How Smoking Affects Cancer Treatment—and 3 Tips for Quitting

The health risks of smoking are startling. The Centers for Disease Control finds that 9 out of 10 cases of lung cancer are caused by smoking.1 According to the National Cancer Institute, smoking causes about 480,000 premature deaths each year in the United States.2 And, according to the American Cancer Society, smoking causes 30% of all cancer deaths in the United States.3

On its own, a cancer diagnosis is a serious, potentially life-threatening illness, and the correlation between smoking and cancer has been comprehensively documented. A significant and unique challenge persists for patients with cancer who have smoked before their diagnosis and continue to smoke through treatment and recovery. A study commissioned by the National Institutes of Health found that among 947 patients with a variety of different cancers followed throughout their treatment and for 6 months after treatment completion, patients who continued to smoke reported a significantly higher level of adverse reactions and side effects.4

Continuing to smoke throughout treatment can actually hinder recovery. Research published in the Proceedings of the National Academy of Sciences of the United States of America found that nicotine protects anti-cancer agents and people who continue to smoke throughout treatment have a lower survival rate than those who have quit. The study concluded that nicotine in any form may reduce the effectiveness of the treatment.5

While smoking can have a particularly strong impact on patients with lung cancer, in all likelihood, smoking will make your cancer treatment more challenging. Quitting smoking can be extremely difficult, but there are strategies that can make it easier to accomplish. Here are a few tips to quit tobacco and remain smoke-free.

Tip 1: Pick a “quit day”

The longest journey starts with one step. Picking a quit date (preferably, as soon as possible) will allow you to prepare for withdrawal and reach out to friends and family for support. It can be helpful to have your support system set up in advance so that they know what you're going through and can prepare themselves to help you.

If you slip up, make the very next day your quit day. Quit days can become quit weeks, quit months, and so on. Don't be too hard on yourself, but avoid pushing your quit day too far off.

Tip 2: Withdrawal symptoms, though challenging, will pass

According to Addictions and Recovery, a nonprofit resource for drug and alcohol addiction recovery, there are 2 milestones anyone who has quit tobacco should keep in mind: first, the strongest symptoms you feel will likely happen within the first 2 to 3 days; and second, it takes at least 3 months for your brain chemistry to return to normal after you stop smoking. Headaches, difficulty concentrating, and food cravings also tend to subside within those first 2 months. The longest lasting withdrawal symptoms are generally irritability and lethargy, so don't be surprised if those symptoms stick around for a while after your quit date -- but hang in there, because they will eventually subside, too.6

Tip 3: Stay active

According to, quitting tobacco and staying tobacco-free become more manageable if you keep your mind and body active. They recommend activities such as physical exercise, chewing gum, drinking lots of water, going to a movie—basically, anything to keep your mind off tobacco while you are experiencing withdrawal symptoms.7

Quitting won't be easy, but these tips should be a starting point. For more information and additional resources on how to quit while going through cancer treatment, visit Memorial Sloan-Kettering Cancer Center's Guide to Quitting Smoking.



1. Smoking and cancer. Centers for Disease Control and Prevention. Accessed February 22, 2018.
2. Harms of cigarette smoking and health benefits of quitting. National Cancer Institute. Accessed February 22, 2018.
3. Health risks of smoking tobacco. American Cancer Society. Accessed February 22, 2018.
4. Peppone LJ, et al. The effect of cigarette smoking on cancer treatment-related side effects. The Oncologist, 2011;16(12):1784-1792. doi:10.1634/theoncologist.2011-0169.
5. Nicotine inhibits apoptosis induced by chemotherapeutic drugs by up-regulating XIAP and survivin. Proceedings of the National Academy of Sciences of the United States of America. Accessed April 30, 2018.
6. How to quit smoking - 8 steps to quitting for good. Addictions and Recovery. Accessed February 22, 2018.
7. Steps to manage quit day. Accessed February 22, 2018. 



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