Most people know that cigarette smoking gives you a higher risk of developing cancer. But not many people know that after a cancer diagnosis, any cancer, one should quit smoking. It's rarely mentioned. But quitting smoking means better cancer treatment response and survival.
The medical community is so aware of the risks of continued cigarette smoking, that they call quitting smoking the "fourth pillar of cancer care" (The other 3 pillars of cancer care are: surgery, radiation, and chemo/immunotherapy.) Research finds that for many types of cancer, quitting smoking improves treatment response and also long-term survival.
Unfortunately, most cancer patients are not told this by their health professionals. Which may be why more than half of persons getting a cancer diagnosis continue smoking.
But, continuing smoking increases the risk of death twofold within 6 months vs those who quit smoking after the cancer diagnosis. The cancers that have been shown to be affected by smoking after diagnosis include a variety of cancers, including head and neck, lung, colorectal, and bladder cancer.
Excerpts from Medscape: The ‘Fourth Pillar of Cancer Care’ That’s Often Missed
For patients with cancer who smoke tobacco, quitting may be one of the most impactful interventions available. Quitting smoking after a cancer diagnosis has been linked to better treatment response and improved overall survival.
Quitting is so effective that “my colleagues have called tobacco treatmente ‘fourth pillar of cancer care’ alongside surgery, radiation, and chemo/immunotherapy,” said clinical psychologist Jesse Kaye, PhD, assistant professor at the University of Wisconsin-Madison (UW) Department of Family Medicine and Community Health and the UW Center for Tobacco Research and Intervention.
Yet, despite decades of evidence and guideline recommendations, tobacco cessation treatment remains underused. Most patients never receive it, and survey data suggest that more than half of people who smoke continue after a cancer diagnosis.
The disconnect reflects a persistent gap in oncology: Effective strategies to improve quit rates and outcomes exist, but they are not routinely embedded into cancer care.
The evidence supporting tobacco treatment is remarkably consistent. Continuing to smoke has been linked to worse survival, while quitting improves outcomes across multiple cancer types.
A 2025 analysis, for instance, found that patients who continued smoking had an almost twofold higher risk for all-cause mortality than those who quit smoking within 6 months of their cancer diagnosis. At 2 years, 85% of patients who quit were alive compared with nearly 75% of those who continued smoking. These patterns held across studies assessing smoking cessation and cancer survival for a range of cancer types, including head and neck, lung, colorectal, and bladder cancer
With this body of evidence that smoking undermines the effectiveness of cancer treatment and reduces patient survival, “smoking should be assessed, documented, and treated with a sense of urgency,” said Jessica L. Burris, PhD, professor in the department of psychology and co-leader of the Cancer Prevention and Control Research Program at the University of Kentucky in Lexington.
The National Comprehensive Cancer Network has developed tobacco treatment guidelines for patients with cancer, and leading oncology organizations, including the American Society of Clinical Oncology and the American Association for Cancer Research, recommend screening for and treating tobacco use.
Still, “tobacco treatment has not been integrated into routine cancer care,” said Li-Shiun Chen, MD, MPH, ScD, professor of psychiatry at the Washington University School of Medicine and director of the Tobacco Treatment Program at Siteman Cancer Center, both in St. Louis.
If the evidence is so strong, why isn’t tobacco treatment routine oncology care?
Experts say the problem is not lack of evidence — it’s implementation.
A recent survey from Burris and colleagues found that many cancer programs accredited by the American College of Surgeons’ Commission on Cancer still were not routinely documenting smoking cessation treatment plans, providing counseling, prescribing cessation medications, or referring patients to tobacco treatment programs.
The reasons were largely practical. Programs cited inadequate staff training (68.8%), lack of tobacco treatment specialists (61.9%), perceived patient resistance (58.3%), insufficient staff time (42.4%), as well as inadequate funding (40.6%) and reimbursement (31%).
Even when cancer centers have a dedicated smoking cessation program, clinicians still need to identify patients and initiate referrals, which can create a potential bottleneck.
Experts hope to turn the tide with a new standard implemented earlier this year by the Commission on Cancer. The Commission on Cancer accredited programs are now required to provide tobacco screening and cessation assistance to all newly diagnosed cancer patients. All patients reporting current smoking during screening must be referred to or receive access to evidence-based smoking cessation treatment within 30 days.
Kaye called this standard “a gamechanger” because “it highlights that tobacco treatment is an essential part of routine cancer care.”
Experts said explaining the effect of smoking on cancer outcomes — not simply advising patients to quit — can be one of the strongest motivators for cessation.