Purpose: Surgery remains the preferred treatment for head and neck of malignancies. Our purpose was to appraise the postoperative survival benefit of primary gingival squamous cell carcinoma (GSCC) patients without distant metastasis and to construct a nomogram in order to predict overall survival(OS).
Method: Patients who diagnosed with GSCC without distant metastasis and receiving active treatment between 2004 and 2015 were selected from the Surveillance, Epidemiology and End Results (SEER) database. The primary endpoint was OS. Univariate, multivariate Cox regression analysis and propensity score (PS) analysis were used to compare the association between surgical treatment and OS. The nomogram was to predict the 3-year and 5-year OS probabilities. The concordance index (C-index), the area under the curve (AUC), and calibration plot were used to evaluate the data performance of the nomogram model. The Decision Curve Analysis (DCA) curve was used to evaluate the clinical efficacy of the nomogram.
Results: We reviewed 2440 GSCC patients without distant metastasis. The median OS was 85 and 10 months in the surgery group and non-surgery group, respectively. After univariate and multivariate Cox regression analysis, surgery for the primary tumor was independent factors for OS. In order to balance the influence of confounding factors on the statistics, we used propensity score matching (PSM) analysis to evaluate the influence of surgery on OS, and the analysis results showed that OS still preferred surgical treatment at the primary tumor. In addition, independent influencing factors determined by univariate and multivariate Cox analysis were selected to prepare the survival prediction model of the nomogram. The model has well prediction performance. The C-index of the model is 0.708 and the AUC value of the 3-year and 5-year nomogram prediction model is 0.730. The calibration curve is also close to 45 degree. Both net benefit and net reduction curves showed that the nomogram model had good clinical benefit.
Conclusion: Our analysis suggests that surgery for primary site tumors is a viable option for GSCC patients without distant metastasis. Meanwhile, we have developed and verified a nomogram model which can effectively predict 3- and 5-year OS for GSCC patients, which has been proved to have well distinction, calibration abilities and clinical benefit. It can provide practical help for clinicians to make decision. Of course, our results and model need to be further validated with real-world data.