Top 10 Reasons to Quit Smoking if You Have Cancer

If you have been diagnosed with cancer, cigarette smoking while being treated with chemotherapy or radiation can be very harmful. You should stop smoking the moment you are diagnosed with cancer, particularly lung cancer. But doing so can be incredibly difficult for some, particularly heavy smokers who have been smoking for years.

Doctor holding a broken cigarette
quintanilla / Istockphoto

According to a 2019 review in Translational Lung Cancer Research, the majority of people with lung cancer will attempt to quit after a lung cancer diagnosis, but only 50% of them remain off cigarettes permanently.

Beyond the challenges of nicotine addiction, people with cancer are often less motivated to quit if the disease is advanced or they believe that their long-term outlook is poor. Younger age, depression, pain, anxiety, and the side effects of treatment may also dissuade a person from quitting post-diagnosis.

If you have cancer, it is important to remember that it's never too late to quit—and that there are very good reasons to do so. Here are 10 ways quitting can improve your life if you've been diagnosed with lung cancer or any other type of cancer.

Increased Survival Times

Tobacco smoking accounts for at least 30% of all cancer deaths and nearly 90% of all lung cancer deaths. Quitting at any stage of the disease can make a huge difference in your overall chances of survival.

A study published in the journal Oncology reported that, among 250 people with advanced lung cancer, the median survival time for those who quit was 28 months versus 18 months for those who continued to smoke.

Median survival is the length of time in which half of the people in a group are still alive following the initial diagnosis. What this means is that many people with advanced lung cancer can live 28 months or more if they quit.

Quitting cigarettes is not only beneficial to people with lung cancer but can improve survival times in those with breast, prostate, colon, esophageal, cervical, endometrial, and ovarian cancer as well.

Reduced Risk of Death

Quitting smoking can not only increase survival times in people with cancer but also decrease the risk of death from all other causes (referred to as all-cause mortality).

Compared to former smokers with lung cancer, current heavy smokers with the disease have a higher all-cause risk of death. Among men who are heavy smokers, the risk is increased by 1.75-fold; among women, the risk is increased by nearly two-fold.

A 2014 study in the Journal of Breast Cancer Research similarly concluded that heavy smoking independently increased the all-cause risk of death in women with breast cancer from 32% to 56%.

The same has also been reported in people with testicular, colorectal, and prostate cancer.

Fewer Surgical Complications

Studies suggest that quitting cigarettes one year prior to major surgery all but eliminates the risk of post-operative death while reducing the risk of vascular and respiratory complications.

Surgery is an integral part of treatment in people with lung cancer, as it is with other types of solid tumor cancers. Quitting smoking can reduce the risk of post-surgical complications, some of which may be life-threatening or significantly reduce your quality of life.

According to a 2013 analysis in JAMA Surgery, no less than 21% of current smokers and 13% of former smokers experienced severe and potentially life-threatening complications following major surgery.

These included:

Not surprisingly, the risk is higher in current smokers than former smokers and tends to increase in tandem with the amount a person smokes (as measured by pack-years).

Improved Radiation Therapy

Radiation therapy used in the treatment of cancer does not appear to be as effective in people who smoke.

One of the reasons for this is that oxygenated tissues are needed for radiation to have its maximum effect. Oxygen produce molecules, called free radicals, that kill cancer cells. Smoking causes the persistent narrowing of blood vessels, reducing the amount of oxygen that reaches tissues. When oxygen levels are low, the impact of radiation therapy is reduced.

Smoking also prolongs and aggravates side effects of radiation, including mucositis (inflammation of mucosal tissues), xerostomia (dry mouth), xerosis (dry skin), ageusia (loss of taste), pneumonitis, and bone and soft tissue damage. It can also increase the risk of premature death in people who undergo high-dose chest irradiation.

According to a 2017 study in the Journal of Clinical Oncology, smokers with breast cancer who undergo radiation therapy have at least a four-fold increased risk of death from heart disease compared to a matched set of individuals who have never smoked.

By quitting cigarettes, the effects of radiation therapy are not only enhanced, but the risk of complications can also be reduced.

Improved Chemotherapy

Smoking can also decrease the effectiveness of chemotherapy by decreasing blood flow to the site of the tumor. Cigarettes have a vasoconstrictive effect, causing blood vessel narrowing that reduces the amount of the cancer-fighting drug that can reach cancer cells.

On top of this, smoking impairs liver function and can decrease the production of liver enzymes needed to metabolize (break down) chemotherapy drugs into their active metabolite.

