A new study shows that a history of smoking affects survival in patients with cancer of the head and neck. Patients who had smoked fewer than 100 cigarettes in their lifetime were three times more likely to have better overall survival, disease-specific survival, and recurrence-free survival compared with patients who had a current or previous history of regular smoking.
There are approximately 38,000 new cases of head and neck cancer cases in the U.S. each year, the vast majority of which occur in smokers.
The study, to be published October 1 in the Journal of Clinical Oncology, is the first to compare survival in pairs of head and neck cancer patients who differ in smoking status but are matched for other factors. The study provides a more accurate assessment of the link between smoking status and survival by limiting other factors that could affect observed disease outcome.
“These findings support previous studies indicating that molecular differences exist between the tumors of smokers and non-smokers and may actually reflect two separate types of head and neck cancer,” said Erich M. Sturgis, MD, MPH, in the Department of Head and Neck Surgery at the University of Texas M. D. Anderson Cancer Center and senior author of the study. “Our study suggests that the changes that occur in smokers may lead to a more aggressive form of the disease that results in poorer survival.”
Although the relative risk of developing head and neck cancer is three to 12 times higher for smokers than for non-smokers, the impact of smoking on disease outcome is unclear. Past studies have had difficulty measuring the effect of smoking status on survival because non-smokers who develop the disease generally differ demographically than patients with a previous or current history of smoking.
In the current study, researchers used a database of more than 500 patients with newly diagnosed, previously untreated head and neck cancer, including 83 non-smokers. Each non-smoker was paired with a smoker with similar age, sex, tumor location, disease stage, lymph node status, and treatment history. Applying these matching criteria yielded 50 pairs of head and neck cancer patients for further study. Several other factors, including alcohol use, additional medical conditions, and cancer-associated symptoms such as weight loss, earache, and difficulty swallowing were not included as matching criteria, but were statistically evaluated to assess their impact on survival.
Researchers found that the risk of death, death due to the disease, and disease recurrence was more than three times higher for people with a history of smoking.
Researchers underscored the importance of aggressively promoting tobacco cessation and moderation of alcohol use, as well as managing disease symptoms and other medical conditions in order to improve the quality of life and survival of people living with head and neck cancer.