Cigarette Smoking and Survival in Pancreatic Cancer
A study of data from large prospective U.S. cohorts has shown that current cigarette smoking, greater pack-years, and heavy smoking were associated with poorer survival among patients with pancreatic cancer. The study was reported by Yuan et al in the Journal of Clinical Oncology.
Study Details
In the study, survival was analyzed by smoking status among 1,037 patients from the Health Professionals Follow-Up Study and Nurses’ Health Study diagnosed from 1986 to 2013. Survival by prediagnostic circulating levels of cotinine, a nicotine metabolite that is proportional to tobacco smoke exposure, was also analyzed among 485 patients from these 2 cohorts and the Physicians’ Health Study I and the Women’s Health Initiative. Patients were classified as nonsmokers (≤ 3.1 ng/mL), light smokers (3.1–20.9 ng/mL), or heavy smokers (≥ 21.0 ng/mL), according to prediagnosis cotinine levels. Hazard ratios (HRs) for death were calculated using Cox proportional hazards models adjusting for age, sex, race/ethnicity, body mass index, diabetes status, diagnosis year, and cancer stage.
Smoking and Mortality Risk
Current smokers had a significantly increased risk for death vs never smokers (HR = 1.37, P = .003). A significant negative trend was observed for poorer survival with increasing pack-years of smoking (P = .008 for trend), with a hazard ratio for death of 1.49 (95% confidence interval [CI] = 1.05–2.10) for > 60 pack-years vs never smoking; hazard ratios were 1.25 (95% CI = 0.75–2.06) for 1 to 30 pack years and 1.32 (95% CI = 1.00–1.75) for 31 to 60 pack-years. Survival among former smokers was similar to that for never smokers (HR = 0.99, P = .90); no difference in the risk with time since stopping was observed, with hazard ratios of 0.90 (95% CI = 0.66–1.22) for stopping within the past 5 years, 1.15 (95% CI = 0.85–1.56) for 5 to 10 years, and 1.00 (95% CI = 0.86–1.16) for > 10 years.
In an analysis by prediagnostic circulating cotinine levels, heavy smokers had an increased risk of death vs nonsmokers (HR = 1.76, 95% CI = 1.23–2.51), whereas an increased risk was not significant among light smokers (HR = 1.29, 95% CI = 0.89–1.86). Among patients with circulating cotinine levels measured within 5 years before diagnosis, the hazard ratio for heavy smokers vs nonsmokers was 2.47 (95% CI = 1.24–4.92).
The investigators concluded: “Cigarette smoking was associated with a reduction in survival among patients with pancreatic cancer.”
The study was supported by the National Cancer Institute, Robert T. and Judith B. Hale Fund for Pancreatic Cancer, Perry S. Levy Fund for Gastrointestinal Cancer Research, Lustgarten Foundation, Pancreatic Cancer Action Network, Noble Effort Fund, Peter R. Leavitt Family Fund, Wexler Family Fund, and Promises for Purple.
Brian M. Wolpin, MD, MPH, of the Dana-Farber Cancer Institute, is the corresponding author of the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
