Mousa SA.Non-small cell lung cancer: current treatment and future advances.Transl Lung Cancer Res. 2016;5(3):288-300. doi:10.21037/tlcr.2016.06.07Ramaswamy A.Lung cancer screening: review and 2021 update.Curr Pulmonol Rep. 2022;11(1):15-28. doi:10.1007/s13665-021-00283-1U.S. Preventive Services Task Force.Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement.JAMA.2021;325(10):962–970. doi:10.1001/jama.2021.1117Wolf AMD, Oeffinger KC, Shih TY, et al.Screening for lung cancer: 2023 guideline update from the American Cancer Society.CA Cancer J Clin. 2023;10.3322/caac.21811. doi:10.3322/caac.21811Chandran U, Reps J, Yang R, Vachani A, Maldonado F, Kalsekar I.Machine learning and real-world data to predict lung cancer risk in routine care.Cancer Epidemiol Biomarkers Prev. 2023;32(3):337-343. doi:10.1158/1055-9965.EPI-22-0873
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
National Institute on Drug Abuse. Tobacco, Nicotine, and E-Cigarettes Research Report.What are the physical health consequences of tobacco use?Centers for Disease Control and Prevention, Division of Cancer Prevention and Control.Lung cancer risk factors.Centers for Disease Control and Prevention.Lung cancer among people who never smoked.Centers for Disease Control and Prevention.What are the risk factors for lung cancer?Centers for Disease Control and Prevention.Smoking and Cancer.Centers for Disease Control.Benefits of quitting smoking.Bruder C, Bulliard JL, Germann S, et al.Estimating lifetime and 10-year risk of lung cancer.Prev Med Rep.2018;11:125-30. doi:10.1016/j.pmedr.2018.06.010Kuśnierczyk P.Genetic differences between smokers and never-smokers with lung cancer.Front Immunol. 2023;14:1063716. doi:10.3389/fimmu.2023.1063716Dong X, Zhang L, Milholland B, et al.Accurate identification of single-nucleotide variants in whole-genome-amplified single cells.Nat Methods. 2017;14(5):491-493. doi:10.1038/nmeth.4227Centers for Disease Control and Prevention.Health effects of cigarettes: cancer.Sahu R, Shah K, Malviya R, et al.E-cigarettes and associated health risks: an update on cancer potential.Adv Respir Med. 2023;91(6):516-531. doi:10.3390/arm91060038Zappa C, Mousa SA.Non-small cell lung cancer: current treatment and future advances.Transl Lung Cancer Res. 2016;5(3):288-300. doi:10.21037/tlcr.2016.06.07Ramaswamy A.Lung cancer screening: review and 2021 update.Curr Pulmonol Rep. 2022;11(1):15-28. doi:10.1007/s13665-021-00283-1U.S. Preventive Services Task Force.Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement.JAMA.2021;325(10):962–970. doi:10.1001/jama.2021.1117Wolf AMD, Oeffinger KC, Shih TY, et al.Screening for lung cancer: 2023 guideline update from the American Cancer Society.CA Cancer J Clin. 2023;10.3322/caac.21811. doi:10.3322/caac.21811Chandran U, Reps J, Yang R, Vachani A, Maldonado F, Kalsekar I.Machine learning and real-world data to predict lung cancer risk in routine care.Cancer Epidemiol Biomarkers Prev. 2023;32(3):337-343. doi:10.1158/1055-9965.EPI-22-0873
National Institute on Drug Abuse. Tobacco, Nicotine, and E-Cigarettes Research Report.What are the physical health consequences of tobacco use?
Centers for Disease Control and Prevention, Division of Cancer Prevention and Control.Lung cancer risk factors.
Centers for Disease Control and Prevention.Lung cancer among people who never smoked.
Centers for Disease Control and Prevention.What are the risk factors for lung cancer?
Centers for Disease Control and Prevention.Smoking and Cancer.
Centers for Disease Control.Benefits of quitting smoking.
Bruder C, Bulliard JL, Germann S, et al.Estimating lifetime and 10-year risk of lung cancer.Prev Med Rep.2018;11:125-30. doi:10.1016/j.pmedr.2018.06.010
Kuśnierczyk P.Genetic differences between smokers and never-smokers with lung cancer.Front Immunol. 2023;14:1063716. doi:10.3389/fimmu.2023.1063716
Dong X, Zhang L, Milholland B, et al.Accurate identification of single-nucleotide variants in whole-genome-amplified single cells.Nat Methods. 2017;14(5):491-493. doi:10.1038/nmeth.4227
Centers for Disease Control and Prevention.Health effects of cigarettes: cancer.
Sahu R, Shah K, Malviya R, et al.E-cigarettes and associated health risks: an update on cancer potential.Adv Respir Med. 2023;91(6):516-531. doi:10.3390/arm91060038
Zappa C, Mousa SA.Non-small cell lung cancer: current treatment and future advances.Transl Lung Cancer Res. 2016;5(3):288-300. doi:10.21037/tlcr.2016.06.07
Ramaswamy A.Lung cancer screening: review and 2021 update.Curr Pulmonol Rep. 2022;11(1):15-28. doi:10.1007/s13665-021-00283-1
U.S. Preventive Services Task Force.Screening for Lung Cancer: US Preventive Services Task Force Recommendation Statement.JAMA.2021;325(10):962–970. doi:10.1001/jama.2021.1117
Wolf AMD, Oeffinger KC, Shih TY, et al.Screening for lung cancer: 2023 guideline update from the American Cancer Society.CA Cancer J Clin. 2023;10.3322/caac.21811. doi:10.3322/caac.21811
Chandran U, Reps J, Yang R, Vachani A, Maldonado F, Kalsekar I.Machine learning and real-world data to predict lung cancer risk in routine care.Cancer Epidemiol Biomarkers Prev. 2023;32(3):337-343. doi:10.1158/1055-9965.EPI-22-0873
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.Cookies SettingsAccept All Cookies
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.
Cookies SettingsAccept All Cookies
