• Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine in St Louis, St Louis, Missouri.

IMPORTANCE: There is a paucity of large-scale prospective studies evaluating the risk of developing head and neck cancer (HNC) associated with smoking, drinking, and dietary habits.

OBJECTIVE: To determine the association of smoking, drinking, and dietary habits with the risk of developing HNC.

DESIGN, SETTING, AND PARTICIPANTS: A nested cohort survival analysis of Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial participants was performed. Participants were between 55 and 74 years of age and recruited at 10 centers across the US from November 1993 to July 2001. Participants who developed HNC were matched with controls based on demographics and family history of HNC for analysis of smoking habits; for the analysis of drinking and dietary habits, matching was performed on smoking status and duration in addition to demographics and family history of HNC. Data analysis was performed from January to November 2023.

EXPOSURES: Smoking, drinking, and dietary habits.

MAIN OUTCOME AND MEASURE: Diagnosis of HNC.

RESULTS: In total, 139 926 participants (51% female; mean [SD] age, 62.6 [5.4] years) were included in the analysis of smoking habits with a median (IQR) follow-up time of 12.1 (10.3-13.6) years, 571 of whom developed HNC. HNC risk associated with smoking increased the closer the proximity of the head and neck subsite to the lungs, with the greatest risk associated with smoking observed in laryngeal cancer (current smoker hazard ratio [HR], 9.36; 95% CI, 5.78-15.15 compared to a nonsmoker). For analysis of drinking and dietary habits, 94 466 participants were included in the analysis of smoking habits with a median (IQR) follow-up time of 12.2 (10.5-13.6) years, 264 of whom developed HNC. HNC risk increased with heavy drinking (HR, 1.85; 95% CI, 1.44-2.38) and decreased with consumption of whole grains (HR, 0.78; 95% CI, 0.64-0.94/oz per day), whole fruits (HR, 0.90; 95% CI, 0.82-0.98/cup per day), and overall healthy eating, as scored by Healthy Eating Index 2015 (HR, 0.87; 95% CI, 0.78-0.98/10 points).

CONCLUSIONS AND RELEVANCE: In this nested cohort study, the risk of HNC associated with smoking was higher for subsites that were closer to the lungs; heavy drinking was associated with greater HNC risk, while healthy eating was associated with a modest reduction in HNC risk.