Lung Cancer Risk in Female School Cooks: A Nationwide Retrospective Cohort Study in the Republic of Korea.

Background: Exposure to cooking fumes exposure likely increases the lung cancer risk in school cooks, but research on the incidence of lung cancer in school cooks is lacking. Therefore, this study aimed to examine a nationwide cohort of school cooks for lung cancer by linking three Korean social insurance databases to determine whether working as a school cook increases lung cancer risk. Methods: A nationwide retrospective cohort of school cooks and clerks with lung cancer was established by linking Employment Insurance, Industrial Accident Compensation Insurance, and National Health Insurance Service databases. Covariates were matched using 1:1 propensity score matching (PSM) for school cooks and clerks. Age-standardized incidence and hazard ratios (HRs) for lung cancer were calculated using the Cox proportional hazards model. Fine-Gray subdistribution HRs were used for sensitivity analysis. After further categorization into never- and ever-smoked subcohorts, the same analyses were performed. Results: Post PSM, we identified 76 cases of lung cancer in school cooks during 259,819 person-years of follow-up. The age-standardized incidence was 199.8 (95% confidence interval [CI]: 120.7-278.9) and 166.8 (95% CI: 95.8-237.7) for school cooks and clerks, respectively. The subdistribution HR for school cooks post PSM was 1.72 (95% CI: 1.14-2.60). In the never-smoked subcohort, the subdistribution HR for school cooks post PSM was 4.23 (95% CI: 2.36-7.58). Conclusion: School cooks were at an elevated risk of developing lung cancer, likely due to exposure to cooking fumes, highlighting the need for improved ventilation and preventive measures in school kitchens to reduce lung cancer risk.