Smoking cessation not only makes chemotherapy more effective, but it can also improve the overall prognosis.

A 2018 study from Brazil reported that quitting prior to chemotherapy improves survival times, especially in people with small cell lung cancers (a less common but more aggressive form of the disease). According to the researchers, people who stopped smoking had a median survival time of seven months compared to 2.5 months for those who didn't stop.

Improved Targeted Therapies

Targeted therapies are a newer category of drugs that recognize and attack cancer cells with specific genetic mutations. If you test positive for these mutations, you may be a candidate for therapies that can not only prolong survival times—but do so with fewer side effects than most chemotherapy drugs.

Studies suggest that smoking undermines the effectiveness of certain targeted drugs, most especially Tarceva (erlotinib), which is used in the treatment of pancreatic cancer and non-small cell lung cancer.

The reasons for this are not entirely clear, but it presumed that the vasoconstriction of blood vessels limits the amount of drug that reaches the target site. Of notable concern, the risk of resistance to targeted therapies remains high even among light smokers.

The only effective way to mitigate this risk is to quit cigarettes. This is especially true given that cancer cells can become resistant to targeted drugs quickly, often within six months. By kicking the habit, you can improve the duration of effectiveness and potency of the cancer-fighting drugs.

Faster Recovery From Treatment

Cancer therapies can take a toll on your body. Smoking has been shown to increase the severity and duration of many common side effects, even after treatment is finished.

According to a 2011 study in The Oncologist, people who continued smoking six months after the completion of therapy have a greater likelihood of severe symptoms compared to their non-smoking counterparts.

These include:

  • Concentration problems: 2.46-fold increased risk
  • Depression: 2.93-fold increased risk
  • Fatigue: 2.9-fold increased risk
  • Hair loss: 2.53-fold increased risk
  • Memory problems: 2.45-fold increased risk
  • Pain: 1.91-fold increased risk
  • Skin problems: 3.3-fold increased risk
  • Sleep problems: 3.1-fold increased risk
  • Weight loss: 2.19-fold increased risk

The researchers concluded that participants who quit had significant and sometimes profound improvements in symptom severity scores, highlighting the importance of smoking cessation in restoring health and quality of life after cancer treatment.

Reduced Risk of Second Cancers

Smoking can increase the risk of a second primary cancer. This is not cancer that has spread (metastasized) from the original tumor, but an entirely new cancer that is unrelated to the original one.

Studies suggest that the combination of smoking and cancer treatments can sometimes amplify this risk. Smoking can increase this risk, especially in people with thyroid cancer in whom the risk of a second cancer is more than doubled.

This is especially true with small cell lung cancers in which smoking and alkylating agents such as Cytoxan (cyclophosphamide) can increase the risk of a second cancer 19-fold.

Other studies have shown that people with head and neck cancers who smoke have a five-fold increased risk of a second primary cancer compared to counterparts who do not smoke.

In the same way that smoking cessation reduces the risk of tobacco-related cancers, it can reduce the risk of second primary cancers and help you avoid secondary treatments that tend to be less tolerable.

Protection of Family Members

Smoking doesn't just hurt the smoker, it also hurts those who live or work with them. Secondhand smoke is estimated to cause roughly 3,000 lung cancer deaths in the United States each year and, today it is the third leading cause of the disease behind radon exposure.

Scientists are also beginning to learn more about the impact of thirdhand smoke in which carcinogenic compounds from cigarettes can imbed themselves on surfaces, clothing, and objects for months and even years, posing health risks—to infants and toddlers, in particular.

By taking into account the impact of smoking on loved ones, behaviors can change. A 2016 study involving Black families found that shifting the conversation about the risks of smoking from the smoker to the smoker's children was considered the most effective motivation for quitting.

Cost Savings

Another common motivator for smoking cessation is cost. Consider that if you smoke a pack of cigarettes a day, you will end up spending around $5,000 by year's end. When undergoing cancer treatment, that amount of money can help cover out-of-pocket expenses for your health care and alleviate some of the stress that medical bills can bring.

A common fallacy among smokers is that the cost of smoking cessation aids, including Zyban (bupropion) and Chantix (varenicline), is exorbitant. What many fail to realize is that these and other smoking aids are classified as essential health benefits (EHBs) under the Affordable Care Act and may be fully covered by insurance.

Everyone finds the motivation to quit smoking for good in different places. Your wallet may the one that does this for you.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."