You are using an outdated browser. We suggest you update your browser for a better experience. Click here for update.
Close this notification.
Skip to main content Skip to search
CCO Blog (Admin View)

Why it’s so important to quit smoking when you have cancer

Dr. Bill Evans
Insights & Perspectives 6 minute read

If you’ve been diagnosed with cancer or had a loved one receive this news, you know that it can be quite overwhelming. There are often multiple clinic visits and tests, new healthcare providers to get to know and lots of information about treatment options and their side effects. And there is the stress of not knowing how well the treatments will work or what your prognosis will be.

As a former oncologist, I wanted the best possible care and outcomes for my patients. I knew that for my patients who used tobacco, one of the best things they could do to help their cancer treatment work better was to quit smoking or remain smoke free.

I realize that it is a very stressful time when you receive a diagnosis of cancer, and the last thing you may want to think about is quitting smoking.

But I can’t stress enough how important it is.

Let me tell you why.



Dr. Bill Evans is a medical oncologist with a special interest in lung cancer. He has practised in Toronto, Ottawa and Hamilton and is currently Cancer Care Ontario's Clinical Advisor on Smoking Cessation.

General health benefits

We know that there are many benefits to your health to quitting smoking even after a cancer diagnosis.

Quitting smoking helps your heart and lungs to function better and that will help you to feel better:

  • Within 20 minutes of your last cigarette, your heart rate and blood pressure will begin to drop
  • Within 2-12 weeks, your lung function will increase
  • Within 1-9 months, coughing and shortness of breath will decrease

And there are important long-term benefits. Within 1 year, your risk of heart disease is cut in half.

But what is really important for you as a cancer patient is that the treatment you will receive for your cancer will work better and you will reduce your risk of bad side effects.

More effective cancer treatments

If you’re having surgery, quitting smoking or reducing the number of cigarettes you smoke can make surgery safer and help you recover more quickly, with less risk of postoperative complications like wound infections or pneumonia.

If you’re having radiation therapy, the radiation works better when the level of oxygen in your body is normal. When you smoke, the level of oxygen in your blood drops, making it harder for radiation therapy to do its job.

And if you’re having chemotherapy, tobacco smoke has chemicals in it that can reduce the levels of some chemotherapy drugs, making them less effective.

Keep trying and don’t give up – help is available

Smoking is not a bad habit. It’s an addiction to the nicotine in cigarettes. Withdrawal from nicotine produces cravings that make it very difficult to quit. 

However, many options are available to you once you make the decision to quit smoking:

  • Nicotine Replacement Therapy (NRT): There are a variety of ways you can use NRT. Combining long-acting therapy (the nicotine patch) with short-acting products like gum, lozenges, mouth spray and inhalers can reduce withdrawal symptoms.
  • Non-nicotine prescription medications: Two prescription drugs are available to help reduce nicotine cravings and prevent relapse: varenicline and bupropion. 
  • Counselling: Many people find it helpful to speak to a smoking cessation counsellor or coach in person, by phone or online.
  • Self-help guides: You can get brochures and fact sheets from many sources, including your cancer care team.  

The best way to quit smoking is to receive help from a smoking cessation counsellor and to take medication to reduce cravings. If you do this, it can triple your chances of success.

Cancer Care Ontario wants you to get the best possible outcome from your cancer treatment. This brochure outlines the benefits of quitting smoking for people with cancer. There are also videos which can be accessed on our webpage dedicated to smoking cessation.

How can you quit smoking or stay smoke free?

Start by talking to:

  • Your cancer care team
  • Your family doctor or nurse
  • Your pharmacist
  • A Quit Coach at or 1-877-513-5333.

Have a question about this blog? Email us at