Do You Really Need to Quit Smoking and Drinking During Cancer Treatment in 2026?

Yes—quitting or cutting back as much as possible on both tobacco and alcohol is recommended. Continuing to smoke or drink after diagnosis is associated with a higher risk of recurrence and second cancers, and may also reduce how well treatment works.

Key Takeaways

• Continuing to smoke after diagnosis is linked to a higher risk of recurrence or second cancers, poorer treatment response, and increased treatment-related side effects (U.S. National Cancer Institute, NCI).
• Alcohol may also raise the risk of recurrence or second cancers, so drinking during and after treatment should be discussed with your care team (NCI).
• Korea's National Cancer Prevention Guidelines include avoiding tobacco and secondhand smoke, and avoiding even small amounts of alcohol for cancer prevention (National Cancer Information Center).
• Cancer patients are advised to have their smoking status checked regularly and to receive both smoking-cessation counseling and medication support together (NCI).

Isn't It Too Late to Quit Smoking Now?

It's not too late. Even quitting right before treatment can help you tolerate it better, and regardless of when you quit, continuing to smoke after diagnosis is itself associated with higher risk of recurrence/second cancers and reduced treatment response (NCI). The preparation period before treatment begins is described as a good time to start quitting smoking, alongside maintaining weight, getting enough protein, and scheduling a dental checkup (National Cancer Information Center).

Does Alcohol Have to Be Completely Off-Limits, or Is a Little Okay?

Whether complete abstinence is necessary varies by individual situation, so this should be discussed with your care team. Alcohol may increase the risk of recurrence or second cancers, and starting to drink for any reason if you currently don't drink is not recommended (NCI). Korea's National Cancer Prevention Guidelines also recommend avoiding even small amounts of alcohol for cancer prevention (National Cancer Information Center).

Do I Need to Keep This Up Even After Treatment Ends?

Yes, these habits continue after treatment finishes. Cancer survivorship care guidelines list smoking cessation and reduced alcohol intake, along with regular exercise and a balanced diet, as basic measures to lower the risk of recurrence, second cancers, and late side effects (National Cancer Information Center, NCI). Some chemotherapy drugs and chest radiation therapy can cause heart failure, coronary artery disease, or bone thinning years later, so quitting smoking, reducing alcohol, managing weight, and getting adequate calcium and vitamin D are recommended together (NCI).

FAQ — Does Quitting Smoking or Drinking Actually Affect Treatment Outcomes?

Yes—continuing to smoke after diagnosis is cited as evidence-linked to higher risk of recurrence or second cancers, poorer treatment response, and more treatment-related side effects (NCI). Alcohol is also described as a factor that may raise the risk of recurrence or second cancers, so it's best to discuss the specific extent with your care team based on your individual treatment plan and health status.

FAQ — I'm Struggling to Quit Smoking. Can I Get Help?

Yes, you don't have to tough it out alone. Cancer patients are advised to have their smoking status checked regularly and to receive both counseling and medication support together (NCI). If you mention that you currently smoke early on during treatment at a Korean hospital, you can be guided toward smoking-cessation counseling and supportive therapies.

Sources and Notes

• This article was written based on notes regarding pre-treatment nutrition and physical preparation, and cancer survivorship care (National Cancer Information Center, U.S. National Cancer Institute, NCI).
• This content is intended for general medical information purposes only. Diagnosis, treatment approach, and outcomes may vary depending on individual condition. Please consult your medical team for an accurate diagnosis and treatment decisions.