Prognostic Utility of Neck Lymph Node-to-Primary Tumor Standardized Uptake Value Ratio in Oral Cavity Cancer

Abstract

We investigated the prognostic utility of preoperative neck lymph node-to-primary tumor maximum standardized uptake value ratios (NTRs) in oral cavity squamous cell carcinoma (OSCC). We retrospectively reviewed the medical records of 141 consecutive patients who were diagnosed as having OSCC and had received fluorodeoxyglucose-positron emission tomography within 2 weeks prior to radical surgery between 2009 and 2018. To determine the optimal NTR cutoff, receiver operating characteristic analysis for overall survival (OS) was executed. The NTR's prognostic value for disease-free survival (DFS) and OS were determined through Cox proportional hazards analysis and the Kaplan-Meier method. We determined the median (range) follow-up duration to be 35.2 (2.1-122.4) months. The optimal NTR cutoff was 0.273, and patients with a higher NTR (≥0.273) exhibited significantly worse DFS and OS (p = 0.010 and 0.003, respectively). A higher NTR (≥0.273) predicted poorer DFS (hazard ratio: 2.696, p = 0.008) and OS (hazard ratio: 4.865, p = 0.003) in multivariable analysis. We created a nomogram on the basis of the NTR, and it could accurately predict OS (concordance index: 0.774). Preoperative NTRs may be a useful prognostic biomarker for DFS and OS in patients with OSCC who have undergone surgery. NTR-based nomograms may also be helpful prognostic tools in clinical trials.

Keywords: FDG PET; biomarker; nomogram; oral cavity cancer; prognosis.

Figure 1

ROC analysis for OS prediction based on the NTR in 141 patients with OSCC. The AUC was 0.679 (p = 0.002; specificity = 44.4%; sensitivity = 87.2%), and 0.273 was determined to be the optimal NTR cutoff for OS prediction. Abbreviations: AUC, area under the curve; NTR, lymph node-to-primary tumor standardized uptake value ratio.

Figure 2

Kaplan–Meier curve of (A) OS and (B) DFS, stratified by the NTR. Worse prognosis was observed in patients with an NTR of ≥0.273. Abbreviation: NTR, lymph node-to-primary tumor standardized uptake value ratio.

Figure 3

(A) Nomogram for OS prediction incorporating independent prognostic factors in the multivariable analysis. Each prognostic factor’s contribution to risk is represented by the line segments and uppermost points. Total score is the sum of each factor’s points. Drawing a vertical line downward from the total score point yields the likelihood of 3- and 5-year OS. Calibration plots for (B) 3-year OS and (C) 5-year OS. The gray line at 45° represents perfect OS prediction; the predicted outcomes of the nomogram are represented by the blue line. The blue dots and bars reflect the performance of the nomogram and the 95% CIs for the OS predictions, respectively. Abbreviations: MD, moderately differentiated; NTR, lymph node-to-primary tumor standardized uptake value ratio; PD, poorly differentiated; WD, well differentiated.