Preoperative Inflammatory Ratios Poorly Discriminate Malignant From Benign Parotid Tumours
Jung Min Kim, So Young Jeon, Young Chan Lee, Su Il Kim, Young‐Gyu EunABSTRACT
Objective
To determine whether preoperative blood inflammatory ratios discriminate malignant from benign parotid tumours.
Methods
This retrospective single‐centre study included 204 patients undergoing parotidectomy (45 malignant, 159 benign); inflammatory‐index analyses included 45 malignant and 157 benign cases. The neutrophil‐to‐lymphocyte and monocyte‐to‐lymphocyte ratios were the two primary indices. Group differences were tested non‐parametrically with multiplicity control, discrimination by receiver operating characteristic analysis and association by multivariable logistic regression.
Results
Median neutrophil‐to‐lymphocyte and monocyte‐to‐lymphocyte ratios were higher in malignant tumours (2.00 vs. 1.81 and 0.203 vs. 0.166), but effect sizes were small. Areas under the curve were 0.608 (95% confidence interval 0.518–0.701) and 0.631 (0.520–0.735), respectively. At the sample‐derived neutrophil‐to‐lymphocyte threshold, sensitivity was 86.7% and specificity 35.7%. Additional inflammatory indices, histological subgroup analyses and sensitivity analyses did not materially improve discrimination.
Conclusions
Although the two primary ratios were higher in malignant tumours, their distributions overlapped substantially and discrimination was poor. These findings do not support their use as stand‐alone markers for preoperative malignancy risk stratification.