The case of 76-year-old male with three metachronous primary tumors including oral cancer is presented with the diagnosis, treatment and progress, as well as a literature review of multiple primary tumors. As to the cause of the three malignancies, drinking and smoking in the life history were considered strong carcinogenic factors. Since his father had suffered from stomach cancer, a hereditary predisposition could not be ruled out. Furthermore, the patient received radiation therapy by Linac, chemotherapy and surgery as treatment for the first primary tumor, which may have caused immunosuppression. These interacting factors are considered to have created a high risk situation.
Conflict of interest: None declared.