Smoking status should influence lung cancer staging, new study shows
The University of Kentucky Markey Cancer Center’s Graham Warren, M.D., Ph.D., and international collaborators led a groundbreaking study that could change the way lung cancer is diagnosed and treated.
The research, published in the Journal of Thoracic Oncology Sept. 8, found that patients’ smoking status at the time of lung cancer diagnosis has such a profound impact on their survival that it should be considered when staging lung cancer.
Cancer staging, which doctors determine at diagnosis, is based on factors including a tumor’s size, location and whether it has spread in the body. Staging helps predict prognosis and plan treatment. Smoking is the leading cause of lung cancer, and continued smoking after diagnosis worsens treatment outcomes. This profound impact on survival led Warren and his international colleagues to examine whether smoking status could influence traditional lung cancer staging.
The study, which analyzed data from nearly 49,000 lung cancer patients across 25 countries that were used to define current lung cancer staging, showed that smoking status may be more important than some of those traditional staging factors in determining prognosis for lung cancer.
“Smoking has such a significant effect on lung cancer survival that we wanted to look at how it affects staging,” said Warren, professor and vice chair of clinical research in the UK College of Medine’s Department of Radiation Medicine. “This study shows that smoking can have a substantial effect on survival for lung cancer staging, and by demonstrating this importance, it can change how we approach cancer diagnosis and treatment decisions.”
The study revealed that patients who currently smoke or formerly smoked have survival rates similar to patients in the next higher cancer stage who never smoked. Survival rates for patients who currently smoke were 39% lower compared to those who never smoked, and 32% lower for patients who formerly smoked.
The study used advanced statistical analysis to compare the importance of smoking status against traditional staging factors. Among patients with early-stage disease, smoking history had a greater impact on prognosis than whether cancer had spread to nearby lymph nodes.
The findings support the urgent need for smoking cessation programs to be integrated into cancer care, especially in Kentucky, where smoking and lung cancer rates remain among the highest in the nation. A parallel study published in JAMA Oncology and led by Warren and collaborators at MD Anderson Cancer Center shows that quitting smoking within six months after a cancer diagnosis improved median survival by approximately four years across cancer as a whole.
“Together, these results demonstrate the critical need to consider smoking as an important factor that affects cancer treatment, and that quitting smoking must be a core component of evidence-based cancer treatment.”
Warren recently re-joined Markey Cancer Center, as the director for Markey’s Tobacco in Research, Universal Screening, and Treatment (TRUST) initiative, which aims to improve health across the continuum of cancer care and tackling smoking cessation efforts across the Commonwealth as a top priority.
“Addressing smoking across Kentucky is one of the most effective methods we can use to improve patient outcomes, extend survival, and reduce costs associated with cancer treatment,” Warren said. “If we can prevent and treat the effects of smoking, this will be one of the most significant health advances we can deliver for our patients and families across Kentucky.”
Implications of the study extend beyond lung cancer treatment. The research team organized by the International Association for the Study of Lung Cancer plans to explore incorporating smoking status into the tenth edition of the international lung cancer staging system — potentially changing how cancer is diagnosed and treated worldwide.
