AACR II: Potential Link Between Lung Cancer Risk and Sleep Patterns
Posted: Saturday, June 27, 2020
People who sleep in on the weekends tend to experience an exhaustion called social jetlag, which occurs when the body’s biologic clock is disrupted. Not only does social jetlag affect the sleep-wake cycle, according to Lin Yang, PhD, of the University of Calgary, and colleagues, it may also increase a person’s risk for lung cancer. These results from a prospective cohort study, presented at the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting II (Abstract 4655/16), also found the highest risk for lung cancer in smokers with social jetlag.
“Our findings suggest a potential lung cancer risk associated with switching sleep patterns between work and free days among smokers,” wrote the authors. “Further studies are necessary to confirm these findings and elucidate the biologic mechanisms.”
From 2001–2015, the Alberta’s Tomorrow Project collected sleep pattern data from 19,436 Canadians. The study defined social jetlag as “the absolute difference in waking time between free day and workday that accounted for sleep debt.” A person’s social jetlag was categorized with a 0-hour difference (32.5%), more than 0–1 hours (32.4%), and more than 1–4 hours (35.0%). Researchers surveyed participants on their smoking habits along with a range of personal information, including but not limited to age, family history, and smoking behavior. In 2018, researchers gathered data on lung cancer cases through the Alberta Cancer Registry.
After a 9.6-year follow-up, the researchers found 117 lung cancer cases, which “yielded 179,028 person-years.” Using a multivariable-adjusted model, results showed a trend toward significance for social jetlag of more than 1–4 hours with lung cancer risk (P for trend = .047). Lung cancer risk was further increased in daily smokers with social jetlag (P for trend = .010) compared with never smokers (P for trend = .91) and former smokers (P for trend = .63).
Disclosure: The study authors reported no conflicts of interest.