and Objectives: The aim of this study was to analyze the risks of local recurrence, second primary tumor, and metastasis in oral squamous cell carcinoma (OSCC) patients and to present their prognosis after treatment. Methods: In this retrospective cohort study, 147 patients with oral squamous cell carcinoma (OSCC) who were older than 40 years were included using the data of 1973–2010 Surveillance, Epidemiology, and End Results (SEER) Program in the United States. The variables included gender,

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... ace, stage, histologic grade, tumor site, treatment modalities, and dates of diagnosis and death. Markov Multistate model was used for analysis. Results: At a median follow-up of 33 months, local recurrence, second primary tumor, and distant metastasis rates were 34.01%, 85.03%, and 17.01% respectively and 40.13% of the patients died. Patients with cervical lymph nodes were at risk of second primary tumor 1.37 (1.05-2.05) times higher than early stage patients and were 2.33 (1.29-4.18) times more likely to die. After one year, the risk of death for patients with local recurrence or second primary tumor was almost similar but after 5 years, the risk of death was higher for local recurrence than second primary tumor. Conclusion: Awareness of the next state and its time with respect to the patient's clinical status can be one of the appropriate methods for timely diagnosis and treatment to reduce the mortality rate of OSCC patients.