Development and validation of a nomogram for predicting distant metastasis in oral squamous cell carcinoma

Objective This study aimed to identify and quantify risk factors for distant metastasis (DM) in patients with oral squamous cell carcinoma (OSCC). Methods A retrospective cohort study was conducted in patients with OSCC who underwent curative surgery and had histopathologically confirmed cervical lymph node metastasis. After excluding 16 patients with uncontrolled primary tumors, the remaining patients were assigned to a training cohort (n = 85) and a validation cohort (n = 41). Multivariable logistic regression was used to identify independent predictors of DM. These predictors were incorporated into a nomogram. The nomogram was internally validated using the training cohort and externally validated using the validation cohort to assess its predictive performance. Results Histological grade (adjusted odds ratio [aOR]: 3.75, 95% confidence interval [CI]: 1.19–13.51, p  = 0.02), number of positive nodes (aOR: 6.57, 95% CI: 1.55–35.16, p  = 0.01), and extent of extranodal extension (aOR: 1.50, 95% CI: 1.01–2.26, p  = 0.04) were identified as independent predictors of DM and incorporated into a nomogram. The internal and external validation cohorts demonstrated that the nomogram had good discrimination (area under the curve: 0.819 and 0.776, respectively), calibration, and clinical utility. Conclusion We developed a nomogram that accurately predicted the risk of DM in patients with OSCC. Clinical relevance: This tool may facilitate the development of individualized postoperative treatment strategies for patients undergoing curative surgery for OSCC.