A new study from Yale Cancer Center has found that 15% of people diagnosed with cancer in 2023 were still smoking at the time of their diagnosis.
The research, published in JAMA Oncology, also revealed that nearly half of cancer patients had a history of smoking.
These findings highlight how strongly tobacco use is linked to cancer and how important it is to support patients in quitting after diagnosis.
The research team used data from the National Cancer Database (NCDB), the largest cancer database in the U.S., which began collecting information about patients’ smoking status in 2023.
The NCDB is used by doctors across the country to understand how different factors affect cancer treatment and outcomes.
Including smoking status helps physicians and researchers learn more about how smoking may impact the effectiveness or safety of certain treatments.
Smoking is known to increase the risk of many cancers, including those of the lung, mouth, throat, esophagus, and liver.
Around 12% of the general U.S. population currently smokes, but among cancer patients in the study, that number was much higher. About 47% of those diagnosed with cancer in 2023 were either current or former smokers—almost four times the national average.
This sharp difference shows just how closely tied smoking is to cancer development.
Dr. Daniel Boffa, the lead author and a thoracic surgeon at Yale School of Medicine, explained that this data is vital for improving care. In some types of cancer, like lung cancer in non-smokers, targeted therapies work especially well. But if a patient has a smoking-related cancer, treatment decisions may need to be different.
Boffa also emphasized that a cancer diagnosis is a critical moment to help people quit smoking. Stopping smoking can lead to better treatment results, fewer side effects, and longer survival. In fact, quitting can sometimes do more for a patient’s outcome than the latest medical treatments.
The study also found that smoking rates among cancer patients vary by region. States like Kentucky, Tennessee, Alabama, and Mississippi had the highest number of current smokers at diagnosis. This suggests a need to bring more smoking cessation resources to areas where they’re needed most.
By understanding who is most affected and where support is lacking, doctors and policymakers can work together to improve cancer care—and save lives.
