Use of preoperative PET-CT and survival of p16-negative oropharyngeal cancer.

No comparative study with a long-term follow-up period has evaluated the survival outcomes of preoperative 18-fluorodeoxyglucose positron emission tomography/computed tomography (18 FDG PET/CT) in patients with p16-negative OPSCC. We included patients with stage I-IVB p16-negative OPSCC undergoing surgery and categorized them into two groups based on whether they underwent preoperative 18 FDG PET/CT and compared their outcomes: the case group comprised patients who did not undergo preoperative 18 FDG PET/CT, whereas the control group comprised patients who underwent preoperative 18 FDG PET/CT. The findings of the multivariable Cox regression analysis revealed no association between preoperative 18 FDG PET/CT and overall survival (OS) in the case and control groups in the patients with stage I-III p16-negative OPSCC undergoing surgery (after multivariable adjustment, the hazard ratio [HR] was 1.12; 95% confidence interval [CI] = 0.86-1.48: P = 0.4028). However, we noted an association between preoperative 18 FDG PET/CT and OS in the case and control groups in the patients with stage IVA and IVB p16-negative OPSCC undergoing surgery (after multivariable adjustment, the HR of all-cause mortality for nonpreoperative PET/CT was 1.82 compared with preoperative PET/CT; 95% CI = 1.47-2.26; P < 0.0001). Preoperative 18 FDG PET/CT use was associated with a lower risk of mortality in the patients with stage IVA and IVB p16-negative OPSCC without metastasis.