It’s a well-established fact that smoking is harmful to health, but new research suggests that quitting smoking can have a profound effect even for those diagnosed with late-stage cancer, significantly improving survival odds. In fact, experts say that it’s never too late for cancer patients to quit smoking, and the health benefits are considerable, even in advanced stages of the disease.
The groundbreaking study, published on October 9, 2025, in the Journal of the National Comprehensive Cancer Network, shows that patients with advanced cancer who quit smoking after their diagnosis lived nearly a full year longer compared to those who continued smoking. This new evidence adds weight to the long-standing message that quitting smoking has undeniable benefits, even for those already battling one of the most life-threatening conditions.
The Study: A Closer Look at the Findings
The study followed more than 13,000 cancer patients who were treated at the Siteman Cancer Center in St. Louis, Missouri, between June and December 2018. Researchers tracked the smoking habits of these patients, focusing on whether they quit smoking after their cancer diagnosis. According to the findings, approximately 13% of the patients in the study were smokers when they first visited the cancer treatment center.
Interestingly, only 20% of those smokers successfully quit within six months of their diagnosis. However, the results of the study showed that those who managed to quit smoking were nearly twice as likely to survive beyond two years compared to those who continued smoking. The researchers noted that the patients who quit smoking gained a significant survival advantage—about a year more of life—compared to their smoking counterparts.
Experts Weigh In: Quitting Smoking is Vital for Cancer Patients
Dr. Li-Shiun Chen, the senior researcher behind the study and director of the smoking cessation program at Siteman Cancer Center, emphasized the importance of smoking cessation for cancer patients. “It is never too late, and no one is ever ‘too sick’ to quit smoking,” Dr. Chen said in a statement. “Individuals with cancer who stop smoking after their diagnosis live significantly longer than those who continue smoking, even when their cancer is at an advanced stage.”
Dr. Steven Tohmasi, the lead researcher and surgical resident at Siteman Cancer Center, also highlighted the significance of this finding. “Lifestyle changes such as quitting smoking can prolong survival even more than some chemotherapies,” he stated. “Our research reinforces the idea that smoking cessation should be considered the fourth pillar of cancer care—alongside surgery, radiation therapy, and chemotherapy/immunotherapy.”
A Game-Changer for Cancer Care
The study’s findings suggest that smoking cessation should be incorporated as an integral part of cancer treatment, much like surgery, chemotherapy, and radiation therapy. According to the researchers, quitting smoking should no longer be seen as an optional add-on to treatment, but rather as a crucial part of the care plan. By making smoking cessation a core part of cancer treatment, healthcare providers can potentially maximize patients’ survival rates and improve their quality of life.
Dr. Tohmasi went on to say, “By doing so, we can maximize survival, improve quality of life, and truly deliver comprehensive oncology care.” The research also suggests that smoking cessation could play a more significant role in extending life expectancy than some chemotherapies.
A Huge Impact: Experts React
The impact of smoking cessation on cancer patients has been widely acknowledged by other medical experts. Dr. James Davis, the medical director of the Center for Smoking Cessation at the Duke Cancer Institute in North Carolina, referred to the study’s findings as demonstrating a “huge effect” on cancer patients’ survival chances.
Dr. Davis cautioned that because the study is observational, it doesn’t prove direct causality, meaning the research cannot definitively claim that quitting smoking saved lives. However, he acknowledged the substantial impact smoking cessation has on cancer patients’ health. “We can say, however, that in the context of what we already know about smoking and cancer, this study suggests a profound impact of smoking cessation before and after a person develops cancer,” Dr. Davis explained.
The overall message is clear: quitting smoking dramatically reduces the risk of developing cancer and, for those already diagnosed, quitting can extend life and improve outcomes. The American Cancer Society has long advocated for smoking cessation as part of cancer prevention and treatment.
Understanding the Connection Between Smoking and Cancer
The relationship between smoking and cancer is well-documented. Smoking is a leading cause of several types of cancer, including lung cancer, mouth cancer, throat cancer, and bladder cancer. Smoking not only increases the risk of cancer but can also worsen the prognosis for those already diagnosed with cancer. It weakens the immune system and hampers the body’s ability to recover from cancer treatments.
However, the new study proves that even for those with late-stage cancer, quitting smoking offers substantial benefits. The body begins to repair itself almost immediately after quitting, reducing the harmful effects of smoking on the organs and tissues. This leads to better treatment outcomes, fewer complications, and improved survival odds.
What the Study Means for Cancer Care Moving Forward
This study has the potential to reshape how cancer care is approached, especially when it comes to integrating smoking cessation into treatment plans. While smoking cessation programs are already available in many healthcare settings, they often aren’t a priority in cancer care. This study emphasizes the importance of making quitting smoking a key part of the treatment process for cancer patients, regardless of the stage of their illness.
Future cancer care must focus on more than just surgeries and chemotherapy. It should include a comprehensive plan that addresses all lifestyle factors, including smoking. The study suggests that incorporating smoking cessation into the treatment plan could be a game-changer in improving survival rates and overall well-being.
Key Takeaways:
- Quitting Smoking Improves Cancer Survival: The study reveals that quitting smoking can nearly double cancer patients’ chances of survival, even for those with advanced-stage cancer.
- Smoking Cessation is Crucial for Cancer Care: Experts suggest that smoking cessation should become a core component of cancer care, alongside surgery, radiation therapy, and chemotherapy.
- Smoking Has Profound Effects on Cancer Prognosis: Smoking weakens the body’s immune system, making it harder for cancer patients to recover from treatment and increasing the risk of complications.
- Healthcare Providers Should Promote Smoking Cessation: The study highlights the need for healthcare providers to prioritize smoking cessation as part of their cancer care plans, helping patients to maximize their chances of survival and improve their quality of life.
