Development and validation of a nomogram for the prediction of lymph node metastasis within 2‐year postoperatively in cT1‐T2N0 oral squamous cell carcinoma

The current neck management for early oral squamous cell carcinoma (OSCC) has always been a controversial issue. A comprehensive model is necessary for predicting an individual's metastasis risk and appropriate patient counseling.A nomogram for predicting 2-year LNM in patients with cT1-2N0 OSCC was developed and validated using clinicopathological data from 642 patients from 2000 to 2018 in four hospitals, China.Three variables (pathology grade, depth of invasion, tumor-infiltrating lymphocytes) were included in nomogram. C-indices were 0.826 (95% CI: 0.786-0.866) and 0.726 (95% CI: 0.653-0.780) in the internal and external validation. Kaplan-Meier method found the 2-year LNM rate of high-risk group (35.8%) was much higher than that of the low-risk group (14.5%). The nomogram model has an advantage over the 8th AJCC TNM stage in predicting the individual 2-year LNM probability for early OSCC.Patients with low-risk nomogram score may receive neck observation; those with high-risk score should receive END.