This study aimed to test the new hypothesis that cancer surgery performed during holiday periods is associated with worse long-term prognosis than for non-holiday periods | International Journal of Cancer
This nationwide Swedish population-based cohort study included 228,927 patients during 1997-2014 who underwent elective resectional surgery for a cancer where the annual number of resections was over 100. The 16 eligible cancer sites were grouped into 10 cancer groups. The exposure, holiday periods, was classified as wide (14-weeks) or narrow (7-weeks). Surgery conducted inside versus outside holiday periods was compared regarding overall disease-specific (main outcome) and overall all-cause (secondary outcome) mortality.
Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, sex, comorbidity, hospital volume, calendar period, and tumor stage. Surgery conducted during wide and narrow holiday periods were associated with increased HRs of disease-specific mortality for cancer of the breast (HR 1.08, 95% CI 1.03-1.13 and HR 1.06, 95% CI 1.01-1.12) and possibly of cancer of the liver-pancreas-bile ducts (HR 1.09, 95% CI 0.99-1.20 and HR 1.12, 95% CI 0.99-1.26).
Sub-groups with cancer of the colon-rectum, head-and-neck, prostate, kidney-urine bladder, and thyroid also experienced statistically significantly worse prognosis following surgery conducted during holiday periods. No influence of surgery during holiday was detected for cancer of the esophagus-stomach, lung, or ovary-uterus. All-cause HRs were similar to the disease-specific HRs. The prognosis following cancer surgery might not be fully maintained during holiday periods for all cancer sites.
Full reference: Lagergren, J. et al. (2017) Prognosis following cancer surgery during holiday periods. International Journal of Cancer. Published online: 21 July 2017